IAWA Bulletin n.s., Vol. 6 (4), 1985 365

SYSTEMATIC AND ECOLOGICAL WOOD ANATOMY OF THE

by

Phillip M. Rury Bailey-Wetmore Laboratory of Anatomy & Morphology, Harvard University Herbaria, Cambridge, MA 02138, U.S.A.

Summary Introduction The wood anatomy of 67 of Ery­ The Erythroxylaceae constitute a pantropi­ throxylum, and cal, woody dicotyledonous family of 200-250 was analysed from an ecological, systematic species of trees and shrubs, the vast majority be­ and evolutionary perspective. Wood anatomy longing to the P. Browne. variation within the pantropical genus Ery­ Erythroxylum exhibits maximum diversity in throxylum is explicable largely in relation to the neotropics, with at least 150 species rang­ ecological factors and correlative differences in ing from Mexico and the West Indies south­ plant architecture, leaf size and duration and ward to Bolivia, N. Argentina, Brazil and Uru­ foliar anatomy. Wood anatomy ranges between guay. Thirty species of Erythroxylum are en­ primitively mesomorphic and either meso- or demic to and adjacent islands, with at xeromorphically specialised. Wood inclusion least fourteen species in southern Asia and the type and leaf structural features are strongly Malayan archipelago, with three species each in interrelated, thus reflecting both taxonomic Australia and the Pacific proper. The other affinities and ecological profiles of the species. genera are the monotypicAneulophus africanus The most wood anatomically variable infra­ Benth., endemic to equatorial West Africa, generic taxa within Erythroxylum are the New Nectaropetalum Engl., with some nine species World sections Archerythroxylum and Rhabdo­ in tropical and southern Africa or Madagascar, phyllum, which include architecturally diverse, and Pinacopodium Exell & Mendonr;a, with deciduous and evergreen species. Due to the two species restricted to tropical Africa. intergrading ranges of wood anatomical varia­ Species of Erythroxylum occupy a wide tion among consectional and/or sympatric range of habitats, including lowland and mon­ Erythroxylum species, attempts to identify tane rainforests from sea level to an altitude of wood samples to the species level are ill-advised 2,000 metres. Some species of Erythroxylum in the absence of complementary ecological, and Nectaropetalum occur in savannas, open geographic and leaf structural data. The wood dry forest and other arid sites on a wide range anatomical uniformity of the cultivated cocas of granitic, sandy, serpentine or calcareous and their closest wild relatives of sect. Archery­ soils. Both paleo tropical and neotropical spe­ throxylum implies their shared mesophytic an­ cies of Erythroxylum reveal an interesting de­ cestry, whereas chemical, genetic and leaf gree of habital diversity, and include prostrate structural differences reflect the long term hu­ shrubs of xeric habitats, rosette shrubs and man selection, isolation and cultivation of Ery­ small trees of moist and wet forests, and tall throxylum within ecologically disparate regions canopy trees in everwet rainforests. According of South America. Wood (and leaf) anatomy of to Payens (1958), Malesian species of Erythro­ the drought sensitive E. coca var. coca is the xylum are confined to the substage of the most primitive and mesomorphic of the culti­ primary rainforest up to an altitude of 1,600 vated cocas, whereas both drought tolerant metres, avoiding areas subject to a dry season. varieties of E. novogranatense are more wood (and leaf) anatomically specialised. The closest Taxonomic history affinities of the Erythroxylaceae to other fami­ The genus Erythroxylum was first described lies of the -Linales- al­ by Patrick Brown in his 'Civil and Natural His­ liance occur among the most wood anatomical­ tory of Jamaica' (1756). Subsequently, Linnaeus ly primitive, mesomorphic and putatively basal, (1759) included the genus in his ~Systema Na­ evergreen taxa within each family. turae' using the spelling Erythroxylon, which Key words: Erythroxylaceae, Erythroxylum, has since been used by some authors (e.g., Mar­ cultivated coca, systematic and ecophyletic tius, 1843; Machado, 1972). Plowman (1976) wood anatomy. pointed out this inconsistency and established

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Erythroxylum as the correct spelling, based on ties of the Erythroxylaceae with other dicoty­ its priority of publication. ledonous families. In order to translate this Most early authors, including Reiche (1896) growing database into the standardised, com­ and Schulz (1907, 1931), limited the family to puter-coded format recommended by the two genera, Erythroxylum and . IAWA Committee (1981), a future paper on However, Stapf and Boodle (1909) concluded wood identification in the family will follow that Nectaropetalum should be included, due the study of additional specimens. to its similarity to Erythroxylum in both stem and leaf anatomy. A similar conclusion was Material and Methods reached by Oltmann (1968) on the basis of pol­ Woods from 140 specimens of 67 species len morphology. Normand and Cavayo (1951) and three genera were obtained from various advocated the inclusion of the new genus Pina­ xylaria and the collections of W. C. Evans, T. copodium Exell & Mendonya within the family Plowman and J. Schunke V. Wood of the rare, on the wood anatomical grounds and most monotypic Aneulophus africanus was not avail­ modern authors (e.g., Melchior, 1964; Hutchin­ able. Wood specimens and voucher information son, 1967, 1969, 1973) now agree that Aneulo­ are listed in Rury (1982), but are excluded for phus, Erythroxylum, Nectaropetalum and Pina­ the sake of brevity. Xylaria abbreviations are copodium form the family Erythroxylaceae. those recommended by Stern (1978) and her­ A long-standing taxonomic problem has been barium citations follow Holmgren and Keuken the resolution of infrageneric relationships of (1974). Ery throxylum. Schulz (1907, 1931) divided Specific gravity was estimated by dividing the genus into 19 sections, primarily on the the dry weight (g) of each sectioning block by basis of stipular and floral morphology. Pay ens the volume (ml) of water it displaced in a 50 ml (1958), however, noted that since Schulz'mono­ graduated cylinder. At the suggestion of Dr. graph, 'many species have become connected Regis B. Miller (pers. comm.), a moisture con­ by intergrades and consequently must be tent of 6% was assumed for all dried wood united.' Similar conclusions were reached by samples, and these specific gravity values were Plowman (pers. comm.) who noted that Schulz' then converted to basic specific gravity using sections 'are largely artificial and will have to the graphs provided by Miller (1981). Wood be submerged.' In addition extensive field stud­ macerations were made with hot (50°C) Jef­ ies of Erythroxylum throughout its neotropical frey's solution and thin sections were cut on a range have revealed a series of polymorphic sledge microtome. A few of the air-dried wood species complexes (Plowman, pers. comm.). The samples also were prepared for scanning elec­ interrelationships of these groups and their con­ tron microscopy using conventional techniques. stituent species are further obscured by prob­ Wood anatomical variation was statistically lems of synonymy, broad distributional ranges analysed with an analysis of variance (ANDY A) and related clinal morphological variation. 'package program' in a Tektronix 4051 com­ As noted by Tomlinson (1977), the resolu­ puter. Tracheary element dimensions are based tion of such complex problems in plant system­ on 50 measurements per wood specimen and atics requires a collaborative, integrated ap­ pore densities (vessel frequencies) were calcula­ proach. Fortunately, Plowman (1979, 1982, ted from ten counts per specimen. Solitary 1984a, b) has clarified the botanical identities pores and radial or tangential pairs were count­ of coca leaves grown commercially in South ed as single units, whereas radial multiples of America. as the sole natural source of the me­ three or more pores were scored as three or dicinal alkaloid cocaine and certain flavours more units, so as to accurately reflect relative used in the manufacture of Coca-Cola®. Plow­ conductive areas among specimens with com­ man's continuing taxonomic studies of Ery­ parable pore diameter. throxylum have provided accurately identified In order to permit general ecological inter­ wood samples, herbarium vouchers and perti­ pretations of wood anatomical variation, only nent ecological data for both wild and culti­ data from positively identified specimens of vated, tropical American species. Accordingly, known ecological origin were used to calculate this study was designed to: 1) provide a com­ species means. Paleotropical wood specimens prehensive wood anatomical circumscription were assumed to have been accurately identi­ for the Erythroxylaceae; 2) interpret wood fied and were excluded from calculations of anatomical variation from an ecological and species means only in the event of dubious evolutionary perspective: 3) elucidate the infra­ identity or incomplete documentation. Spec­ familial relationships of the Erythroxylaceae, imens were analysed in alphabetical sequence including the probable evolutionary origins of according to the infrageneric classification of cultivated coca and 4) further clarify the affini- Erythroxylum by Schulz (1907,1931).

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Standard deviations were calculated sepa­ E. rotundifolium from trees of unknown di­ rately for each taxonomic subset of specimens mensions. Sectioning blocks of unknown origin but are excluded for the sake of brevity. Spec­ in the plant are dark brown throughout and imen means and 95 % confidence intervals for suggest heartwood formation in E. ampulla­ pore diameter and density (frequency) are ceum, E. elegans, E. ellipticum, E. mexicanum, presented graphically (Figs. 1- 6) for selected E. monogynum and E. myrtoides. Basic specif­ taxa of Erythroxylaceae. Similar graphs of fibre ic gravity mostly 0.83 but ranges from 0.52 to and vessel element lengths for all wood speci­ 1.08, with a mean of 0.75 for woods with and mens are presented elsewhere (Rury, 1982). for woods lacking distinct heartwood. Lower Means for neotropical species were used for than average basic specific gravity most com­ analyses of wood anatomy in relation to habi­ mon in rather buoyant, cream-coloured woods tat, plant stature, leaf size classes (sensu Raun­ such as E. ecarinatum, E. macrocnemium, E. kiaer, 1934) and leaf structural types (sensu mannii, E. novogranatense vaL truxillense and Rury, 1981 , 1982). Habitat data for neotropi­ E. reticula tum. cal species of Erythroxylum were furnished by Growth rings mostly absent as viewed with a Plowman (pers. comm.). Information about hand lens, being faint to distinct without a plant habit, leaf size and duration, presented hand lens only in some samples of E. catarac­ in Appendix 1, were derived mostly from Plow­ tarum, E. confusum, E. ftmbriatum, E. macro­ man (pers. comm.) and Schulz (1907, 1931). phyllum and E. undulatum. False rings also These calculations of general character corre­ may appear due to the presence of circumfer­ lations were made manually and are only in­ entially discontinuous bands of reaction wood, tended to serve as preliminary data for use in especially in young, small diameter stems. comparing species. More sophisticated, com­ Growth increments or rings, however, are mi­ puterised studies of wood and leaf structural croscopically distinct and regularly to irregular­ character correlations, using multiple regression ly spaced in several species (Table 1). Growth and chi-square analyses of raw data (rather increments of most species conform to the than species means), will be executed and pub­ 'Type IB' rings described microscopically by lished in the future. Carlquist (1980): little differentiation into Wood anatomical indices of vulnerability growth rings, seasonal changes gradual, vessels (VULN) and mesomorphy (MESO) were cal­ smaller in latewood but not markedly so and culated from species means according to the other cell types unaffected. Growth increments formulae of Carlquist (1977). Wood anatomi­ are microscopically discernible due to conspic­ cal terms conform to the 'Multilingual glossary uous radial compression of latewood libriform of terms used in wood anatomy', published by fibres (Figs. 18, 31 , 33). Fibre and vessel diam­ the Committee on Nomenclature of the Inter­ eters and wall thickness, as well as pore densi­ national Association of Wood Anatomists ties, are uniform throughout the growth incre­ (1964). Xylem rays are typified according to ments of most species. In E. amazonicum (Fig. the classification of Kribs (1935), with occa­ 18), E. amplifolium and E. kapplerianum (Fig. sional use of terms from Czaninski (1977) and 27), however, vessels of the early wood are Gregory (1978). Terminology for xylary cell wid er and more numerous than in latewood, dimensions follows the suggestions of Chatta­ conforming most closely to rings designated as way (1932), Chalk (1938), the Committee on 'Type VI ' by Carlquist (1980). All woods are the Standardization of Terms of Cell Size diffuse-porous and those with microscopically (1937) and the Standard List of Characters distinct growth rings only rarely approach the (Committee IAWA, 1981). semi-ring-porous condition, with respect to ves­ sel density within a ring (Figs. 27, 31). Results Vessels moderately numerous to very num­ PhYSical properties. Sapwood mostly cream erous, 14- 262 per sq. mm among species (fami­ coloured to tan or light, reddish brown. Heart­ ly mean of 69 per sq.mm). Pores mostly soli­ wood absent from all smaller diameter stems tary or in radial mUltiples of 2- 8 (up to 28 examined (under 14 cm), including a 10 em dbh pores per mUltiple in E. coca). Percent solitary trunk sample of E. macrophyllum (Aw 33326). pores ranges from 16 % in E. novogranatense Heartwood medium to dark, reddish brown vaL truxillense to 100% in a sample of E. hy­ and sharply demarcated from a narrow, light pericifolium (Fig. 39), with a family mean of red-brown ring of sapwood in a sample of E. 63 %. Radial multiples range up to 72 % in E. laurifolium (Aw 21262) with an estimated williamsii (Fig. 32), with a mean for the family diameter of 14 - 15 cm. Medium to dark, red­ of 33 % (see also Figs. 21 , 24, 33,36). Tangen- dish brown heartwood also distinct in lumber samples of E. areola tum, E. monogynum and (tex t continued on page 373)

Downloaded from Brill.com10/03/2021 08:38:44PM via free access W Table I. Wood anatomical features of the Erythroxylaceae. 0\ 00 Key to characters: ECOL = Ecological preferences of species as defined by Plowman; M = mesic; SX = semi-xeric; X = xeric (see Appendix I). LFTP = Leaf structural type (Table 3): I = evergreen leaves with abundant, ramified fibro-sclereids; 2 = evergreen leaves without fibro-sclereids; 3 = deciduous leaves without fibro-sclereids. RNGS = Growth rings: 0 = absent; I = faint but inconspicuous; 2 = very prominent, but irregular (microscopically). %SOL = Relative percentage of solitary pores per sq.mm; remainder of pores typically in radial multiples. VEL = Mean vessel element length in Jilll. POM = Mean tangential pore diameter in Jilll. VEL: PDM = Mean length to width ratio of vessel elements. PONS = Mean pore density per sq.mm. FL = Mean fibre length in /.Lm. FL: VEL = Mean fibre: vessel element length ratio. VULN = Vulnerability index, following Carlquist (1977); VULN = POM/PONS. MESO = Wood anatomical mesomorphy index, following Carlquist (1977); MESO = (VULN) x (VEL). INCL = Wood inclusion types: S = silica grains in ray cells; P = prismatic crystals in axial parenchyma; PR = prismatic crystals in the cells of uni- or biseriate rays; B = both silica and prismatic crystals in their typical positions, within the same wood; A = crystals absent entirely.

