Wood and Bark Anatomy of Myricaceae: Relationships, Generic Definitions, and Ecological Interpretations

Home , Canacomyrica, Comptonia (plant), Comptonia peregrina, Myricaceae, Myrica gale, Myrica hartwegii

WOOD AND BARK ANATOMY OF MYRICACEAE: RELATIONSHIPS, GENERIC DEFINITIONS, AND ECOLOGICAL INTERPRETATIONS

SHERwIN CARLQuIsT Santa Barbara Botanic Garden 1212 Mission Canyon Road Santa Barbara, Caltf 93105

ABSTRACT

Wood anatomy of the single species of Canacomyrica (hitherto not studied) shows that it belongs in Myricaceae, although it differs from other genera in several respects (axial parenchyma grouped in bands or columns as well as diffuse: Heterogeneous Type I rays: more numerous bars per perforation plate). The latter two features are primitive for the family. The four genera (Canacornyrica, Compronia, Morella, and Myrica s.s.) differ from each other not only by qualitative features but by quantitative features (feature means in genera mostly non-overlapping). Wood of Comptonia and Myrica s.s. lacks chambered crystals in axial parenchyma and ray crystals. Wood of Myrica s.s. has tracheids in latewood but fiber-tracheids in earlywood. Diagnostic generic summaries are presented. Features of Myr icaceae such as scalariform perforation plates, presence of (true) tracheids, ray types, chambered encapsulated crystals in axial parenchyma, and bark anatomy correspond with character States and expressions in Betulaceae, Casuarinaceae, Corylaceae, Juglandaceae (including Rhoipteleaceae), Ti codendraceae and, to a lesser extent, Fagaceae and Nothofagaceae. This grouping of families can be found as Fagales in recent DNA trees. The predominance of tracheids in basal Fagales such as Myr icaceae and Ticodendraceae suggests that origin of vasicentric tracheids which occur in combination with libriform fibers in Fagaceae is the product of tracheid dimorphism. Low imperforate tracheid length to vessel element length ratios (F/V ratios) in Myricaceae are a probable indication of wood primitiveness. Quantitative vessel features of Myricaceae, as combined in Mesomorphy Ratio values, characterize wood of Myricaceae as a whole, but at the species level such values correspond to respective habitats; notably high vessel density in Comptonia may represent greater conductive safety appropriate to relatively dry habitats. Key words: Canacomyrica, ecological wood anatomy, eurosids, Fagales. Morelia, systematic wood anatomy, tracheids, vasicentric tracheids, vessel grouping.

