First Description of the Wood Anatomy of Antrophora, Lepidocordia and Pteleocarpa (Boraginaceae)

IAWA Bulletin n.s., Vol. 3 (3-4), 1982 161

FIRST DESCRIPTION OF THE WOOD ANATOMY OF ANTROPHORA, LEPIDOCORDIA AND PTELEOCARPA (BORAGINACEAE)

H. Gottwald Institut für Holzbiologie und Holzschutz der Bundesforschungsanstalt für Forst- und Holzwirtschaft, Leuschnerstrasse 91d, 0-2050 Hamburg 80, Federal Republic ofGermany

Summary The secondary xylem of three uncommon liams & Mollina, US 42417 (RBHw 17484), genera of Boraginaceae was studied anatomical branch, 0.5 mm in diameter. ~ Lepidocordia Iy and compared to other taxa of this and oth punctata Ducke: Venezuela, Bernardi 7425 er families. The two neotropical genera Antro (RBHw 16674 ex MERw 3280) and Bernardi phora and Lepidocordia are similar in their 7373 (RBHw 17218 ex CTFw 23744). - wood anatomy and show only limited resem Pteleocarpa lamponga (Miq.) Bakh.: Sarawak blance with the subfamily Ehretioideae. On the (RBHw 16499 ex SARFw 15533); Indonesia, other hand, the old world genus Pteleocarpa v.d. Koppel s.n. (RBHw 17525 ex SJRw 15470). shows hardly any affinity to Boraginaceae. Quantitative data represent the averages of Two of the genera reveal xylem features which both sampIes investigated per species. With re are unique within Boraginaceae, and which are gard to length of the fibres and fibre-traeheids matched by an equally unique flower morphol the 10west and the highest value of the sampIe ogy. pair is given as weil as the average value of both sam pies, e.g. 200-1400-2000 pm (150 mea Introduction surements each). General information on the wood structure The values for specifie gravity are based on of the family Boraginaceae is for the most part oven-plants. Only the Ehretioideae. Distribution: Nicaragua (endem small genera Auxemma, Patagonula and Saccel ie), dept. Matagalpa, 750 m alt. Habit: trees to /ium (Record & Hess, 1941) and Echium (Carl 10 m tall with stern diameters up to 0.5 m. quist, 1970) are weil documented. Information Mieroseopic features (Fig. 1&2): concerning the wood structure of taxa from Vessels round to oval in cross section, often the subfamily Ehretioideae is particularly scan radially grouped, diameter 50-60 J.lm; walls ty. For this reason, and because of their iso 2.5 J.lm thick; perforations always simple, end lated position within Boraginaceae with regard walls oblique (40 ° -60°); pits round, alternate to flower morphology, a microanatomical anal and vestured, diameter 2.5 J.lm, c10sely spaced ysis of the secondary xylem of the little known (30 per 500 J.lill2). Rayshomogeneous; uni- and genera Antrophora, Lepidocordia, and Pteleo biseriate, and 8 to 10 cells high, cell walls 2-3 carpa is presented here for the first time. J.lm thick; pits to vessels similar to intervessel A survey of the wood anatomy of the whole pits. Parenchyma moderately abundant; apo family is in progress (Gottwald, in preparation). tracheal with uniseriate short bands or diffuse; cell diameter 15 J.lm; occasionally chambered Material and Methods with rhombic crystals. Fibre-tracheids poly All the sam pIes (6) are backed by herbarium gonal;diameter 10-15 J.lm, walls 3-4 J.lm thick; material and were obtained from wood collec pits finely bordered, unevenly distributed, dia tions of various institutions (cited according to meter 3-4 J.lm. Tracheids adjacent to vessels, Stern, 1978): very rare; diameter 15-20 J.lm, walls 4 J.lm Antrophora williamsii LJ. Johnston: Nicara thick; pits uni- to triseriate, diameter 3 J.lm ves gua, Williams & Mollina, A 10960-Type (RBHw tured. Growth boundaries slightly marked by 17489), branch, 0.4 mm in diameter, and Wil- different size and frequeney of vessels.