Genus. section 1 and species of Erythroxylaceae ECOL LFTP RNGS %SOL VEL POM VEL:POM PONS FL FL:VEL VULN MESO INCL

Erythroxylum: Macrocalyx: (M-SX) (2) (0-1) (60) (646) (51) (12.7) (76) (1349) (2.1) (. 67) (433) (S) ;; ~ Downloaded fromBrill.com10/03/2021 08:38:44PM E. lucidum SX/M I 54 637 46 13.4 79 1337 2.1 .58 369 S > E. macrocnemium M 0 64 679 46 15.2 74 1476 2.2 . 62 421 S-B 0:1 E. E. macrophyllum M 1 0-1 61 630 57 11.9 77 1279 2.0 .74 466 S- B :r RhabdophyUum: (M- X) (1 - 3) (0-1) (60) (603) (49) (12.3) (72) (1213) (2.0) (.68) (410) (S;P,B) S· ::s E. amazonicum M 0-1 52 1020 59 17.4 31 1622 1.6 1.9 1938 S 1n E. amplum M 0- 1 67 712 45 16.1 85 1459 2.0 .53 377 S < ?- E. campinense M-SX 91 466 40 11.6 130 1046 2.2 .31 144 B 0\ E. citrifolium M- SX 1 0- 1 56 617 55 11.3 62 1205 1.9 .89 549 S ~ via freeaccess E. decidum SX-X 3 67 503 76 6.6 34 1401 2.8 2.2 1124 A \0 00 E. /imbriatum M 85 664 39 16.6 99 1299 1.9 .39 259 S VI (Rhabdophyllum ~ continued) ;..- til E. mucronatum M 47 594 54 11.0 69 1138 1.9 .78 463 S E. E. myrsinites M 2 49 408 37 11.0 140 1113 2.7 .26 108 P 1r 5' E. pelleterianum X 3 1 37 492 41 12.0 61 1041 2.1 .67 330 S ::I E. raimondii SX 3 o 52 379 48 7.8 92 1016 2.7 .52 197 P 1" E. rufum 3 33 478 49 9.8 108 1177 2.5 .45 217 P < SX-X o ~ E. squama tum M 0- 1 74 514 49 10.5 66 1033 2.0 .74 380 P 0\ E. stey ermarkii SX 3 55 626 44 14.2 119 1421 2.3 .37 232 B ~ E. suberosum X 1 1 60 580 52 11.2 79 1114 1.9 .66 383 S \0 00 Leptogramme: (M) (2) (0-1) (49) (512) (48) (10.7) (62) (1343) (2.6) (. 77) (396) (S- B) Vl E. pulchrum M 2 1 62 546 45 12.0 59 1437 2.6 .76 415 P E. ulei M 2 o 35 479 51 9.4 67 1249 2.6 . 76 364 S-B Heterogyne: (M-SX) (2-3) (0-1) (59) (430) (45) (9.6) (lOS) (1053) (2.5) (.43) (185) (P- B) E. areola tum M-SX 3 0-1 67 478 47 10.2 86 1179 2.5 .55 261 P E. minutifolium SX-X? 2? 403 941 2.3 P? E. rotundifolium SX-M 2 0-1 50 409 42 9.7 123 1038 2.5 .34 139 B Archerythroxy1um: (M-X) (1-3) (0-2) (49) (502) (44) (11.4) (115) (1162) (2.3) (. 38) (191) (P-B) E. amplifolium M 2 2 75 742 40 18.6 119 1651 2.2 .34 252 S E. argentinum SX 3 45 442 43 10.3 137 1117 2.5 .31 137 P Downloaded fromBrill.com10/03/2021 08:38:44PM E. brevipes SX 3 o 53 463 36 12.9 119 993 2.1 .30 139 P E. carthagenense SX-M 3 2 51 421 60 7.0 57 1276 3.0 1.1 443 P E. cataractarum SX-M 2 o 47 590 56 10.6 49 1030 1.7 1.1 649 P E. coca var. coca M 2 o 31 474 43 11.0 102 1023 2.2 .42 200 P E. confus{tm M-SX 3 0-1 33 431 50 8.6 86 1137 2.6 .58 250 P E. cuatrecasasii M 2 o 49 805 61 13.2 64 1613 2.0 .95 765 P E. cumanense SX 3 2 36 455 42 10.8 149 1052 2.3 .28 128 P E. densum SX 3 0-2 45 601 41 14.7 98 1502 2.5 .42 251 P via freeaccess W E. glaucum SX 3 1-2 50 446 46 9.7 99 1073 2.4 .46 207 P 0\ \0 w (Table 1 continued) -..J 0 Genus. section 1 and species of Erythroxylaceae ECOL LFTP RNGS %SOL VEL PDM VEL:PDM PDNS FL FL:VEL VULN MESO INCL

(Archerythroxylum continued)

E. haughtii SX 3 65 SIS 45 11.4 113 1058 2.1 .40 205 P E. havanense SX 3 0-2 48 478 33 14.5 177 1108 2.3 . 19 89 P E. kapplerianum M 2 1-2 79 579 39 14.8 90 1138 2.0 .43 249 P E. lineolatum SX-M 3 0 53 604 53 11.4 72 1134 2.2 .74 447 P E. mamacoca M 2 0 58 571 35 16.3 137 1248 2.2 .26 148 P E. mexicanum SX 3 I 47 587 54 10.8 74 1428 2.4 .73 428 P E. novogranatense SX 2 0 36 502 50 10.0 101 1133 2.3 .50 251 P E. novogranatense var. truxillense SX 2 0 16 356 48 7.4 88 1042 2.9 .55 194 P E. orinocense SX 3 1- 2 50 452 40 11.3 145 1165 2.6 .28 125 P E. paci/icum SX 2 50 310 32 9.8 262 979 3.2 .12 37 P E. shatona M 2 0- 1 50 480 34 14.1 171 1036 2.2 .20 96 P E. undulatum SX 3 69 382 41 9.2 90 1067 2.8 .46 176 P ;; ~ Downloaded fromBrill.com10/03/2021 08:38:44PM E. vernicosum M I 70 494 41 12.2 129 1095 2.2 .32 158 B ;I> E. williamsii SX- X 3 I 25 447 43 10.4 166 1049 2.3 .26 116 P I:l:) $:= Microphyllum: (M- X) (2) (0-2) (59) (463) (39) (11.9) (136) (1167) (2.5) (.29) (133) (P) [ E. cunei/olium X-SX 2 2 56 445 38 11.6 141 1174 2.6 .27 120 P S· ::l E. microphyllum X 2 0 58 367 43 8.6 121 991 2.7 .36 132 P ~ E. panamense M 2 0 63 577 36 16 145 1337 2.3 .25 144 P < Malanocladus: ~ 0\ E. mannii 3 2 36 505 87 5.8 30 1364 2.5 2.9 1465 P ~ via freeaccess Gonocladus: 'D 67 6.7 44 1153 1.5 P 00 E. corymbosum 2 0 68 452 2.6 678 Vl Sethia: )-~ E. monogynum SX? 0 44 412 54 7.6 72 1144 2.8 .75 309 P t:l:l c: Lagynocarpus: [ E. ampullaceum 2 0 85 562 80 7.0 24 1153 2.1 3.3 1855 P S· ::I Coe1ocarpus ( -) (2-3) (0-1) (48) (547) (73) (7.5) (65) (1337) (2.4) 0.1) (614) (P) 1n E. australe SX? 0 39 358 43 8.3 144 1095 3.1 .30 107 P <: ?-- E. cuneatum M-SX? 2 0 56 589 78 7.6 29 1484 2.5 2.7 1590 P 0\ E. delagoense SX? 1 49 475 44 10.8 112 1133 2.4 .39 185 P ~ E. ecarinatum M? 0 67 811 134 6.1 17 1462 1.8 7.9 6407 P -\0 00 E. ellipticum SX? 0 27 377 48 7.8 129 1071 2.8 .37 139 P Vl Venelia: E. hypericifolium 2? 0 100 683 116 5.9 14 1313 1.9 8.3 5669 P or S Pachy1obus: (-) (2-3?) (0) (72) (475) (50) (9.5) (90) (044) (2.2) (.56) (264) (P-S) E. elegans 0 54 486 59 8.2 62 991 2.0 .95 462 P E.lanceum 0 84 367 36 10.3 153 .24 86 P E. laurifolium 2 0 44 494 83 5.9 19 1300 2.6 4.4 2174 S E. laurifolium 0 74 518 47 11.0 80 1142 2.2 .59 306 P E. longifolium 0 82 443 43 10.3 110 911 2.1 .39 173 P E. macrocarpum 0 72 555 52 10.7 82 1046 1.9 .63 350 Downloaded fromBrill.com10/03/2021 08:38:44PM Nectaropetalum: N. zuluense 2? 0 87 558 46 12.1 83 1127 2.0 .55 307 PR Pinacopodium: P. congolense M? 2? 0 80 725 77 9.4 23 1445 2.0 3.3 2393 PR

I Sectional designations for Ery throxylum follow Schulz 0907, 1931).

2 Single specimen of doubtful identity (Kw S.n. # 8): anatomically atypical as compared with other samples of this species. via freeaccess w -.J 372 IAWA Bulletin n.s., Vol. 6 (4),1985

Table 2. Quantitative levels of wood anatomical variation in the Erythroxylaceae.

Character state Taxonomic occurrence

Mean fibre length: Under I mm ...... Erythroxylum elegans, E. haughtii, E. longifolium, E. microphyllum, E. minutifolium, E. pacificum. 1.0-1.5 mm ...... Most species of Erythroxylum; Nectaropetalum zuluense, Pinacopo­ dium congolense. Over 1.5 mm ...... Erythroxylum amazonicum, E. amplifolium, E. cuatrecasasii, E. den­ sum. Mean vessel element length: Under 400 j.LIIl ..••••. Erythroxylum australe, E. ellipticum, E. lanceum, E. microphyllum, E. novogranatense var. truxillense, E. pacificum, E. raimondii, E. un­ dulatum. 400-700 j.LIIl ••...... Most species of Erythroxylum; Nectaropetalum zuluense. 700-1020).Lm ...... Erythroxylum amazonicum, E. amplifolium, E. cuatrecasasii, E. ecari­ natum, Pinacopodium congolense. Mean pore diameter:

Under 40 ).Lm ..•••... Erythroxylum brevipes, E. cuneifolium, E. fimbriatum, E. havanense, E. kapplerianum, E. lanceum, E. mamacoca, E. myrsinites, E. pacifi­ cum, E. panamense, E. shatona. 40-60 j.LIIl Most species of Erythroxylum; Nectaropetalum zuluense. 60-80 j.LIIl Erythroxylum ampullaceum, E. corymbosum, E. cuatrecasasii, E. cu­ neatum, E. deciduum, Pinacopodium congolense. 80-134).Lm ...... Erythroxylum ecarinatum, E. hypericifolium, E. laurifolium, E. man­ nii. Mean pore density: Fewer than 40 mm-2 Erythroxylum amazonicum, E. ampullaceum, E. cuneatum, E. deci­ duum, E. ecarinatum, E. hypericifolium, E. lanceum, E. mannii, Pina­ copodium congolense. 40-100 mm-2 ••••••• 32 species of Erythroxylum; Nectaropetalum zuluense. 100-150 mm-2 •.•.•• 20 species of Ery throxylum. 150-200 mm-2 •••••• Erythroxylum havanense, E. lanceum, E. shatona, E. williamsii. More than 260 mm- 2 •• Erythroxylum pacificum. % Solitary pores: Fewer than 40% ...... Erythroxylum australe, E. coca, E. confusum, E. cumanense, E. ellipti­ cum, E. mannii, E. novogranatense, E. novogranatense var. truxillense, E. pelleterianum, E. rufum, E. ulei, E. williamsii. 40-70% ...... Most species of Erythroxylum. 70-100% ...... Erythroxylum amplifolium, E. ampullaceum, E. campinense, E. fim­ briatum, E. hypericifolium, E. kapplerianum, E. lanceum, E. laurifo­ lium, E. longifolium, E. macrocarpum, E. squama tum, Nectaropetalum zuiuense, Pinacopodium congolense. Vessel element length: width ratio: Less than 8.0 ...... Erythroxylum ampullaceum, E. carthagenense, E. corymbosum, E. cuneatum, E. deciduum, E. ecarinatum, E. ellipticum, E. hypericifo­ lium, E. laurifolium ? (K w s.n. # 8), E. mannii, E. monogynum, E. novogranatense var. truxillense, E. raimondii. 8.1-12.0 ...... Most species of Erythroxylum; Pinacopodium congolense. 12.1-15.0 ...... Erythroxylum brevipes, E. cuatrecasasii, E. densum, E. haughtii, E. havanense, E. kaPplerianum, E. lucidum, E. shatona. E. steyermarkii, E. vernicosum, Nectaropetalum zuiuense. 15.1-18.8 ...... Erythroxylum amazonicum, E. amplifolium, E. amplum. E. fimbria­ tum, E. macrocnemium, E. mamacoca.