INTRODUCTION Chev. but more commonly under Myrica as a genus separate from the remainder of the family. The correct No monographic study of wood anatomy of Myri name for this small genus is not Gale, as assumed by caceae exists, although details of wood of a scattering Hylander (1945), who mistakenly thought that Myrica of species of Myricaceae can be found in a number of cerfera L. is the type species of Myrica (see Elias, publications (see Gregory 1994). A condensed sum 1971, 309), but Myrica, because the type of the mary based on a small number of species can be found p. genus is actually Myrica gale L. Elias (1971) recog in Metcalfe and Chalk (1950). The present study is nizes sections Gale and Morella as sections of Myrica, based on specimens of all species available in leading but more recent workers have xylaria, plus collections by the writer. This monograph raised these sections to genera. Morella is intended to address particular questions about the is being recognized by taxonomic systematics of Myricaceae and Fagales, but also to an workers (Knapp 2002), and in fioristic treatments such alyze the data in terms of ecology, habit, and particular as Kiflick et al. (1998) and Goldblatt and Manning anatomical modes of structure. (2000). Although in many families, wood features may Definitions of genera in Myricaceae have varied follow ecological adaptations primarily, and relatively considerably. The inclusion of Canacomyrica has been few criteria are present in wood features for generic questioned (Thorne 1968, 1976), although no alterna distinctions, that proves not to be true in Myricaceae. tive placement has been proposed (Cronquist 1981; The present study thus becomes an excellent example Thorne 2001). Wood anatomy of Canacomyrica has of systematic wood anatomy, in which all of the gen not been described hitherto. Comptonia seems univer era are amply distinguishable in terms of wood fea sally recognized as a monotypic genus (Elias 1971; tures. Unfortunately, all of the recognized genera have Cronquist 1981; Thorne 2001). Likewise, a number of not been sampled for the purpose of constructing workers have treated the species sometimes formerly DNA-based phylogenetic trees, and such data is much known as Gale hartwegii A. Chev. and G. palustris A. needed. DNA data is available for only a tiny fraction 8 Carlquist ALISO of the estimated 45 valid species of Myricaceae priate. The submersion of Rhoipteleaceae into Juglan (Thorne 2001). daceae (e.g., Thorne 2001) suggests that Rhoiptelea Myricaceae have been generally placed in Fagales must be included in comparisons also. Because the fa or Juglandales, if recognized separately from Fagales galean dade is a segment of the larger group now (summary of treatment of 12 phylogeneticists in Gold generally termed eurosids I (e.g., Soltis et al. 2000), berg 1986). Molecular data have confirmed this place Rosaceae might be expected to share some features ment. Analyses offer trees that place Myricaceae in the with Fagales as a whole and Myricaceae in particular. rosid line in a dade that corresponds to Fagales; close The controversial matter of aggregate rays and com ness to Juglandaceae is indicated (e.g., Soltis et al. pound rays, which are common in some Fagales (Met 2000), but some degree of proximity to Betulaceae and calfe and Chalk 1983) must inevitably be considered Casuarinaceae is also possible (Manos and Steele in terms of whether Myricaceae offer any equivalents 1997). If floral morphology is a reliable indicator of to such rays. Likewise, the relationship between tra relationships, female flowers of Juglandaceae are wor cheids in Myricaceae and vasicentric tracheids in Fa thy of consideration. Just as the female flowers of Jug gaceae needs examination. landaceae have inferior ovaries (Cronquist 1981), Myricaceae occupy a range of habitats, apparently those of Myricaceae also appear to be epigynous mostly mesic. Youngken (1919) claims swampy hab (MacDonald 1989). In Canacotnyrica (Fig. 1), this itats br all eastern U.S. species except for Comptonia, seems to be true, because a crown of five teeth, pre which “thrives in dry sterile soil.” Morella calfornica sumably calyx teeth, crown the fruit. Alternatively, occurs in canyons and moist slopes, whereas Myrica these have been interpreted as a late-developing disc hartwegii is found on montane stream banks (Munz that envelops the ovary (Cronquist 1981). Three 1959). The South African species (Morella) occur on branched stigmas (dark in Fig. 1) tip the fruit of Can sandstone or on sandy or limestone slopes (Goldblatt acomyrica. Between the calyx teeth and the stigmas and Manning 2000), but those authors do not describe are stamens, rendered visible in Fig. 1 by their cov water availability in these localities. Canacomyrica ering of pale golden glandular trichomes (some of grows in moist forest near the summit of the Montagne these trichomes are also seen on the bract below the des Sources, New Caledonia (original observation). ovary). MacDonald (1989) figures apparent apical The range in quantitative vessel data within the family bracts, like the putative calyx teeth of Canacomyrica, is considerable, indicating that adaptation to a range for Myrica gale. The apical androecium of Canaco of habitats has occurred, so analyses like those of myrica has a counterpart in the apical androecium fig Cariquist and Hoekmart (1985) are undertaken. ured for Morella californica (MacDonald 1989). The female flowers of Canacomyrica show at least super MATERIALS AND METHODS ficial similarity to flowers of pomoid Rosaceae, if the above intepretation is correct. MacDonald (1989) in Specimens documenting collections studied are as terprets Comptonia as unique among Myricaceae in follows (xylaria abbreviated according to Stern 1988): having a superior ovary. Developmental studies of Canacomyrica monticola Guillaumin, tree to 7 m, up myricaceous flowers are very much needed. to 12 cm in diameter at base, in Araucaria humbold The notion that Canacotnyrica does not have or tensis woodland, with Balanops, Dacrvdium, and thotropous ovules was corrected by Leroy (1949, Strasburgeria, ridge near summit of Montagne des 1957), who also demonstrated that what Guillaumin, Sources, New Caledonia. Carlquist 15290 (RSA); in describing the genus, thought was an elongate fu Comptonia peregrina (L.) J. M. Coulter, barren flats niculus is actually a prolonged integument (see Cron adjacent to Logan Airport, Boston, Massachusetts, quist 1981, for a full account). Sundberg (1985) has U.S.A., Cariquist 634 (RSA); Morella californica concluded that pollen of Canacomyrica is compatible (Cham. & SchIdi.) R. L. Wilbur, cultivated at Rancho with that of other Myricaceae, although generically Santa Ana Botanic Garden, Claremont, California, distinct. U.S.A.; M. cerfera Small, Yale-49459, Florida Keys, Thus, comparisons of wood of Myricaceae with that Florida, U.S.A., W. L. Stern 1955; M. domingana (C. of other Fagales, especially Juglandaceae, are appro DC.) Cariquist, comb. nov. [Myrica domingana C.