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Notwithstanding the juvenile state of the gum-like deposits; pits to vessels similar to in sampies, sufficient taxonomically important tervessel pits. Parenchyma abundant, apotra features are in evidence. The organisation and cheal, mostly in uniseriate bands, alm ost reticu distribution of vessels, constitution of rays and late, cells partly in short aggregates or solitary; morphology of fibres combine to a picture that cell diameter 12-15 f.Lill; often in axial strands indicates a slightly advanced rather than primi of four cells, 350-400 f.Lm long; walls about tive structure. Of particular interest within this 1-1.5 f.Lm thick; often with chambered rhom structural concept is the minute size of vestur boidal crystals or light brown gum-like deposits. ed intervessel pits equivalent to the minimum Fibre-tracheids angular; diameter 15-20 f.Lm, diameter so far known for intervascular pits in walls 4-5 f.Lm thick, length 300-965-1600 woody plants. (For comparison see under Lepi f.Lm; pits finely bordered, unevenly distributed, docordia). diameter 3-4 f.Lm. Tracheids present adjacent to vessels, rare; diameter 30-35 f.Lm, length 600-700-750 p.m, walls 4 f.Lm thick; pits one Lepidocordia Ducke in Arch. Jard. Bot. Rio Ja- to triseriate, vestured, diameter 2.5 -3 f.Lm. neiro 4: 170-172 (1925). Monotypic genus. Lepidocordia is characterised by a weil de Lepidocordia punctata Ducke, subfamily Ehre fined radial orientation of the vessels, storied tioideae. Distribution: Brazil (Para); Guyana; rays and by extremely fine vessel pits. The spo Venezuela; 90-150 m alt. (Ducke, 1925; John radic occurrence of tracheids with pits similar ston, 1935; Aristeguieta, 1973). Habit: trees to to those between the vessels is matched by 30 m tall with heavily fluted sterns of diameters other wood species with an equally high inci up to 0.6 m. Local names: Guatacare negro dence of vessels. Hence the wood structure of (Venezuela). this species (genus) is to be considered at a sim General features: ilar phylogenetic advancement as that of the Wood nearly even-coloured, yellowish to genus Antrophora. light brown and dense textured. Pores only visi ble with the naked eye at clean cross sections as light and radially oriented fields. Rays faint Pteleocarpa Oliver in Trans. Linn. Soc. 28: 515 as tiny flecks (radial), storied, forming ripple (1873). Monotypic genus. marks (tangential). Growth boundaries mostly Pteleocarpa lamponga (Miq.) Bakh. ex Heyne visible as wavy lines. Timber of unattractive ap in Nutt. PI. Ned. Ind. ed. 2: 1309 (1927) (Do pearance and medium to heavy weight (0.85 donaea ? lamponga Miq. in F!. Ind. Bat. Supp!.: g/cm3), almost of the boxwood type. 511. 1860). Local names: Dangkoe, Kihoelat Microscopic features (Figs.3-7): talang, Madang, Sago, Solgi-soegi. Distribution: Vessels round to oval in cross section, clus Malaysia (Sarawak); Indonesia (South and West tered and concentrated in long radial to almost Sumatra). Habit: trees to 35 m tall, sterns weil flame-like fields; diameter 55-65 f.Lm, walls 3 formed with diameters about 0.5 m (Endert, f.Lm thick; perforations always simple, end walls 1925; Heyne, 1927). strongly oblique; pits alternate, round and ves General features: tured, diameter 2.5-3 f.Lm; closely spaced (33 Evenly coloured, yellowish to light brown. per 500 f.Lm 2). Rays homogeneous, mostly bi-, Pores visible with a lens at clean cross sections. partly triseriate and 12-15 cells high (= 230- Unattractive, straight-grained timber; specific 280 f.Lm); storied (3/mm); often with brownish gravity 0.7-0.78 gjcm3 .

Fig. 1 & 2. Antrophora williamsii, x 110. - I: Cross section: vesselsin radial groups; parenchyma apotracheally diffuse or in uniseriate aggregates. - 2: Tangential section: vessels with numerous pits; rays homogeneous; parenchyma with chambered crystalliferous cells; tracheids rare, scattered ne ar the vessels. - Fig. 3-7. Lepidocordia punctata. - 3: Radial surface: vestured vessel-ray pits, SEM, x 1640. - 4: Tangential surface: ciosely spaced, vestured vessel wall pits, SEM, x 1560. - 5: Cross section: vessels in radially oriented clusters or chains; at the growth boundary with a slight tangential tendency; parenchyma apotracheally diffuse or in uniseriate aggregates, x 30. - 6: Cross section: fibres with a wall: lumen: wall ratio of about 1 : 2: I, x 110. - 7: Tangential section: rays storied, homogeneous and up to triseriate. Parenchyma with chambered crystalliferous cells, x 110. - Fig. 8-10. Pteleocarpa lamponga. - 8: Cross section: vessels solitary and evenly dis tributed; parenchyma in short, uniseriate bands, mostly unilateral, x 30. - 9: Ibid., vessels round or slightly angular; fibre-tracheids thick-walled, x 110. - 10: Tangential section: rays slightly heterogeneous; fibre-tracheids with pits in up to three series, x 110.