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(Table 2 continued) Character state Taxonomic occurrence Fibre: vessel element length ratio: \.6-2.0 ...... Erythroxylum amazonicum, E. cataractarum, E. citrifolium, E. ecari­ natum, E. fimbria tum, E. haughtii, E. hypericifolium, E. macrocarpum, E. mucronatum, E. suberosum. 2.0-2.5 ...... Most species of Erythroxylum; Pinacopodium congolense. 2.6-3.2 ...... Erythroxylum australe, E. carthagenense, E. confusum, E. corymbo­ sum, E. cuneifolium, E. deciduum, E. ellipticum, E. microphyllum, E. monogynum, E. myrsinites, E. novogranatense var. truxillense, E. paci­ ficum, E. pulchrum, E. raimondii, E. ulei, E. shatona. Vulnerability index: Less than 0.3 ...... Erythroxylum cumanense, E. cuneifolium, E. havanense, E. lanceum, E. mamacoca, E. myrsinites, E. pacificum, E. shatona, E. williamsii. 0.3-\.0 Most species of Erythroxylum; Nectaropetalum zuluense. 1.1-2.9 Erythroxylum amazonicum, E. carthagenense, E. cataractarum, E. corymbosum, E. cuneatum, E. deciduum, E. mann;;. 3.0-8.3 Erythroxylum ampullaceum, E. ecarinatum, E. hypericifolium, E. laurifolium, Pinacopodium congolense. Mesomorphy index: Less than 50 ...... Erythroxylum pacificum. 75-100 ...... Erythroxylum havanense, E. lanceum, E. shatona. 100-500 ...... Most species of Erythroxylum; Nectaropetalum zuluense. 500-1000 ...... Erythroxylum cataractarum, E. citrifolium, E. corymbosa, E. cuatre­ casas;;. 1000-3000 Erythroxylum amazonicum, E. ampullaceum, E. cuneatum, E. deci­ duum, E. laurifolium, E. mann;;, Pinacopodium congolense. 5500-6500 Erythroxylum ecarinatum, E. hypericifolium.

tial parts or small pore clusters (3-4) rare, with often two-sized and larger than intervessel pits, a family mean presence of 4%. Vessel outline ranging from alternate, circular and half-bor­ mostly circular or radially elliptic, infrequently dered to procumbent cells, to transitional, sca­ angular as in wood of E. cuatrecasasii, E. macro­ lariform or fenestrate to square and erect ray cnemium, E. panamense and Pinacopodium cells (Fig. II). Vessel-ray pits typically larger congolense (Figs. 13, 15, 25). Vessel walls gen­ than intervessel pits, ranging between 2-30 pm erally of medium thickness (3-6 pm). Tangen­ (mostly 2-10 pm) high and 5-30 pm (mostly tial pore diameter very small to medium-sized 5-20 p.m) wide. In Nectaropetalum zuluense (32-134 pm), but mostly moderately small and Pinacopodium congolense (Fig. 14), both with a mean diameter of 61 pm for the family. intervessel and vessel-ray pits are 2-5 pm in Vessel elements moderately short to moderate­ diameter, exclusively alternate and simple or ly long (310-1020 pm), but mostly medium in slightly bordered. Thin-walled tyloses common length with a family mean of 535 pm. Ligules throughout the family (Fig. 13), but most common and often very long, constituting up abundant and often thicker-walled in E. aus­ to 50% (mostly 20-30%) of total vessel ele­ trale, E. ellipticum, E. monogynum and E. ori­ ment length. Perforations exclusively simple in nocense. mature wood, but occasionally scalariform Helical wall sculpturing (,striations') absent with 3- 5 bars per plate in the first formed sec­ from vessels of most species. Although identi­ ondary xylem. End wall inclination moderately cal to most other Erythroxylaceae in their al­ variable, even within a specimen, ranging from ternate, circular bordered, intervessel pits, an oblique (70°) to transverse. Intervessel pitting ex tra layer of undetermined origin occurs on alternate and circular bordered with pit diam­ the inner vessel walls of E. myrsinites (Figs. 8- eters mostly 2-5 pm (Figs. 7, 8,14), with larger 10). This layer consists of closely spaced and pits (6-8 pm) in E. deciduum. Vessel-ray pits coalescent, obliquely oriented, helical ridges of

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wall material. Intervessel pits are covered by very abundant only in E. areola tum, E. coca, E. these coalescent ridges except in areas where cuatrecasasii, E. glaucum, E. hypericifolium, E. transverse gaps occur between them, usually laurifolium, E. panamense and E. ulei (Figs. 24, over vessel-ray contact pits with procumbent 25 , 39). Most parenchyma is apotracheal-diffuse ray cells. Although not included in the data and paratracheal, with patterns ranging from summary for this report (Table I), a recently apotracheal-diffuse and para tracheal-scanty in acquired Chinese wood sample of Erythroxy­ E. deciduum, E. delagoense, E. fimbria tum, E. lum cf sinense YC. Wu (Aw 33382) contains steyermarkii and E. williamsii to unilaterally vessels with an identical wall sculpture. para tracheal-abaxial in woods of E. carthage­ Imperforate tracheary elements libriform nense, E. coca, E. novogranatense vars. and fibres, with medium or thick walls (2.5-10 Pinacopodium congolense (Fig 13). Various J.Lm). Pitting sparse or absent, with highly re­ amounts of apo- and para tracheal banded pa­ duced, slit-like apertures in most species. Pits renchyma, from 1- 4 (mostly 1-2) cells wide, few to moderately numerous on both radial may occur in E. ampullaceum, E. coca, E. cua­ and tangential walls, with diameters sometimes trecasasii, E. cuneatum, E. glaucum, E. hyperi­ ranging between 1-2 J.Lffi as in E. argentinum, cifolium, E. laurifolium (Kw s.n. #8), E. pana­ E. confusum, E. elegans, E. ellipticum, E. glau­ mense and E. shatona (Figs. 25 , 39). cum, E. laurifolium, E. lucidum, E. macrocar­ Wood inclusions of two types with three dis­ pum, E. mamacoca, E. orinocense, E. panamense, tribution patterns: 1) silica grains occurring E. pelleterianum, E. rotundifolium, E. rufum, singly in ray parenchyma; 2) prismatic crystals E. squama tum, E. undulatum and E. vernico­ (calcium oxalate) in the ray cells; 3) prismatic sum. Pit diameter infrequently 2-5 J.Lm, as in crystals in axial parenchyma cells (Figs. 23,37, E. amplifolium, E. campinense, E. hypericifo­ 40). Silica grains occur in ray cells of most Ery­ lium, E. longifolium, E. raimondii, E. subero­ throxylum species belonging to the neotropical sum, Nectaropetalum zuluense and Pinacopo­ sections Macrocalyx and Rhabdophyllum, but dium congolense. Libriform fibres very short to in very few species of other Erythroxylum sec­ long (911-1651 J.Lffi), but mostly short, with a tions in both the paleo- and neotropics (Table mean family length of 1218 J.Lffi . Fibres consis­ 1). Silica grains rarely occur in the rays of paleo­ tently square or rectangular in transverse out­ tropical species, appearing only in one sample line, with a tangential diameter of 8-25 J.Lffi . each of E. hypericifolium (Aw 21258) and 'E. Rays mostly heterocellular (Kribs' Type I1A) laurifolium' (K w s.n. #8, no voucher). Prismat­ and biseriate or triseriate, with procumbent ic crystals occur in square and erect ray cells body cells and from 2-15 (mostly 2-8) square only in 'Ery throxylum areola tum ' (K w s. n. and erect, marginal (wing) cells (Figs. 16, 26). #2, no voucher), Nectaropetalum zuluense and Uniseriate marginal ray extensions may con­ Pinacopodium congo/ense (Fig. 40). Silica grains nect vertically with two or more ray body seg­ and prismatic crystals never occur together in ments. Rays almost exclusively biseriate and individual ray cells or rays of the same sample nearly homocellular, composed mostly of or species. Most species of Erythroxylum, pan­ square and erect cells (Kribs' Heterogeneous tropically, lack ray silica but contain calcium Type IIA), only in paleo tropical species such as oxalate prisms that are restricted to the axial E. ampullaceum, E. cuneatum, E. delagoense, parenchyma. Both ray-silica and axial-prismatics E. ecarinatum, E. elegans, E. hypericifolium, E. appear in the same wood specimen very rarely, laurifolium, E. mannii and Pinacopodium con­ as in solitary samples of the neotropical E. cam­ golense (Figs. 35, 37). Rays almost exclusively pinense, E. macrocnemium, E. macrophyllum, uniseriate and nearly homocellular (Kribs' Type E. rotundifolium, E. steyermarkii (Fig. 23), E. III) only in E. lanceum and Nectaropetalum zu­ ulei and E. vernicosum. luense. Ray density only sligh tly variable among species, ranging between II-51 per sq.mm of tangential surface, with a family mean density Discussion of 27 rays per sq. mm (data omitted here; see Rury, 1981, 1982). Character variation Axial parenchyma abundance and distribu­ Selected graphs of statistical variation (means tion patterns highly variable and defying pre­ and 95 %confidence intervals) among specimens cise classification in to discrete types. Axial pa­ of Erythroxylaceae are presented in Figs. 1-6, renchyma essentially absent from wood of E. as a complement to species means shown in ecarinatum and E. mannii, and very sparse in Table I. Quantitative levels of variation, based E. kapplerianum, E. shatona, E. vernicosum and on Table 1, are summarised in Table 2 for the E. williamsii (Figs. 27, 32, 34), parenchyma sake of brevity and easy reference for compara­ moderately abundant in most species, being tive purposes.

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Woods of Nec taropetalum, Pinacopodium and regarded as primitive, whereas low VEL: PDM Old World Erythroxylum fall within the range and high FL: VEL ratios are indicative of greater of variability observed within the most diverse evolutionary specialisation. In woods of the of the neotropical Ery throxylum sections, Arch­ Erythroxylaceae, VEL: PDM and FL: VEL ra­ erythroxylum and Rhabdophyllum (Figs. 1- 6). tios are inversely correlated, a trend which also Interspecific variation in all features usually is conforms to the classical tenets of xylem evolu­ greater than that observed among multiple col­ tion. Erythroxylum species with the highest lections of the same species, although statisti­ VEL: PDM ratios also reveal the lowest FL: VEL cally significant differences may appear among ratios, as in neotropical mesophytes such as E. samples of both neotropical (e.g., E. citrifolium amazonicum and E. fimbriatum (Tables I & 2). = CITR, Figs. 1, 2) and paleotropical Ery throx­ This inverse relationship is most evident in high­ ylums (e.g., E. ampullaceum = AMPU, E. man­ ly specialised woods with low VEL: PDM but nii = MANN and E. monogynum =MONO, Figs. high FL: VEL ratios, especially in xerophytes 5, 6). Although specimens and species collec­ such as E. carthagenense, E. corymbosum, E. tively exhibit intergrading ranges of statistical deciduum, E. ellipticum, E. novogranatense var. variation in wood anatomy, the quantitative truxillense and E. raimondii (Tables 1 & 2). levels summarised in Table 2 may prove useful in specimen identification, especially in com­ Ecological considerations bination with geographic, ecological, ­ These patterns conform to general wood logical and qualitative xylem characters. evolutionary trends towards increased strength­ As would be expected in light of their shared ening and conducting specialisation of imper­ cambial origin, fibre and vessel element lengths forate and perforate tracheary elements (Carl­ reveal parallel variation patterns within major quist, 1975). The trend toward increased mor­ sections of Erythroxylum (Rury, 1982), thus phological differentiation and functional spe­ conforming to the general trends recognised for cialisation of all tracheary elements is especial­ tracheary elements among diffuse-porous dico­ ly pronounced along decreasing moisture and tyledons (Chalk & Chattaway, 1935; Cariquist, increasing altitudinal or latitudinal gradients, 1975). Species of Erythroxylum with the long­ both among various florulas (Carlquist, 1977; est fibres also produce the longest vessel ele­ Baas et aI., 1983) and within individual fami­ ments, whereas the shortest fibres and vessel lies or genera (Baas, 1973, 1976;Carlquist, 1975, elements similarly appear in the same species 1980; Dickison et aI., 1978; Van der Graaff & (Tables 1 & 2). Most woods of Erythroxylum Baas, 1974: Michener, 1981 ; Van den Oever et reveal little or no interdependence of individual aI., 1981; Rury & Dickison, 1984). However, as vessel element dimensions. Although the short­ is discussed below, wood anatomical specialisa­ est vessel elements often are the most narrow tions in Erythroxylum also may be of a meso­ as well (e.g., E. australe, E. lanceum and E. pa­ morphic nature, as in tall rainforest trees of cificum; Tables 1 & 2), an inverse relationship is both the neo- and paleotropics. not always evident. Vessel elements of E. ama­ Both vulnerability (VULN) and mesomorphy zonicum and E. amplifolium, for example, are (MESO) indices, liS defined by Carlquist (1977) v~y long but only of average width (Tables 1 and Carlquist and DeBuhr (1977), are included & 2). Only a few arborescent species, such as in Tables 1-3. Wood with many, narrow vessels E. ecarinatum and Pinacopodium congolense , is widely regarded as safer and less vulnerable possess both atypically long and wide vessel to functional disruption than wood with fewer elements (Tables 1 & 2). At all taxonomic levels, and wider pores (e.g., Zimmermann, 1978, 1983). pore diameter is inversely proportional to pore Carlquist's VULN index, therefore, may be both density (Figs. 1-6), a trend widely recognised ecologically and physiologically significant with for dicotyledons (Carlquist, 1975; Dickison, respect to plant water relations. 1980; Dickison et aI., 1978; Van der Graaff & According to Carlquist's (1977) floristic in­ Baas, 1974; Van Vliet, 1979). The narrowest terpretations for major plant taxa and life forms pores consistently occur with both the highest throughout the world, species that are widely frequency and incidence of radial multiples, regarded as typical xerophytes on ecological whereas atypically wide vessels have a mostly and morphological grounds usually reveal meso­ sparse and solitary distribution (Tables 1 & 2). morphy indices below 75, whereas classical me­ Length: width ratios of vessel elements (VEL: sophytes mostly have mesomorphy indices of PDM), and fibre: vessel element length ratios 200 or greater. The ecophysiological significance (FL: VEL) normally serve as indices of phylo­ of Carlquist's mesomorphy index, however, is genetic advancement (Bailey, 1957; Carlquist, uncertain due to the unresolved adaptive role 1975; Dickison, 1975). High VEL:PDM and (if any) of vessel element length (see Baas, 1982; concomitantly low FL: VEL ratios are widely Zimmermann, 1983; Rury & Dickison, 1984).