-4

Fig. 1—5. Canacomyrica monticola.—1. Fruit on inflorescence axis, bracteole at base and anthers at apex are distinguished by their coverings of pale glandular trichomes; stigmas (dark gray) at summit of fruit; note pointed structures, which may be calyx teeth, below anthers.—2—3. Radial sections of wood.—2. Strands of axial parenchyma bearing rhomboidal crystals (above) and upright cells of uniseriate ray (below).—3. Radial files of crystal-bearing cells in multiseriate ray (arrows), separated from each other by cells that lack crystals.—4. Transection of wood, narrower latewood vessels near bottom—S. Tangential section of wood; uniseriate rays have upright cells, multiseriate rays are composed of procumbent cells with some upright sheathing cells. Fig. 1, scale bar = 1 mm; Fig. 2, scale bar at top, divisions 10 im; Fig. 3—5, scale bar at top of Fig. 3, divisions = 10 i.m. VOLUME 21, NUMBER Myricaceae: Wood and Bark Anatomy 9 IIIIIIIIIiIIIIIIJJI[[[IIiIIjIIjJ l0 Cariquist ALISO

DC.j, Dominican Republic, USw-1929, in RSAw; M. term vasicentric tracheid is used in accordance with faya (Ait.) R. L. Wilbur, adventive in forests of Kokee, Carlquist (2001), a usage that follows closely the usage Kauai, Hawaii, U.S.A., Cariquist 523 (RSA); M. mo of Metcalfe and Chalk (1950), and the term “apotra dora (W. Bartram) Small, SE U.S.A., Stearns 21, cheal columns” is proposed for a grouping of axial USw-160135; M. javanica (Blume) I. M. Turner, Java, parenchyma cells found in Canacomyrica. The ar SJRw-3 1834; M. kraussiana (Buchinger ex Meisn.) D. rangement of photographs (Fig. 1—45) is alphabetical J. B. Killick, S. Carlquist 8067 (RSA), cult. Kirsten by genus. bosch Botanic Garden, South Africa; M. microcarpa Benth., Jamaica, USw-6105; Morella nagi (Thunb.) RESULTS: WOOD ANATOMY Carlquist comb. nov. [Myrica nagi Thunb., Nova Acta Soc. Sci. Upsal. 4:37. 17831, cult. Bot. Gard. Univ. Growth Rings Tokyo, S. Carlquist 7880 (RSA); Morella pubescens Most Myricaceae show growth rings, ranging from (Hunt. & Bonpi. ex Willd.) R. L. Wilbur, Peru, coil. almost imperceptible, as in Canaconzyrica (Fig. 4, late- Wurdack (US), USw-32525; M. quercifolia (L.) J. B. wood at bottom) to more pronounced, as in Comptonia Killick, cult. Kirstenbosch Botanic Gardens, South Af (Fig. 8), Morella caitfornica (Fig. 10), M. inodora rica, Carlquist 8062 (RSA); M. rubra Lour., cloud for (Fig. 14), M. nagi (Fig. 16), M. rubra (Fig. 38, 40), est surrounding Panar Laban Cabin, Mt. Kinabalu, M. quercifolia, Myrica gale (Fig. 42), and M. hartwe 3800 m, Sabah, Malaysia, S. Carlquist 15495 (RSA); gii (Fig. 44). No appreciable growth ring formation M. salicifolia (A. Rich.) B. Verdcourt & R. M. Poihill, was observed in M. javanica (Fig. 26), M. kraussiana Uganda, PRFw-26591; Myrica gale L., NE U.S.A., (Fig. 30), or M. pubescens (Fig. 32). Growth rings, Pease 325 (RSA); M. hartwegii S. Watson, cult. Ran where minimal, feature a small change in vessel di cho Botanic Santa Ana Garden, Claremont, California, ameters between earlywood and latewood (Fig. 4, 12). U.S.A. The genus Myrica as recognized here (M. gale In species of Morella with more pronounced growth and M. hartwegii, also the genus Gale of some au rings, the latewood is brief, i.e., most of the growth thors) is termed Myrica s.s. (sensu stricto) here so as ring contains vessels of moderate diameter and nar to distinguish it from the more inclusive Myrica of rower vessels are formed only a short distance prior many earlier