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Table I. Diagnostic features of Antrophora, as the uniIaterally banded parenchyma, hetero Lepidocordia and Pteleocarpa. geneous rays and the weIl developed fibre-tra cheids. This combination is unique within the

~ ~ '/> '/> Boraginaceae and thus somewhat corroborates Q) Q) the uncertain position assigned to the genus ~ P. P. '/> Q) S S Pteleocarpa by botanists. The anatomy of the P. '/> '/> secondary xylem is, notwithstanding the simple '" "0'" <::! ·SI "8 <::! vessel perforations and smaIl intervessel pits, to ... ~'/> "l:lo g 0"<:: ~~ be considered little derived in phylogenetic ~u Ci ~ <::! ' ~.:: g S terms, in comparison to Antrophora and Lepi "o SQ) o...... '" ~2 docordia...... n ~'/> 0;" .....'/> S::0l "0l Desch (1957) and Metcalfe andChalk (1950) ..... "" ~~ ~"" gave Iimited information on the wood of P ma Vessels laccensis Oliver, now considered a synonym of solitary + P lamponga (Sleumer, personal communica in radial groups + + tion). Their data agree with the present descrip diameter (J.Lm) 50 55-65 100-110 tion. perforations simple + + + pit diameter (J.Lm) 2.5 2.5 -3 4 Discussion pits vestured + + + The only characters shared by the secondary xylem of the three genera investigated are Rays the diffuse-in-aggregate to narrowly banded pa heterogeneous + renchyma and the minute vestured intervascu storied + lar pits. The latter feature increases the number width (in cells) 1-2 2-3 2-3 of boraginaceous genera known to possess ves tured pits (MiIler, 1977) from three to five of Parenchyma mainly thirteen genera studied. The two monotypic apo tracheal + + + genera from South America, Antrophora and crystals + + Lepidocordia, show a higher degree of struc tural conformity between them than to any Fibre-tracheids with other genus within Boraginaceae due the simi numerous distinct- larity in vessel distribution and the type of pa Iy bordered pits renchyma. This apparent affinity corresponds common + to Johnston's (1950) appraisal who states that "Antrophora has its dosest relative in Lepido cordia." Another striking parallel between Microscopic features (Figs.8-10): flower morphological and wood anatomical Vessels solitary, round to oval in cross sec considerations is that Lepidocordia is unique in tion, in part with a slightly angular outline; dia both respects: it has flowers without a stylus meter 100-110 J.Lm, walls about 2 J.Lm thick; and the wood shows storied rays. Both features perforations simple and weakly oblique (45°); are otherwise unknown in the family of Bora pits round and vestured, diameter 4 J.Lm, widely ginaceae. (Metcalfe and Chalk (1950) reported spaced (max. 4 per 500 J.Lm 2). Rays heteroge storied rays in Tourne[ortia, but in a study of neous with I to 3 rows of square or upright more than 30 sampies I could not find any cells, bi- or triseriate, 18-20 cells high (= 350- trace of them.) The attribution of both genera 380 J.Lm); partly with brownish, gummy depos to the subfamily of Ehretioideae opted for by its; pits to vessels not numerous, mostly in Johnston is in good agreement with anatomical short uni- or biseriate lines, similar to vessel considerations; any relationship construed on fibre pits. Parenchyma abundant, mostly in structural grounds indicates a certain proximity unilateral uniseriate bands; strandsof 5-8 cells; only to the genus Ehretia. In this context, how ceillength c. 100 J.Lm; cell diameter 20-30 J.Lm; ever, it is necessary to mention that Ehretioi walls about 2 J.Lm thick, partly with light brown deae shows a much greater wood anatomical ish gum-like deposits. Fibre-tracheids with dis range than the other boraginaceous subfamilies. tinctly bordered pits constituting ground tissue, The tropical Asiatic genus Pteleocarpus re polygonal, diameter 25-30 J.Lm, walls 6-9 J.Lm veals an entirely different structural pattern. thick, length 400-1350-2200 J.Lm; pits vestur Within Boraginaceae it shows a Iimited resem ed, uni- to triseriate, diameter 4-5 J.Lill. blance only to Bourreria. When foIlowing the The most characteristic features of Pteleo criteria established above, wood anatomical carpa lamponga are the soIitary vessels as weil evidence sould only warrant its placement in