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Common legend to Figs. 1-6 on pages 376 -381. Statistical data (means and 95% confidence in­ tervals) for pore diameter and pore density (frequency) for individual wood samples of taxa of Erythroxylaceae. Four-letter codes designate species and specimen codes bearing an asterisk were determined by Plowman from herbarium vouchers.

10 20 30 40 50 60 70 80 90 pm

RHABDOPHYLLUM: AMAZ 1---*-1 Uw 4986* AMAZ r---+---l FHOw 14642 AMPL r---+---l SJRw 12112

AMPL i---+--I PLOW 6977*

CMPI i---+--I PRA 18722* (iso)

CITR ~ Uw 17708* CITR'---"""'" Uw 3346- CITR 1---+--1 Uw 4215* CITRI---*--i Uw 1422-

CITR f---*-.l Uw 6725-

CITR i---+--I Uw 1877-

CITR i---+--I PLOW 5986*

DECD ~ Uw 14119* FIMB~ PLOW 6878*

MUCR i---+--I SJRw 35898*

MUCR f--+---j FHOw 20652*

MUCR ~ PLOW 5683* MYRS i---+--I Uw 14227* PELL r---+---l SJRw 53041 RAIM r---+---l Aw 30670-

RAIM 1---+--1 Aw 30672* SQMT r---+---l Uw 1889-

SQMT ~ Uw 4719-

TEST~ SJRw 35512* NECTAROPETALUM: ZULU r--+--1 SJRw 32928

PINACOPODlUM: CONG ~ FHOw 18268

Overa! mean = 49.3 pm (s.e. = 1.8 pm)

Fig. 1. Pore diameter of Erythroxylum sect. Rhabdophyllum; Nectaropetalum and Pinacopodium.

Zimmermann (1978) commented that vessel posed by Carlquist (1977). Since tracheary ele­ element length is 'functionally meaningless, in­ ment lengths of diffuse-porous woods provide sofar as we know', whereas total vessel length is a relative phylogenetic index for species (Chalk functionally adaptive in a predictable way (Zim­ & Chattaway, 1935), Carlquist's (1977) formula mermann, 1983). A more acceptable index of for the mesomorphy index might best serve as wood anatomical mesomorphy would integrate a composite, 'ecophy1etic' instead of 'ecophys­ the vulnerability index with total vessel length, iological' index of wood anatomy. rather than with vessel element length as pro- Vulnerability and mesomorphy indices of

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20 40 60 80 100 120 140 160 mrn- 2

Uw4986* : RHABDOPHYLLUM AMAZ I I FHOw 14642 AMPL I I SJRw 12112 AMPL I • I PLOW 6977* CMPI I • I PRA 18722* (iso) CITR I • I Uw 17708* CITR I I Uw 3346*

CITR I I Uw 4215* CITR I I Uw 1422* CITR I I Uw 6725*

CITR I • I Uw 1877*

CITR I I PLOW 5986*

DECO I • I Uw 14119* FIMB I I PLOW 6878* MUCR I I SJRw 35898* MUCR I • I FHOw 20652* MUCR I • I PLOW 5683*

MYRS I • I Uw 14227*

PELL I • I SJRw 53041

RAIM I • lAw 30670* RAIM I I Aw 30672* SQMT I I Uw 1889*

SQMT I • I Uw 4719* TEST I I SJRw 35512*

PULC I • I Aw 25416* LEPTOGRAMME

ULEI I • I SCHU 4304*

CONG I • I FHOw 18268 PINACOPODIUM

ZULU I I SJRw 32928 : NECTAROPETALUM

Overa! mean = 70 mm- 2 (s.e. = 4.1 mm-')

Fig. 2. Pore density of Erythroxylum sect. Rhabdophyllum & Leptogramme; Nectaropetalum and Pinacopodium.

Erythroxylaceae often are correlated with fibre I & 2). This combination of xylem features thus length, VEL: PDM and FL: VEL ratios, although constitutes both a primitive and mesomorphic the degree and nature of such correlations are profile, which is most common in shrubs and not consistent throughout the family. Woods trees of mesic forests. In contrast, the lowest with very high indices of vulnerability and indices of vulnerability and mesomorphy occur mesomorphy may reveal high VEL: PDM and in species with the lowest VEL: PDM and high­ low FL: VEL ratios, as well as the longest tra­ est FL: VEL ratios and the shortest, narrowest cheary elements and thinnest, most angular ves­ and thicker-walled tracheary elements. Wood sel walls (e.g., E. amazonicum, E. cataractarum, of these xerophytes, such as E. ellipticum, E. E. cuatrecasasii, and E. macrophyllum, Tables novogranatense var. truxillense (Trujillo coca)

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25 30 35 40 45 50 55 60 65

AMPF I • I Uw 6367* ARGE I • I Uw 14120a* CART I 1 SJRw 22510*

CATA I 1 ZARU 1383* COCA 1 1 PLOW 5792* **CULTIVATED" COCA 1 I PLOW 6060*

"COCAS" ~-~ :::

NOVO I 1 Aw 236* (branch wood) CUAT I • I SJRw 42928* CUMA I 1 PLOW 7673* DENS I I Aw 30669*

DENS 1 I PLOW 7666- GLAU I • I MADw 10440 GLAU I • I PLOW 5430* GLAU 1 I PLOW 5435* HAUT 1 • 1 PLOW 5254* HAVAI • I Aw21269* HAV A I 1 MADw 28827- KAPPI • IUw21771*

LINE I • 1 BROA 6054 MAMA I I PLOW 5959* MAMA I I MADw 15500 MEXI 1 I SJRw 2947* HAUT 1 I Aw 30671 * ORIN f-I - ....~ --'I SJRw 28456* PACI I • 1 PLOW 5520* SHAT I 1 PLOW 5533* SHAT I • I PLOW 6046*

UNDU 1 • I PLOW 7667* VERN I • 1 SJRw 35497* WILL I • I PLOW 7730*

Overa1 mean; 44 pm (s.e. ; 1.3 pm)

Fig. 3. Pore diameter of Erythroxylum sect. Archerythroxylum.

and E. raimondii may thus be regarded as xero­ individual species and specimens (Tables I & 3), morphically specialised in an ecophyletic sense. thereby supporting the ecological and floristic A third wood anatomical profile may be refer­ interpretations of wood anatomy of Carlquist red to as mesomorphically specialised, due to a (1975, 1977, 1980) and Baas et al. (1983). Al­ combination of high vulnerability and meso­ though primitively mesomorphic xylem tissues morphy indices with specialisations such as low mostly are confined to Ery throxylum species VEL: PDM and high FL: VEL ratios, as well as of small stature in the mesic forest understory rather short, thick-walled fibres and vessel ele­ in the neotropics, this profile sometimes ap­ ments. Tall rainforest trees and other species pears unexpectedly in xerophytes ofless favour­ with wide, sparse, mostly solitary vessels and able habitats, as in the deciduous E. pelleteria­ specialised, fenestrate vessel-ray pitting to near­ num and the scIerophylious E. suberosum (Table ly homocellular rays fall within this group, I). The most obvious explanation for such ex­ such as the paleotropical E. cuneatum, E. ecari­ ceptions is that stem and lor foliar features may natum and E. mannii (Tables I & 2; Figs. 11,34, serve to insulate or 'buffer' (sensu CarJquist, 35,38). 1977, 1980) these mesomorphic, primitive and Wood anatomy in Erythroxylum usually re­ rather vulnerable xylem tissues from adverse flects the ecological conditions experienced by conditions of their aerial microhabitats. Among

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50 100 150 200 250 300 mm-2

AMPF I I Uw 6367· ARGE I I Uw 14120a· ARGE I lAw 21264* CART f---*---I SJRw 22510* CATA ~ ZARU 1383* COCA f----*--I PLOW~792* COCA f----*--I PLOW 6060* **CULTIV ATION ** TRUX I • I PLOW 5600* **COCAS** NOVO I----*----i PLOW 5272* NOVO I I Aw 236* (branch wood) CUAT I I SJRw 2928* (iso) CUMA 1----*----1 PLOW 7663* DENS r----+--1 Aw 30669* DENS f---*---I PLOW 7666" GLAU I IMADw 10440 GLAU I • I PLOW 5430* GLAU f---*---1 PLOW 5435* HAUT I I PLOW 5254* HA V A I---*-----l Aw 21269* HAV A !----*---I MADw 28827* KAPP f----*--I Uw 21771* LINE ~ BROA 6054* MAMA f----*--I PLOW 5959" MAMA I • I MADw 15500 MEXI I I SJRw 2947* HAUT f-----*----I Aw 30671* ORIN f-*---1 SJRw 28456* PAC I f-*---1 PLOW 5520* SHAT I I PLOW 5533* SHA T I I PLOW 6046* UNDU I • I PLOW 7667" VERN 1----*----1 SJRw 35497* WILL I I PLOW 7730*

Overa! mean; 119 mm- 2 (s.e. ; 7.3 mm-2)

Fig. 4. Pore density of Erythroxylum sect. Archerythroxylum. neotropical erythroxylums, unspecialised, me­ soils and substrata (Rury, 1982). Neotropical somorphic xylem tissues occur in dry or sea­ species with silica grains in their ray tissue usu­ sonal habitats only within deciduous or ever­ ally inhabit soils of siliceous origin, as in cerra­ green-sclerophyllous species of sections Arch­ do, savanna and forest vegetation overlying the erythroxylum and Rhabdophyllum (Table 1). Brazilian and Guiana shield formations, con­ In such cases, foliar scleromorphy may serve to sisting of either granite or metamorphosed ig­ minimise water demands on the xylem, while neous and clastic rocks (Eiten, 1972; Heyligers, xylem tissues of drought-deciduous species 1963; Prance, 1978). A similar correlation is evade these harsh conditions altogether (cf. suggested by published reports of silica in neo­ Rury & Dickison, 1984). tropical timbers (Amos, 1951, 1952; Quirk, Wood inclusions seem to reflect the chemical 1980; Ter Welle, 1976a, 1976b), which are es­ nature of the soil and parent rock over which pecially common in these same upland regions species of Erythroxylaceae occur. Most species overlying the shield formations in Brazil, the of Erythroxylum as well as Nectaropetalum Guianas and Surinam where siliceous soils of­ and Pinacopodium contain calcium oxalate ten predominate. crystals in their wood parenchyma, and often Lewin and Reimann (1969) found a correla­ these species are more common over calcareous tion between the amount of silica in the soil (as

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40 60 80 100 120 140 j.I.ffi I I I I I ERYTHROXYLUM: MANN ...... -. RBHw 8152 MANN f----*---l RBHw 9924 MANNf----*---l Kw s.n. #10 CORY ~ MADw 28826 MONOf-+---l Aw8112 MONOI---*--I Kw s.n. #12 MONO 1---*--1 SJRw 3816