authors. to the ends of the growth rings. In species with more The wood and bark samples were all available in pronounced growth rings, the latewood tracheids tend dried form. Samples were boiled and stored in 50% to be thicker walled and radially narrower than those aqueous ethanol. Woods of Myricaceae are not excep in earlywood (Fig. 14, 16, 40). tionally hard or soft, so they can be sectioned on a Myrica s.s. is distinctive in having numerous vessels sliding microtome without pretreatment to mitigate in the earlywood (Fig. 42, 44). These vessels are hardness. adhered Bark to some wood sections and densely placed in earlywood, and therefore, the num provided usable data on bark anatomy. Sections for ber of vessels per group is higher in Myrica s.s. than permanent slides were stained with safranin and coun in other Myricaceae (Table 1, column 1). However; in terstained with fast green. Some sections were left un the latewood, vessels are sparse (Fig. 44, center) or stained, dried between clean glass slides, mounted on absent (Fig. 42, center). Thus, Myrica s.s. represents aluminum stubs, sputter-coated, and examined with a growth ring Type 5A or SB (Carlquist 2001), whereas Hitachi 2600N scanning electron microscope (SEM). the remaining Myricaceae fall into Type 1D (vessels Macerations were prepared with Jeffrey’s Fluid and wider in earlywood, tracheids wider in earlywood) or stained with safranin. Type 1C (vessels wider in earlywood, but tracheids Mean number of vessels per group is based on an about the same throughout the ring). average of counts in which a solitary vessel = 1, a pair of vessels in contact = 2, etc. (this can also be Quantitative Vessel Features defined as number of vessels divided by number of vessel groups, solitary vessels in that case counting as Vessel grouping (Table 1, column 1) is minimal in a group). Because vessel tips overlap considerably, a Myricaceae. One must view reports of vessel grouping transection of the overlapping region can appear as a in dicotyledons with tracheids as the imperforate tra pair of vessels, and care was taken to distinguish these cheary element type with care, because mistaking a instances from genuine pairs of vessels in contact. Ves transection of overlapping vessel ends as a pair of ves sel lumen diameter is measured rather than outside sels is easy to do. Vessel grouping is as low as one vessel diameter because the lumen diameter is signif finds in any family of vessel-bearing dicotyledons if icant hydrologically. Terms used are in accordance one deducts the two species of Myrica s.s. with the IAWA Committee on Nomenclature (1964), If one measures mean diameter of vessels as seen which distinguishes among tracheids, fiber-tracheids, in transection (Table I. column 2), narrower vessels and libriform fibers in dicotyledonous woods, but the characterize Comptonia peregrina, Myrica gale, and VOLUME 21, NUMBER I Myricaceae: Wood and Bark Anatomy 11

Fig. 6—9. Wood sections of Myricaceae.—6—7. Canacomyrica monticola.—6. Transection, vessel at bottom, axial parenchyma in bottom third of photo, and, in tracheids above, dark deposits outline the bordered pits.—7. Group of axial parenchyma strands (columnar apotracheal parenchyma) containing encapsulated rhomboidal crystals, from radial section.—8—9. Comptonia peregrina.—8. Transection of outer stem, bark at top (sclereid nests gray, parenchyma dark); secondary xylem below shows large vessels at the beginning of a growth ring.—9.