Downloaded from Brill.com09/28/2021 03:56:52AM via free access IAWA Bulletin n.s., Vo!. 3 (3-4),1982 165 the structurally heterogeneous subfarnily Ehre References tioideae. Moreover, the rather primitive wood Aristeguieta, L. 1973. Familias y generos de los structure would allow its placement solely at arboles de Venezuela. Inst. Bot. Univ. the very base of the family's evolutionary de Centr. Ven., Caracas. velopment, a contention supported by Sleumer Bailey, LW. & R.A. Howard. 1941. The compa (1942) on morphological (flower and fruit) rative morphology of the Icacinaceae. L grounds. Even the possibility of placing Pteleo J. Am. Arbor. 22: 125-136. carpa outside the Boraginaceae in other fami Carlquist, S. 1970. Wood anatomy of Echium lies cannot be excluded when considering wood (Boraginaceae). Aliso 7: 183-199. structure. In fact, generic history shows ample Desch, H.E. 1957. Manual ofMalayan timbers. evidence of the indecision accompanying the L Govt. Malaya, Kuala Lumpur. attempts of properly c1assifying this genus. Ducke, A. 1925. Lepidocordia punctata. Arch. Among the families to which Pteleocarpa was Jard. Bot. Rio Janeiro 4: 170-172. attributed originally, Sapindaceae (Miquel, Endert, F. H. 1925. Boschbouwkundige Aan 1860) must be considered incompatible because teekeningen. Tectona 18: 71-78. of consistent structural differences of the sec Heyne, K. 1927. Nuttige planten van Neder ondary xylem. The placement in Olacineae landsch Indie. II. Ed. 2. Dept. Landbouw (now Olacaceae and Icacinaceae) proposed la Nijverheid en Handel, Ned. Indie. ter by Oliver (in Ridley, 1923) also raises con Johnston, LA. 1935. Studies in Boraginaceae. siderable doubts although these families show X. J. Am. Arbor. 16: 1-64. at least some agreement with Pteleocarpa in -- 1950. Studies in the Boraginaceae. XIX. terms of structural principles involved. Incor J. Am. Arbor. 31: 172-187. poration in Icacinaceae was already seriously King, G. 1895. Materials for a Flora of the Ma questioned by Bailey and Howard (1941), and layan Peninsula. J. Asiat. Soc. Bengal 64: would not be acceptable on anatomical grounds. 130-132. The comparison with Cardiopterygaceae, an Metcalfe, C. R. & Chalk, L. 1950. Anatomy of association for Pteleocarpa proposed by King the dicotyledons. Ir. Clarendon Press, Ox (1895) and rejected by Sleumer (1942), is not ford. possible because the corresponding genus Peri Miller, R. B. 1977. Vestured pits in Boragina pterygium (Cardiopteris) is herbaceous. ceae. IAWA BuH. 1977/3: 43-48. Obviously those families indicated by taxon Miquel, F.A.W. 1860. Prodromus Florae Suma omists as possible relatives for Pteleocarpa show tranae. FI. Ind. Bat. Supp!. I: 511. little or no resemblance with regard to the sec Pearson, R.S. & H.P. Brown. 1932. Commercial ondary xylem. Moreover, an equal or even bet timbers of India. II. Govt. India, Calcutta. ter match for Pteleocarpa can be observed in a Record, S.J. & W. Hess. 1941. American woods number of different other families, as for in of the family Boraginaceae. Trop. Woods stance in genera of Apocynaceae and Rubia 67: 19-33. ceae, but also of Humiriaceae and Linaceae. Ridley, H.N. 1923. The Flora of the Malay Accordingly, from a wood anatomical point Peninsula. II. Reeve, London. of view the genera Antrophora, Lepidocordia Sleumer, H. 1942. Peripterygiaceae. In: A. Eng and Pteleocarpa can be accepted as Boragina ler & K. Prantl, Die natürlichen Pflanzen ceae only because this family already incorpo familien 20b: 397-400. rates subunits of fundamentally different struc Stern, W. L. 1978. Index Xylariorum. Institu tural features ofthe secondary xylem. However, tional wood collections of the world. 2. a marginal position of Antrophora and Lepido Taxon 27: 233-269. cordia within the Boraginaceae, and treatment of Pteleocarpa outside the family would do better justice to the wood anatomical evidence.

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