AMPU f---*--1 RBHw 3475 AMPU J..-..+---; MADw 28823

LANC f----+---< Aw 2668 AUST ~ Kw s.n. #3 CNEA ...... -..l Kw s.n. #4 CNEA f---+---l Kw s.n. #5 CNEAJ..-..+---; MADw 22225 CNEA...... -..l SJRw 50411

DELA ~ SJRw 32668

ECAR ~ Uw 18165 ELPT f---+--f Aw 26620 HYPE...... -..l Aw 21258 LAUF 1---*--1 Kw s.n. #8 ELEG f----*---l MADw 28828 LAUF f-+---l Kw s.n. #9 LAUF f-+---l Aw 21262 LNGF 1---*--1 EVANS B3 LNGF 1---*--1 EVANS B4 LNGF ~ EVANSB6

MCRP ~ EVANS C7 ZULU ~ SJRw 32928 : NECT AROPETALUM CONG t-+-l FHOw 18268 : PINACOPODIUM

Overa1 mean = 66 j.I.ffi (s.e. = 2.2 j.I.ffi)

Fig. 5. Pore diameter of paleotropical Erythroxylum; Nectaropetalum and Pinacopodium. monosiIicic acid) and that found in the , nomic utility of mineral inclusions in plant tis­ where Scurfield et al. (1974) noted that there sues. has been no attempt to correlate the uptake of Growth rings were reported for tropical trees monosilicic acid by trees either with its concen­ by Zimmermann and Brown (1971), who noted tration in the soil or with transpiration rates. that a new ring often corresponds to each The role of genotype versus ecological factors growth flush and that cambial activity in ever­ in mineral accumulation by plants, however, green species with intermittent growth is cor­ hardly is clarified by this circumstantial evi­ related with bud activity. Growth rings in Ery­ dence. Careful floristic studies of mineral accu­ throxylum are most common in seasonal habi­ mulation in relation to soil chemistry, and ex­ tats, especially in the wood of deciduous spe­ perimental studies within ecologically wide­ cies (Table I). Long radial multiples of rather spread genera such as Erythroxylum , are need­ narrow (under 50 /-lm) vessels are also more ed to resolve this problem and thereby evaluate common in deciduous species of seasonally dry the relative phylogenetic importance and taxo- habitats, and often seem more abundant in the

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o 20 40 60 80 100 120 140 160 mm-1

:ERYTHROXYLUM MANNI • I RBHw 9924 MANNI I Kws.n.#10 CORY I I MADw 28826 MONO I I Aw 8112 MONO I I Kw s.n. #12 MONO I I SJRw 3816 AMPU I • I RBHw 3475 AMPU I I MADw 28823 LANC I • I Aw 2668 AUST I • I Kw s.n. #3 CNEAI I Kw s.n. #4 CNEA I I Kw s.n. #5 CNEA , , MADw 22225 CNEA , I SJRw 50411 DELA I t SJRw 32668 ECAR' I Uw 18165 ELPT I • I Aw 26620 ELEG I I MADw 28828 HYPE, , Aw 21258 LAUF I • , Kw s.n . #8 LAUF I • , Kw s.n. #9 LAUF I I Aw 21262 LNGF I • I EVANS B3 LNGFI • I EVANS B4 LNGF I • 'EVANS B6 MCRP I • I EVANS C7 ZULU I • I SJRw 32982 : NECTAROPETALUM CONG I • 'FHOw 18268 : PINACOPODIUM

Overal mean = 64 mm- 1 (s.e. = 4.9 mm-1 )

Fig. 6. Pore density of paleo tropical Erythroxylum; Nectaropetalum and Pinacopodium.

earlywood of each growth increment, suggest­ relationships among plant habit, foliar struc­ ing their development in response to flushes of ture and wood anatomy, which collectively shoot growth. may reflect the ecological conditions experi­ As noted by Larson (1964), the environment enced by individual plants and species. influences wood formation only indirectly, via its direct influence on shoot morphogenesis Correlations with plant habit and leaf structur­ and leaf structure. Ecological factors which al type alter the architecture, stature, shoot develop­ Wood anatomy of Erythroxylum appears ment, phenology and leaf structure of woody closely correlated not only with habitat but plants thus can be expected to indirectly and also with interspecific differences in plant stat­ commensurately influence xylem differentia­ ure, architecture and foliar features such as du­ tion and mature anatomy (cf. Kramer & Koz­ ration, size, sclereid content and other anatom­ lowski, 1979; Zimmermann & Brown, 1971 ). It ical details (Rury, 1981, 1982). Rury and Dicki­ is thus advisable to carefully consider the in ter- son (1984) have reviewed the parallel occur-

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rence of these trends in various families of di­ gradient, within each leaf structural category cotyledons, with detailed discussions of speci­ (Table 3). fic examples in Erythroxylum and the unre­ Wood structure is both more uniformly lated, paleotropical genus Hibbertia Andr. (Dil­ primitive and mesomorphic among evergreen leniaceae). These multiple, plant structural cor­ Erythroxylum species with wood ray silica and relations as seen within Erythroxylum are brief­ sc1ereid-rich foliage than among plants which ly reviewed below 'and summarised statistically lack these foliar sc1ereids and silica grains, de­ in Table 3. spite the ecologically widespread occurrence of A combination of large, evergreen foliage each xylem and foliage type (Tables I & 3). and rather primitive, mesomorphic wood anat­ Trends of increasing xylem xeromorphy along omy is most common in Erythroxylum species a decreasing moisture gradient also are more of shady, wet forest, understory habitats, such pronounced among evergreen erythroxylums as E. amplum, E. coca, E. cuatrecasasii, E. ma­ without foliar sc1ereids than are parallel trends crocnemium and E. mamacoca. Wood of these among species within each of the other leaf mesophytes is unspecialised and contains long structural categories (Table 3). Statistical dif­ tracheary elements, rather sparse, medium­ ferences in wood anatomy often are greater sized vessels with thin walls and an angular out­ among Erythroxylum species with different line, and high VEL: PDM ratios (Tables 1-3; foliage types than those observed among eco­ Figs. IS, 16,23,25,29). As noted by Carlquist logically disparate plants with similar leaf anat­ (1966, 1975), this xylem anatomy is typical of omy (Table 3). As noted previously, Larson rosette trees and other understory mesophytes (1964) demonstrated experimentally that the which transpire at a slow and steady rate, due environment influences xylem anatomy in­ to their constant quantity of leaves and aseaso­ directly via its direct influence upon foliar de­ nal climate. Field studies of Erythroxylum in velopment and structure. It is thus not surpris­ Peru during 1981 and 1982 revealed uniformly ing that wood anatomy in Erythroxylum is of­ slower rates of foliar transpiration in under­ ten more directly related to leaf structural type story shrubs of E. coca, E. macrocnemium and than to the ecological provenance of the indi­ E. mamacoca than were measured in small trees vidual plant or species. of E. mucronatum growing nearby (c. 30 m) in Several Erythroxylum species of the Brazilian full sun at the forest margin (Rury, unpublish­ cerrado vegetation have been described as ed data). The more rapid transpiration rates in phreatophytes, which have deep taproots that E. mucronatum presumably reflect its sunnier reach the water table underlying very deep and microhabitat, greater stature, wider vessels nutrient-poor, sandy soils (Eiten, 1972). The (Table 1) and more abundant, heliomorphic scleromorphic foliage of such plants has been foliage. shown to transpire freely and continuously in Mesophytic Erythroxylum species with ever­ the xeric environment of the cerrado even dur­ green or deciduous, mesomorphic foliage of ing the dry season (e.g., E. suberosum - Rawit­ medium size may occur as tall trees of lowland scher, 1948; see also Ferri & Labouriau, 1952; rainforests, such as E. cuneatum, E. ecarinatum, Ferri, 1953, Coutinho & Ferri, 1956). The scle­ E. mannii and E. monogynum. These and other, reids of these leaves may prevent wilting or col­ truly arborescent (15-30 m) erythroxylums lapse in the face of severe water stress, and may possess the longest tracheary elements, widest serve to buffer the unexpectedly mesomorphic and least numerous vessels, lowest VEL: PDM and un specialised xylem tissues from the harsh, ratios, and highest vulnerability and mesomor­ hot and very dry aerial micro-environment of phy indices observed within the genus (Tables the cerrado (e.g. E. suberosum, Table 3). 1-3; Figs. 13, 17,34,36,38). The deciduous habit appears to have arisen At the opposite extreme, xerophytic erythro­ more than once within the Erythroxylaceae. xylums of diminutive stature (less than 2 m), Many species belonging to diverse sections of and those with very small leaves, consistently Erythroxylum, for example, reveal c1inal varia­ possess xeromorphic wood anatomical speciali­ tion in leaf size, form, venation and anatomy, sations such as the shortest tracheary elements, along a gradient from evergreen mesophytes to narrowest, thickest-walled and most numerous deciduous xerophytes (Rury, 1981,1982; Rury vessels, lowest VEL: PDM and highest FL: VEL & Dickison, 1984). Along this gradient leaf ratios, and lowest indices of vulnerability and blades become thinner, with more slender veins mesomorphy observed within the genus. These and a more regular, homogeneous and ortho­ parallel trends of xylem specialisation, in rela­ gonal reticulum of low and high vein orders. In tion to reductions in plant stature and leaf size, the American tropics, Erythroxylum species are reiterated among Old and New World Ery­ with deciduous leaves differ from their ever­ throxylum species along a decreasing moisture green counterparts in wood inclusion type,

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Table 3. Wood anatomy of neotropical Erythroxylum in relation to plant habitat, habit and leaf structural type. 1

Category (number of species) HABIT LSMX FL VEL PDM VEL:PDM PDNS VULN MESO

Evergreen with fibro·sclereids (12) 10.4 4.1 1203 605 49 12.3 83 .59 357 Mesic (8) 11.9 4.3 1300 663 49 13.6 79 .62 411 Semi·xeric (3) 8.7 3.7 1196 573 47 12.2 90 .52 299 Xeric' (1) 3.0 4.0 1114 580 52 11.2 79 .66 383

Evergreen without fibro·sclereids (17) 5.7 3.4 1121 460 41 1l.2 119 .34 158 Mesic (10) 6.1 3.8 1285 567 36 15.8 109 .33 187 Semi·xeric (6) 5.9 2.9 1086 445 43 10.3 126 .34 152 Xeric 3 (1) 0.6 2.0 991 367 43 8.6 121 .36 130

Deciduous without fibro·sclereids Semi·xeric (18) 5.5 3.6 1168 489 47 10.4 103 .46 223

Overall (47) 6.8 3.7 1163 517 44 11.8 105 .42 217 Mesic (18) 8.6 3.9 1293 615 43 14.3 94 .46 281 Semi·xeric (27) 5.9 3.5 1150 502 46 10.9 106 .43 218 Xeric (2) 1.8 3.0 1053 474 48 9.9 100 .48 228

1 Wood anatomical characters as defined in Table 1; HABIT = mean maximum height in metres; LSMX = mean maximum leaf size class as defined in Appendix 1. All means calculated using individual species means. , Erythroxylum suberosum, a phreatophyte of the Brazilian cerrado.

3 Erythroxylum microphyllum, a tiny-leaved subshrub from Argentina, Paraguay and the Brazilian cerrado.

growth ring prominence, tracheary element di­ wood anatomical specialisation in conjunction mensions, and vessel outline, wall thickness and with the acquisition of deciduousness (cf. Rury, distribution patterns (Tables 1 & 3). Most Ery­ 1981,1982; Rury & Dickison, 1984). throxylum species with distinct growth rings are deciduous, such as E. carthagenense, E. cu­ In trafamilial relationships manense, E. densum, E. glaucum, E. havanense, Genera of Erythroxylaceae differ primarily in E. mannii and E. orinocense (Table 1). Interest­ their reproductive morphology, whereas often ingly, tylose formation is most common in ery­ there are fewer vegetative structural differences throxylums of dry habitats, both in the Old between genera than among species or sections (e.g., E. australe) and New World tropics. In a of Erythroxylum (Rury, 1981, 1982). Nectaro­ wood sample of the neotropical E. orinocense, petalum and Pinacopodium share a rather prim­ the presence of tyloses in vessels immediately itive and mesomorphic wood anatomy and/or adjacent to the cambium suggest that tylose large, mesomorphic foliage similar to that of formation occurs concomitantly with foliar ab­ Aneulophus africanus, with many evergreen, scission, since this wood specimen was collect­ wet forest erythroxylums of the neotropical ed from a plant in the process of dropping its sections Archerythroxylum, Grandifolium, Ma­ leaves. Although wood of only one Nectarope­ crocalyx, Megalophyllum and Rhabdophyllum talum species was studied anatomically, a paral­ (Rury, 1982). These taxa thus appear as floris­ lel series of evergreen to deciduous leaf struc­ tic and plant structural analogues of one another tural types along a decreasing moisture gradient and presumably occupy a basal phylogenetic within this African genus imply similar trends in position within the Erythroxylaceae.

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Evergreen species with wood ray silica, foliar wide range of wood (and leaf) structural profiles sclereids and striated stipules are normally re­ (e.g. Archery throxylum, Rhabdophyllum; Table stricted to the neotropical sections Macrocalyx I; Figs. 1-4). and Rhabdophyllum, whereas the vast majority The phenetic convergence among many spe­ of evergreen Erythroxylum taxa which lack fo­ cies of Schulz' large neotropical sections have liar sclereids and striated stipules possess pris­ led to the recognition of several polymorphic matic crystals in their wood axial parenchyma species complexes or 'problem groups' by Plow­ (Rury, 1981, 1982; Rury & Dickison, 1984). man (pers. comm.). Although some problem However, the heterogeneous, neotropical sec­ groups are wood (and leaf) structurally uni­ tions Archerythroxylum and Rhabdophyllum form, specimens on hand of several erythroxy­ are ecologically widespread and include all fo­ lums within each group easily can be distin­ liage types and wood anatomical profiles ob­ guished on wood (and / or leaf) anatomical served pantropically within Erythroxylum (loc. grounds. As discussed in detail below, wood cit.). Several exceptional species of Archery­ anatomy may therefore support the recogni­ throxylum (e.g., E. amplifolium) and Rhabdo­ tion of additional distinct species, or alterna­ phyllum (e.g., E. squamatum) also constitute tively, ecotypes of widely distributed, poly­ wood and leaf structural intermediates, which morphic species. interconnect all taxa and plant structural pro­ Section Macrocalyx is uniformly mesomor­ files into a continuum (Rury, 1982; Rury & phic and unspecialised in qualitative xylem fea­ Dickison, 1984). A central phylogenetic posi­ tures, although the wood of E. lucidum has tion for Archerythroxylum and Rhabdophyl­ narrower vessels and is slightly more specialised lum is implied by their ecological and pheno­ than that of E. macrophyllum (Table I). Signi­ typic diversity, as well as by their wood and ficantly, E. lucidum typically has smaller leaves leaf structural similarities with each other, and may represent a xerophytic ecotype of E. smaller Ery throxylum sections, and the African macrophyllum (Plowman, pers. comm.). endemic genera Aneulophus, Nectaropetalum Section Rhabdophyllum is ecologically and and Pinacopodium. structurally diverse and requires the recogni­ Wood anatomy of Nectaropetalum zuluense tion of at least two species groups. The first falls entirely within the range of variation seen group includes evergreen, sclerophyllous plants in erythroxylums of the neotropical section with a primitively mesomorphic wood anatomy Rhabdophyllum, except for the presence of and silica grains in the rays. Wood anatomy of calcium oxalate crystals (Nectaropetalum zulu­ E. citrifolium is the most variable in this sec­ ense) instead of silica grains (evergreen Rhabdo­ tion and intergrades with that of most other phyllum species) in their otherwise identical, evergreen, sclerophyllous Rhabdophyllum spe­ mostly uniseriate rays (Figs. I, 2, 12, 19, 20). cies with ray silica (Table I; Figs. 1,2). Wood Young stem anatomy also is identical in Necta­ anatomy thus does not contradict Schulz' (1907) ropetalum and all species of Erythroxylum and Plowman's (pers. comm.) belief that E. (Stapf & Boodle, 1909; Metcalfe & Chalk, 1950; amazonicum, E. citrifolium and E. mucronatum Rury, 1981, 1982) and the striated stipules and are closely related (Figs. 18, 19). bud anatomy of Nectaropetalum kaessnerii Woods of the second Rhabdophyllum com­ from Africa are identical to those of evergreen plex contain calcium oxalate crystals in their Rhabdophyllum species in South America axial parenchyma and these species produce (Rury, loc. cit.). Foliage of Nectaropetalum either deciduous or evergreen, mostly sclereid­ species, several paleo tropical species of Ery­ free foliage. Although these plants form a wood throxylum and section Rhabdophyllum also is (and leaf) anatomical continuum along a de­ very similar in form, texture and venation, thus creasing moisture gradient (Table 3), from ever­ revealing parallel, evergreen-to-deciduous mor­ green mesophytes to deciduous xerophytes phological continua in both the Old and New (Rury, 1981, 1982; Rury & Dickison, 1984), World tropics (Rury, 1982; Rury & Dickison, their woods often can be distinguished (Table 1984). I; Figs. I, 2). Wood of E. deciduum is unique Infrageneric relationships within Erythroxy­ in its combination of: I) lack of inclusions; 2) lum were discussed only by Schulz (1907,1931), very wide and mostly solitary vessels; 3) large who established nineteen sections on the basis (6 - 8 ).Lm) intervessel pits; 4) high FL: VEL ra­ of stipular and floral morphology. Several of tio, and 5) very high VULN and MESO indices. Schulz' smaller Erythroxylum sections (e.g., Despite their similar diameters, vessels of E. Heterogyne and Macrocalyx) consist of species squama tum are much fewer and mostly solitary that are ecologically and wood anatomically in their distribution, while woods of E. raimon­ rather uniform, whereas the larger sections con­ dii and E. rufum are less easily distinguished tain species that are ecologically diverse with a due to their more subtle, habitat-related differ-

Downloaded from Brill.com10/03/2021 08:38:44PM via free access IAWA Bulletin n.s., Vol. 6 (4),1985 385 ences in pore density and distribution, and re­ Both varieties of E. novogranatense are lative tracheary element dimensions (Table I). drought tolerant and possess wider, fewer and Plowman's (pers. comm.) observation that a thicker-walled vessels with a more terete out­ related group of deciduous species of section line, shorter vessel elements, lower VEL: PDM Archerythroxylum reveal a morphocline from and higher FL: VEL ratios than in wood of E. the islands of the Caribbean to mainland Cen­ coca var. coca (Table I; Figs. 3, 4). Wood of tral and South America is corroborated by these Colombian (var. novogranatense) and wood anatomy. Qualitatively, the wood of E. Trujillo (var. truxillense) coca shrubs thus is brevipes, E. cumanense, and E. havanense is al­ more xeromorphically specialised, both in an most identical, but statistical data for vessel ecological and phylogenetic sense. Vessels of diameter and density reveals a series from the both E. novogranatense varieties are at least widest and fewest pores in E. cumanense, which 10% wider than those of E. coca var. coca also bears the thickest leaves (Rury, 1982), an (Table I), thus implying a 50% greater potential intermediate condition in E. brevipes, to the hydraulic conductivity (cf. Zimmermann, 1978, narrowest and most numerous vessels in E. ha­ 1982, 1983). vanense (Table I). The similar wood (and de­ Soil moisture presumably is not a limiting ciduous foliage) of these plants therefore can­ factor in the water relations of cultivated coca, not justify their recognition as distinct species. since E. coca var. coca is restricted to the pe­ Despite this ubiquitous clinal variation in rennially mesic and humid, east Andean mon­ Erythroxylum wood anatomy, several major tana, while both varieties of E. novogranatense groups of species of Erythroxylaceae are wood are grown under irrigation or with comparable anatomically discernible. Although beyond the human assistance (Plowman, 1979, 1984a, b; scope of the present, preliminary report, a pa­ Bohm et al., 1982). Preliminary studies of fo­ per on wood identification in the Erythroxyla­ liar transpiration in cultivated coca in Peru dur­ ceae will be prepared following the study of ing 1981 and 1982 (Rury, unpubl. data) indi­ additional specimens. cate higher transpiration rates in both E. novo­ granatense varieties than in E. coca var. coca. The cultivated cocas Although preliminary, these wood anatomical Wood anatomy of the cultivated cocas (E. and leaf transpirational data suggest higher coca var. coca: Bolivian coca; E. novogranatense peak conductivities in the transpiration stream var. novogranatense: Colombian coca; and E. of E. novogranatense varieties, as would be ex­ novogranatense var. truxillense: Peruvian or pected of irrigated plants in a hot, bright and Trujillo coca) is very similar to that of their dry desert environment. Extensive studies of wild relatives of the neotropical section Arch­ foliar structure and transpiration in relation to erythroxylum (Table I; Figs. 3, 4, 25, 26, 28), hydraulic architecture are needed to clarify the many of which also resemble cultivated coca in hydrovascular biology and ecophysiological their leaf structure (Rury, 1981, 1982). Wood adaptations of these cultivated coca varieties. of the recently described Amazonian coca (E. Irrespective of such ecophysiological consid­ coca var. ipadu Plowman) was not available for erations, the wood anatomical homogeneity of study. Fibres are almost identical among these the cultivated cocas and their nearest wild rela­ cultivated cocas, but their vessel systems differ, tives implies a mesic ancestry from which mod­ as might be expected among ecologically and ern varieties of E. coca and E. novogranatense leaf structurally distinct varieties of comparable have been derived via their chemical, genetic architectural form and stature. Wood of E. coca and leaf structural divergence in relation to var. coca from the perennially moist montana long-term human selection, isolation and culti­ of the eastern Andean slopes of Bolivia and vation within ecologically distinctive, South Peru is clearly more primitive and mesomorphic American habitats. The totality of plant anato­ than wood of either variety of E. novograna­ mical and biosystematic evidence thus favours tense. Wood of E. coca var. coca contains nar­ the hypothesis advanced by Plowman (1979, rower and more numerous, thinner walled ves­ 1984a, b) and Bohm et al. (1982) that E. coca sels with an angular outline, as well as the long­ var. coca is the most nearly ancestral of the est vessel elements, highest VEL: PDM and cultivated coca varieties. lowest FL: VEL ratios, as compared with either variety of E. novogranatense (Table I; Figs. 3, Interfamilial relationships 4). Plants of E. coca var. coca and var. ipadu The strongest phenetic affinities among the also bear the largest and most mesomorphic fo­ Erythroxylaceae and other families of the liage of all varieties and are very drought in­ Geraniales, Linales and Malpighiales appear tolerant (Plowman, 1979, 1984a, b; Rury, 1981, 1982; Rury & Plowman, 1984). (text continued on page 392)

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Figs. 7-10. Scanning electron micrographs of Erythroxylum woods. - 7: Tangential view of vessel inner wall and ray cells containing silica grains (arrows) in E. macrocnemium (Schunke 3904). - 8-10: Unusual wall sculpture with helical ridges of inner wall material in E. myrsinites (Uw 14227).

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Figs. 11-14. Scanning electron micrographs of woods of Erythroxylaceae. - II: Vessel-ray pitting of Erythroxylum cuneatum (MAD-SJRw 50411). - 12: Transverse section of Nectaropetalum zuluense (MAD-S JRw 32928), showing solitary vessels, thick-walled fibres and axial parenchyma. - 13 & 14: Transverse sections of Pinacopodium congolense (FHOw 18268), showing thin-walled vessels with angular outline and unilaterally abaxial parenchyma associated with vessels (arrows).

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Legends to Figures 15-40:

Figs. 15-23. Photomicrographs of Ery throxylum species belonging to section Macrocalyx (15-17) and section Rhabdophyllum (18-23). - 15: E. macrocnemium (MADw 28835), showing primitive­ ly mesomorphic wood with thin-walled vessels with an angular outline and fibres with walls of medium thickness. - 16: Ibid. (Plowman 5800), tangential view of wood showing uniseriate and biseriate rays, axial parenchyma and libriform fibres. - 17: E. macrophyllum (Uw 1828), transec­ tion showing combination of wide, solitary and radial multiples of vessels. - 18: E. amazonicum (Uw 4986), showing broad expanse of latewood with few vessels and sharp transition to numerous early wood vessels. - 19: E. citrifolium (Uw 4215), showing combination of solitary pores and radial multiples. - 20: E. campinense (Prance 18722; isotype), showing predominance of solitary vessels and sparse parenchyma amidst thick-walled libriform fibres. - 21: E. raimondii (Aw 30670), showing predominance of thick-walled vessels in long radial mUltiples. - 22: E. squama tum (Uw 4719), showing thick-walled vessels with a mostly solitary distribution. - 23: E. steyermarkii (Plowman 7800; isotype), one of the rare wood samples in which both ray-silica (large arrows) and axial-prismatic crystals (small arrows) occur in their normal locations. - All scale bars 50 Jl.m.

Figs. 24-32. Photomicrographs of Erythroxylum species belonging to section Heterogyne (24) and section Archerythroxylum (25-32). - 24: E. areola tum (Aw 21266), showing thin-walled vessels arranged singly and in radial multiples, and rather abundant, paratracheal axial parenchyma. - 25 & 26: E. cuatrecasasii (Cuatrecasas 15736; isotype), transverse and tangential sections, showing thin, rather angular vessel walls, solitary and radial multiple vessel arrangement, abundant para tracheal and abaxially confluent parenchyma and (26) biseriate rays with square and erect marginal ('wing') cells. - 27: E. kapplerianum (Uw 21771), transverse section through a growth increment, showing solitary, thick-walled vessels, in a nearly semi-ring-porous distribution. - 28: E. lineolatum (Broad­ way 6054), showing a combination of solitary vessels and short radial multiples. - 29: E. mamacoca (Plowman 5959), showing a predominance of rather narrow, solitary pores and sparse parenchyma. - 30: E. mexicanum (MAD-SJRw 2947), showing solitary pores and radial multiples, abundant para­ tracheal parenchyma and thick-walled libriform fibres. - 31: E. pacificum (Plowman 5520), show­ ing growth increments near pith (bottom) and a pore distribution that approaches the semi-ring­ porous condition. - 32: E. williamsii (Plowman 7730; isotype), showing junction of two growth increments (near bottom) and both solitary vessels and radial multiples, as well as very thick-walled, libriform fibres and rather thick vessel walls. - All scale bars 50 Jl.m.

Figs. 33-40. Photomicrographs of wood of paleotropical species of Erythroxylum (33-39) and a scanning electron micrograph of the wood of Pinacopodium (40). - 33: E. delagoense (MAD-SJRw 32268), showing junction of two growth increments (arrows) and vessels distributed singly and in radial multiples. - 34: E. mannii (RBHw 8152), showing very wide, thin-walled vessels, rather thin­ walled libriform fibres and extreme paucity of axial parenchyma. - 35: Ibid. (Kw s.n. # 10), tangen­ tial view showing three vessel elements with nearly transverse perforation plates and both uniseriate and biseriate rays. - 36 & 37: E. monogynum (MAD-SJRw 3816), showing solitary pores and ra­ dial mUltiples, abundant and darkly stained (oils?) axial parenchyma, predominantly biseriate rays, axial parenchyma with prismatic crystals (arrows) and a vessel with nearly transverse end walls con­ taining two very thin-walled tyloses. - 38: E. cuneatum (MADw 22225), showing mesomorphically specialised wood with wide, thin-walled vessels occurring singly and in short radial multiples, as well as sparse, apotracheal and paratracheal parenchyma. - 39: E. hypericifolium (Aw 21258), showing very wide, thin-walled, exclusively solitary vessels, thick-walled libriform fibres and abundant, apo­ tracheal and paratracheal, banded parenchyma. - 40: Pinacopodium congolense (FHOw 18268), scanning electron micrograph of radial section showing prismatic crystals of calcium oxalate in pro­ cumbent and square, marginal ray cells. Note that the wood of Nectaropetalum zuluense shares this unique characteristic also, whereas ray cells of Erythroxylum either lack crystals entirely or contain only silica grains. - All scale bars 50 Jl.ffi.

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among the seemingly most primitive and meso­ ever, are more advanced than woods of Cteno­ morphic taxa within each family (Metcalfe & lophon. Humiriaceae and , with ex­ Chalk, 1950; Rury, 1982). Taxa of Humiria­ clusively simple vessel perforations (Metcalfe & ceae, Ixonanthaceae and Malpighiaceae often Chalk, 1950; Rury, 1982). occur in the same or similar habitats as mem­ Wood of Humiriaceae is more primitive than bers of Erythroxylaceae (e.g., Badre, 1972; Ben­ that of most Linaceae (Metcalfe & Chalk, 1950) tham, 1863; Corner, 1952; Cuatrecasas, 1961; and all genera of Erythroxylaceae (Rury, 1982), Eiten, 1972; Evrard, 1957; Exell & Mendonya, and its extremely long, solitary vessel elements 1951; Gentry, 1975; Goldblatt, 1978; Heyligers, with many barred (15-25) scalariform perfora­ 1963; Leonard, 1950; Leroy, 1978; Macedo & tions imply a mesic familial ancestry (Baas, Prance, 1978; Mori et aI., 1983; Palmer & Pit­ 1982; Carlquist, 1975, 1980; Dickison et aI., man, 1972 and Prance, 1978). Primitively me­ 1978). Scalariform vessel perforations are very somorphic taxa of Erythroxylaceae, such as rare in the Erythroxylaceae. They appear only Aneulophus, Pinacopodium and several ery­ sporadically in the metaxylem or early second­ throxylums of the neotropical section Rhabdo­ ary xylem of a few specimens and are best phyllum, share various morphological, anatomi­ regarded as primitive within the Geraniales­ cal and reproductive features in common with Linales-Malpighiales. one or more genera of various families in the Genera of Linaceae are wood anatomically Geranialean-Linalean-Malpighealean complex quite variable, as reflected in the presence of: (Metcalfe & Chalk, 1950, Narayana & Rao, 1) solitary vessels or radial vessel multiples; 2) 1978; Rury, 1982). The presumably basal ele­ scalariform or simple vessel perforations; 3) ments of each family are uniformly mesomor­ small, bordered to large, simple vessel-ray pit­ phic in their vegetative morphology, with: 1) ting; and 4) diffuse to banded, apotracheal large, evergreen and rather coriaceous leaves; axial parenchyma (Metcalfe & Chalk, 1950; 2) conspicuous 'drip tip' leaf apices, and 3) Baas, pers. comm., 1984). Wood anatomical uniformly stout, regular, camptodromous leaf heterogeneity in the Linaceae presumably re­ venation with good resolution of successive flects, at least in part, its wide range of life vein orders and well-developed areolation. This forms, including herbs, lianas, shrubs and trees shoot morphology is characteristic of Ctenolo­ of various sizes (Cronquist, 1968, 1981; Hut­ phon Oliv., Ixonanthes Jack. Lepidobotrys Engl. chinson, 1973; Takhtajan, 1969); indeed, Van and Saccoglottis End!., and the erythroxylace­ Welzen and Baas (1984) noted a correlation be­ ous taxa Aneulophus, Nectaropetalum, Pinaco­ tween leaf structure and plant habit within the podium and Erythroxylum sections Archery­ Linaceae. Nevertheless, the wide range of wood throxylum, Megalophyllum and Rhabdophyl­ anatomical variation within the Linaceae is to­ lum (loc. cit.; cf. Rury, 1982). These taxa also tally inclusive of that in the Humiriaceae, Cte­ possess the evolutionarily least specialised nolophon (Metcalfe & Chalk, 1950) and Ery­ wood anatomy within their respective families, throxylaceae (Rury, 1982). as is discussed in detail below. Wood anatomical features shared by the Ery­ Ctenolophonaceae is a monogeneric family throxylaceae (Rury, 1982) and Malpighiaceae (sensu Hutchinson, 1973) which sometimes is (Metcalfe & Chalk, 1950) include: I) simple merged with the Linaceae (Metcalfe & Chalk, vessel perforations; 2) radial pore multiples; 3) 1950; Erdtman, 1952; Narayana & Rao, 1978) similar intervessel and vessel-ray pitting; 4) di­ or Hugoniaceae (Cronquist, 1981). Metcalfe and verse but fundamentally similar patterns of Chalk noted that Ctenolophon wood is more axial parenchyma distribution, and 5) 2-3- primitive than that of most Linaceae and ap­ seriate, heterocellular rays. Phenetic affinities proaches the lower level of evolutionary spe­ among Nectaropetalum. Pinacopodium. Cteno­ cialisation found in the Humiriaceae. Wood of lophon, Humiriaceae and Malpighiaceae also Ctenolophon resembles that of Nectaropetalum are implied by their shared development of and Pinacopodium in general aspect, except for nearly homocellular, 1-2-seriate wood rays, the scalariform vessel perforations in Ctenolo­ with chambered, prismatic crystals in the ray phon, with up to 25 bars per plate (Metcalfe & cells, and predominantly small, bordered, vessel­ Chalk, 1950; Rury, 1982). These three genera ray pitting (Metcalfe & Chalk, 1950; Rury, and the more primitive genera of Linaceae 1982). Although overall variation may be more (sensu lato) such as Hebepetalum Benth., Ixo­ extensive in the much larger family Malpighia­ nanthes and Lepidobotrys, also share similar ceae, even the statistical details of xylem struc­ uni- to biseriate rays, often with calcium oxalate ture are very similar in the Erythroxylaceae prismatic crystals (Metcalfe & Chalk, loc. cit.; and Malpighiaceae. Normand & Cavayo, 1951). Erythroxylum. Nec­ Recent evidence from comparative leaf anat­ taropetalum and Pinacopodium woods, how- omy of the Linaceae complex (Linaceae S.S.,

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Hugoniaceae, Ixonanthaceae, Humiriaceae and wood specimens. Dr. Plowman's extensive, first­ Erythroxylaceae), Ctenolophon and Lepidobo­ hand knowledge of Erythroxylum trys have clarified the probable evolutionary re­ and ecology was a major factor contributing to lationships among these taxa (Van Welzen & the comprehensive scope and ecosystematic Baas, 1984). These authors noted that the 'six tone of this research. Linaceae genera form a leaf anatomically co­ The assistance of staff members at various herent group' and although both the Humiria­ herbaria (A, B, BR, COL, DUKE, ECON, F, ceae and Ixonanthaceae are leaf anatomically FHO, GH, HBG, INCA, K, M, MO, NCU, NY, diverse, available evidence fully supports pre­ P, PSO, U, US, USM) and xylaria (Aw, Bw, sumed affinities among these three families and FHOw, Kw, MAD-SJRw, RBHw, Uw, USw) the Erythroxylaceae. They also supported who provided specimens for study also is ap­ Cronquist's (1981) removal of the Humiriaceae preciated. This research was supported, in part, from the Linaceae and his recognition of the by the William C. Coker Fellowship and Smith Hugoniaceae and Ixonanthaceae as separate Fund for doctoral dissertation improvement of families, noting that 'the Hugoniaceae are leaf the University of North Carolina at Chapel Hill. anatomically the most distinct and coherent Postdoctoral field studies of foliar transpiration group of the Linaceae complex and differ more in Peruvian Erythroxylum species were sup­ from the Linaceae s. s. than the latter do from ported by the Katharine W. Atkins Fund of the Erythroxylaceae and Humiriaceae.' Van Harvard University. I also wish to thank the of­ Welzen and Baas (loc. cit.) also concluded that ficials of the Empresa Nacional de la Coca 'leaf anatomy favours exclusion of Ctenolo­ (Lima) for their kind cooperation in providing phon from this alliance', and that although 'Le­ access to commercial coca plantations. pidobotryaceae cannot be excluded .... on ac­ Special thanks are due to Pieter Baas, Sherwin count of its leaf anatomy', they do not object Carlquist, Bill Dickison, Regis Miller and Tim on anatomical grounds to Cronquist's (1981) Plowman for their helpful comments and con­ placement of it within the Geraniales together structive criticism of this manuscript. The assis­ with the . tance of Ms. Dotty Smith in manuscript prepa­ Published anatomical evidence for the fami­ ration also is very much appreciated. lies discussed above, and data presented by Rury (1981, 1982) for leaf and reproductive mor­ phology of the Erythroxylaceae, fully support References the following opinions of Cronquist (1968, Amos, G.L. 1951. Some siliceous timbers of 1981), Narayana and Rao (1978), and Oltmann British Guiana. Caribbean For. 12: 133- (1968): 1) the Humiriaceae, Linaceae and Ery­ 137. throxylaceae are closely related and were prob­ - 1952. Silica in timbers. CSIRO Bull. 267. ably derived from a common, extinct ancestral Baas, P. 1973. The wood anatomical range in taxon; 2) these three families combine similari­ Ilex and its ecological and phylogenetic sig­ ties which reflect common ancestry and differ­ nificance. Blumea 21: 193-258. ences that warrant their familial distinction; 3) - 1976. Some functional and adaptive aspects the Humiriaceae are more primitive than either of vessel member morphology. In: Wood Linaceae or Erythroxylaceae, and 4) the Ery­ structure in biological and technological re­ throxylaceae have evolved along a distinct and search (eds. P. Baas, A.I. Bolton & D.M. Cat­ divergent line, in comparison with the Humiria­ ling): 157-181. Leiden Bot. Ser. 3. Leiden ceae and Linaceae. Wood anatomical data pre­ Univ. Press. sented here for the Erythroxylaceae, however, - 1982. Systematic, phylogenetic and ecolog­ neither affirm nor cast doubt upon these inter­ ical wood anatomy. History and perspec­ familial phylogenetic conclusions. tives. In: New perspectives in wood anatomy (ed. P. Baas): 23-58. Nijhoff/Junk Publ., Acknowledgements The Hague. This study is based in part on a doctoral dis­ - , E. Werker & A. Fahn. 1983. Some ecologi­ sertation submitted to the Graduate School of cal trends in vessel characters. IAWA Bull. the University of North Carolina at Chapel Hill. n.s.4: 141-159. I am indebted to my doctoral adviser, Dr. William Badre, F. 1972. Erythroxylaceae. In: Flore du C. Dickison for guidance during this research. I Cameroun (eds. A. Aubreville & J.F. Leroy): also am immeasurably grateful to Dr. Timothy vol. 14: 51...,.56. Mus. Nat. Hist. Nat. Paris. Plowman (Field Museum of Natural History, Bailey, I. W. 1957. The potentialities and limi­ Chicago) for his perennial encouragement, pain­ tations of wood anatomy in the study of staking collaboration and help in acquiring and phylogeny and classification of angiosperms. identifying herbarium vouchers for neotropical J. Am. Arbor. 38: 243-254.

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Bentham, G. 1863. Linaceae. In: Flora Austra­ Czaninski, Y. 1977. Vessel- associated cells. liensis 1: 283-284 (Erythroxylon in the IAWA Bull. 1977/3: 51-55. Lineae). Dickison, W.C. 1975. The bases of angiosperm Bohm, B.A., F.R.Ganders & T. Plowman. 1982. phylogeny: vegetative anatomy. Ann. Mis­ Biosystematics and evolution of cultivated souri Bot. Gard. 62: 590-620. coca. Syst. Bot. 7: 121-133. - 1980. Comparative wood anatomy and evo­ Browne, P. 1756. Civil and natural history of lution of the Cunoniaceae. Allertonia 2: Jamaica. London. p. 278. 281-321. Carlquist, S. 1966. Wood anatomy of the Com­ - , P.M. Rury & G.L. Stebbins. 1978. Xylem positae: a summary with comments on the anatomy of Hibbertia (Dilleniaceae) in rela­ factors controlling wood evolution. Aliso tion to ecology and evolution. J. Am. Arbor. 6: 25-44. 59: 32-49. - 1975. Ecological strategies of xylem evolu­ Eiten, G. 1972. The cerrado vegetation of Bra­ tion. Univ. Calif. Press, Los Angeles. zil. Bot. Rev. 38: 201-341. - 1977. Ecological factors in wood evolution: Erdtman, G. 1952. Pollen morphology and a floristic approach. Amer. J. Bot. 64: 887- plant taxonomy. Angiosperms. Almquist & 896. Wiksell, Uppsala. - 1980. Further concepts in ecological wood Evrard, C.1957. L'Association Aneulophus afri­ anatomy, with comments on recent work canus Benth. Foret periodiquement inondee in wood anatomy and evolution. Aliso 9: sur podzol humique au Congo Beige. Bull. 499-553. Jard. Bot. Brux. 27: 335-349. - & L. DeBuhr. 1977. Wood anatomy of Pe­ Exell, A.W. & F.L. Mendonya. 1951. Nectaro­ naeaceae (Myrtales): comparative, phylo­ petalaceae. In: Conspectus Florae Angolen­ genetic and ecological implications. Bot. J. sis 1: 246. Lisboa. Linn. Soc. 75: 211-227. Ferri, M.G. 1953. Water balance of plants from Chalk, L. 1938. Standardization of terms for the 'Caatinga'. II. Further information on vessel diameter and ray width. Trop. Woods transpiration and stomatal behavior. Rev. 55: 16-23. Brasil. BioI. 13: 237-244. - & M.M. Chattaway. 1935. Factors affecting - & L.G. Labouriau. 1952. Water balance of dimensional variations of vessel members. plants from the 'Caatinga'. I. Transpiration Trop. Woods 41: 17-36. of some of the most frequent species of the Chattaway, M.M. 1932. Proposed standards for 'caatinga' of Paulo Afonso (Bahia) in the numerical values used in describing woods. rainy season. Rev. Brasil. BioI. 12: 301-312. Trop. Woods 29: 20-28. Gentry, A.H. 1975. Humiriaceae. In: Flora of Committee, I.A.W.A.1981. Standard list of char­ Panama, Part VI (eds. R.E. Woodson et al.). acters suitable for computerized hardwood Ann. Missouri Bot. Gard. 62: 35-44. identification. IAWA Bull. n.s. 2: 99-110. Goldblatt, P. 1978. An analysis of the flora of Committee on Nomenclature, I.A.W.A. 1964. Southern Africa: its characteristics, relation­ Multilingual glossary of terms used in wood ships and origins. Ann. Missouri Bot. Gard. anatomy. Konkordia, Winterthur. 65: 369-436. Committee on the Standardization of Terms of Graaff, N. A. van der & P. Baas. 1974. Wood Cell Size, I.A.W.A. 1937. Standard terms of anatomical variation in relation to latitude length of vessel members and wood fibers. and altitude. Blumea 22: 101-121. Trop. Woods 51: 21. Gregory, R.A. 1978. Living elements of the Corner, E.I.H. 1952. Wayside trees of Malaya. conductive secondary xylem of sugar maple Govt. Printer, Singapore. (Acer saccharum Marsh.).IAWA Bull. 1978/ Coutinho, L.M. & M.G. Ferri. 1956. Transpira­ 4: 65-69. "ao de plantas permanentes do cerrado no Heyligers, P.e. 1963. Vegetation and soil of a Esta"ao das Chuvas. Rev. Brasil. BioI. 16: white-sand savanna in Suriname. Noord­ 501-518. Hollandsche Uitg. Mij., Amsterdam. Cronquist, A. 1968. The evolution and classifi­ Holmgren, P. K. & W. Keuken. 1974. Index Her­ cation of flowering plants. Houghton Mifflin bariorum. 6th Ed. Oosthoek, Scheltema & Co., Boston. Holkema, Utrecht. - 1981. An integrated system of classifica­ Hutchinson, 1.1967. Genera of flowering plants. tion of flowering plants. Columbia Univ. Vol. II. Clarendon Press, Oxford. Press, N.Y. - 1969. Evolution and phylogeny of flower­ Cuatrecasas, 1. A. 1961. A taxonomic revision ing plants. Acad. Press, London. of the Humiriaceae. Contr. U. S. Nat. Herb. - 1973. The families of flowering plants. 3rd 35: 25-214. Ed. Clarendon Press, Oxford.

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Kramer, P.J. & T.T. Kozlowski. 1979. Physiol­ Oltmann, O. 1968. Die Pollenmorphologie der ogy of woody plants. Acad. Press, New York. Erythroxylaceae und ihre systematische Be­ Kribs, D.A. 1935. Salient lines of structural deutung. Ber. Deutsch. Bot. Ges. 81: 505- specialization in the wood rays of dicotyle­ 511. dons. Bot. Gaz. 96: 547- 557. Palmer, E. & N. Pitman. 1972. The trees of Larson, P. R. 1964. Some indirect effects of en­ Southern Africa. Vol. 2: 963- 969. A.A. vironment on wood formation. In: The for­ Balkema, Capetown. mation of wood in forest trees (ed. M.H. Payens, J.P.D.W. 1958. Erythroxylaceae. In: Zimmermann): 345-365. Acad. Press, New Flora Malesiana (ed. C.G.GJ. van Steenis) York. I, 5: 543-552. Noordhoff, Groningen. Leonard, J. 1950. . Bull. J ard. Plowman, T. 1976. Orthography of Erythroxy­ Bot. Etat Brux. 20: 31-40. lum (Erythroxylaceae). Taxon 25 : 141 - Leroy, J.F. 1978. Composition, origin and af­ 144. finities of the Madagascan vascular flora. - 1979. Botanical perspectives on Coca. J. Ann. Missouri Bot. Gard. 65: 535- 589. Psychedelic Drugs II: 103-117. Lewin, J. & J. Reimann. 1969. Silicon and plant - 1982. The identification of Coca (Ery­ growth. Ann. Rev. PI. Physiol. 20: 289-304. throxylum species): 1860- 1910. Bot. J. Linnaeus, C. von. 1759. Systema Naturae. Stock­ Linn. Soc. 84: 329- 353. holm. - 1984a. The ethnobotany of Coca (Ery­ Macedo, M. & G. T. Prance. 1978. Notes on the throxylum spp., Erythroxylaceae). In: vegetation of Amazonia. II. The dispersal Ethnobotany in the Neotropics (eds. G. T. of plants in Amazonian white sand campi­ Prance & J.A. Kallunki): Vol. 1. Advances nas: the campinas as functional islands. Brit­ in Economic Botany. tonia 30: 203-215. - 1984b. The origin, evolution and diffusion Machado, E.C. 1972. EI genero Erythroxylon of Coca (Erythroxylum spp.) in South and en el Peru. Raymondiana 5: 5- 101. Central America. In : Pre-Columbian plant Martius, Ph. von. 1843. Beitrage zur Kenntnis migration (ed. D. Stone). Pap. Peabody Mus. der Gattung Erythroxylon. Abh. Miinch. Archaeol. & Ethnol. 76: 125- 163 . Harvard Akad. (math.-phys. Kl.) III (2): 283- 410. Univ., Cambridge, Mass. Melchior, H. 1964. Erythroxylaceae. In: Sylla­ Prance, G. T. 1978. The origin and evolution of bus der Pflanzenfamilien II (ed. A. Engler). the Amazon flora. Interciencia 3: 207-222. Gebr. Borntraeger, Berlin. Quirk, 1. T. 1980. Wood anatomy of the Vochy­ Metcalfe, C.R. & L. Chalk. 1950. Anatomy of siaceae. IAWA Bull. n.s. I: 172- 179. the Dicotyledons. Vol. 2: 268-285. Claren­ Raunkiaer, C. 1934. The life forms of plants and don Press, Oxford. statistical plant geography. Clarendon Press, Michener, D.C. 1981. Wood anatomy of Keck­ Oxford. iella (Scrophulariaceae): ecological consid­ Rawitscher, F. 1948. The water economy of the erations. Aliso 10: 39- 57. vegetation of the ' Campos Cerrados' in Miller, R. B. 1981. Explanation of coding pro­ Southern Brilzil. J. Ecol. 36: 237- 268. cedure (for IAWA Standard List of Charac­ Reiche, K. von. 1896. Erythroxylaceae. In: Die ters suitable for Computerized Hardwood natiirlichen Pflanzenfamilien (eds. A. Engler Identification). IAWA Bull. n.S. 2: 111 - & K. Prantl). 2nd Ed. Vol. 3 (4): 37- 40. 145. Leipzig. Mori, S.A., B.M. Boom, A.M. de Carvalho & Rury, P.M. 1981. Systematic anatomy of Ery­ T.S. dos Santos. 1983. Southern Bahian throxylum P. Browne: Practical and evolu­ moist forests. Bot. Rev. 49: 155 - 232. tionary implications for the cultivated Narayana, L.L. & D. Rao. 1978. Systematic cocas. J. Ethnopharm. 3: 229- 264. position of Humiriaceae, Linaceae & Ery­ - 1982. Systematic anatomy of the Erythro­ throxylaceae in light of their comparative xylaceae. Unpubl. Ph.D. Thesis. Univ. of floral morphology and embryology. A dis­ North Carolina at Chapel Hill. xvi & 461 pp. cussion. J. Indian Bot. Soc. 57 : 258- 266. - & W.C. Dickison. 1984. Structural correla­ Normand, D. & A. Cavayo. 1951. Observations tions among wood, leaves and plant habit. taxonomiques et xylogiques sur Ie genre In : Contemporary problems in plant anato­ Pinacopodium Exell & Mendonya. Bull. my (eds. R. A. White & W. C. Dickison). Jard. Bot. Etat Brux. 20: 451 - 463. Acad. Press, New York. Oever, L. van den , P. Baas & M. Zandee. 1981. - & T. Plowman. 1984. Comparative mor­ Comparative wood anatomy of Symplocos phological studies of archeological and and latitude and altitude of provenance. modern coca leaves (Erythroxylum spp.). IAWA Bull. n.s. 2: 3- 24. Harvard Bot. Mus. Leafl. 29: 297-341.

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APPENDIX 1

Ecological preferences, plant habit maxima, leaf duration and leaf size-class maxima for neotropical species of Erythroxylum represented in Tables 1-3.

Section & ECOL I HABIT2 LDUR 3 LSMX 4 Species

Macrocalyx E.lucidum SX-M 15 m Evgn 4 E. macrocnemium M 10 m Evgn 5 E. macrophyllum M 12 m Evgn 5 E. suberosum X 3m Evgn 4 Rhabdophyllum E. amazonicum M 30m Evgn 4 E. amplum M 4m Evgn 5 E. campinense SX-M 1m Evgn 3 E. citrifolium SX-M 10m Evgn 4 E. deciduum SX-X 6m Decd 4 E. fimbria tum M 5m Evgn 4 E. mucronatum M (20 m) Evgn 4 E. myrsinites M 3m Evgn 3 E. raimondii SX 2m Decd 4 E. rufum SX 9m Decd 4 E. squama tum M (9 m) Evgn 4 E. steyermarkii SX (5 m) Decd 4 Leptogramme E. pulchrum M 9m Evgn 4 E. ulei M 4m Evgn 4

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Section & ECOL' HABIP LDUR 3 LSMX' Species

Heterogyne E. areola tum SX-M 6m Decd 4 E. minutifolium SX-X 1m Evgn 2 E. rotundifolium SX-M 8m Evgn 3 Archerythroxylum E. amplifolium M 2m Evgn 3 E. argentinum SX (4 m) Decd 4 E. brevipes SX 4m Decd 3 E. carthagenense X-SX 5m Decd 4 E. cataractarum SX-M 3m Evgn 3 E. coca M 3m Evgn 4 E. confusum SX-M 9m Decd 4 E. cuatrecasasii M (8 m) Evgn 4 E. cumanense SX (4 m) Decd 4 E. densum SX 4m Decd 3 E. glaucum SX 4m Decd 3 E. haughtii SX 7m Decd 4 E. havanense SX 6m Decd 4 E. kapplerianum M 5m Evgn 4 E. lineolatum SX-M 00 m) Evgn 4 E. mamacoca M 13m Evgn 4 E. mexicanum SX Decd 3 E. novogranatense SX 3m Evgn 3(-4) E. novogranatense var. truxillense SX 3m Evgn 3(-4) E. orinocense SX 7m Decd 4 E. pacificum SX 20m Evgn 3(-4) E. shatona M 12m Evgn 4 E. undulatum SX 3m Decd 3 E. vernicosum M 5m Evgn 3(-4) Microphyllum E. cuneifolium X-SX 3m Evgn 3 E. microphyllum X 0.6m Evgn 2 E. panamense M 2m Evgn 4

, Ecological preferences (sensu Plowman): M = mesic, more or less continuously moist forest; SX = semi-xeric, more or less seasonally moist forest; X = xeric, dry to seasonal, more or less open fonnations.

2 Habit maxima: from literature; or directly from specimens examined, value in parentheses; expressed in metres.

3 Leaf duration: evergreen vs. deciduous.

• Leaf size class maximum (sensu Raunkiaer, 1934): 2 = 25-225 sq.mm; 3 = 225-2,025 sq.mm; 4 = 2,025-18,225 sq.mm; 5 = 18,225-164,025 sq.mm total leaf surface area.

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