Tangential section; rays are mostly uniseriate, and are distinguishable by their dark contents. Fig. 6, 7. scale above Fig. 6 (divisions = 10 i.m); Fig. 8, 9, scale above Fig. 3. 12 Cariquist ALISO If k1IflHtP ;1r

1’ ITi- !jJ

I 4 t1Th1Ith’k 11

rcr i . -‘ ‘i

Fig. 10—13. Wood sections of Morella.—l0—l1. M. californica.—10. Transection: several growth rings evident, vessels relatively narrow—Il. Tangential section; dark-colored deposits essentially absent in rays.—12—13. M. faya.—12. Transection, no growth ring apparent.—13. Tangential section; multiseriate and uniseriate rays about equally frequent, some ray cells filled with dark-colored deposits. Fig. 10—13, scale above Fig. 3. VOLUME 21, NUMBER I Myricaceae: Wood and Bark Anatomy

Fig. 14—17. Wood sections of Morella.—14—15. M. inodora.—14. Growth ring below middle, evident by band of tracheids; no marked change in vessel diameter evident.—15. Multiseriate rays abundant, relatively short, composed of cells mostly filled with dark-staining compounds.—16—17. M. nagi.—16. Transection. growth ring near top distinguished by tracheid band; vessels relatively large in diameter.— I?. Tangential section; uniseriate rays abundant at lower left: dark-staining deposits common in almost all ray cells. Fig. 14—17, scale above Fig. 3. 14 Cariquist ALISO

,5.l*:\

1j-:

- •4••

Fig. 18—21. Wood details of Morella, shown by SEM (Fig. 18, 20, 21) and light microscopy (Fig. 19).—18---20. M. inodora.—18. Portion of perforation plate from radial section, with porose pit membrane transitional to lateral wall pitting above.—19. Ray cells as seen in radial section; dark-colored deposits outline lumina and pit cavities of ray cells, showing many of the pits to be bordered.—20. Droplets of dark-staining compounds in ray cells from radial section.—2 I. M. kraussiana; strand of encapsulated crystals of axial parenchyma strand from radial section; top two crystals intact, bottom crystal sheared off by sectioning; tracheids to left and right of axial parenchyma strand.—Fig. 18, 20, 21, scales = 2 im; Fig. 19, scale above Fig. 6. VOLUME 21, NUMBER 1 Myricaceae: Wood and Bark Anatomy 15

.. _; I

• f4 j; I.’ b i11

IHE

— ..

. — ‘r’1 Ii

- 14 - -ø __i 24 Fig. 22—25. SEM photographs of radial wood sections of Morella.—22. M. kraussiana. Perforation plate, with relatively narrow, numerous bars.—23--25. M. nagi.—23. Perforation plate with bars of typical thickness; bordered pits of tracheids are conspicuous to left and right of the vessel.—24. Perforation plate with relatively few, wide bars; prominent bordered pits of tracheids to the right of the vessel.—25. Portions of two tracheids, to show characteristic border diameters and pit aperture shapes. Fig. 22—24, scales = 10 p.m; Fig. 25, scale = 2 p.m. Cariquist ALISO i.I Ih11WI I1. .1 . I1L’i; > . . 4 .j . . 1. ,. : ( i ‘r•4- ‘I’ ; %_

-• )tI “

28 r

Fig. 26—29. Wood sections of Morella.—26—28. M. javanica.—26. Transection; growth rings absent, vessels notably wide.—27. Tangential section; wide as well as narrow multiseriate rays are present; both multiseriate and uniseriate rays contain dark-staining deposits.—.28. Tran section. showing thick-walled tracheids in which deposits of dark-staining material outline the bordered nature of the pits; a pair of rhomboid crystals, Just above center, and, to right and left of the crystal-bearing cell, axial parenchyma cells.—29. M. salicifolia; transection; axial parenchyma is diffuse and, a little below center, a band of diffuse-in-aggregates axial parenchyma is present; dark deposits in rays and in a few of the axial parenchyma cells. Fig. 26, 27, scale above Fig. 3; Fig. 28, scale above Fig. 6; Fig. 29, scale above Fig. 2. VOLUME 21, NUMBER I Myricaceae: Wood and Bark Anatomy 17

Fig. 30—33. Wood sections of Morella.—30—3 1. M. kraussiana.—30. Transection; relatively narrow vessels characteristic of a temperate species.—3l. Tangential section; multiseriate rays are narrow; dark-staining deposits are sparse.—32—33. M. pubescens.—32. Transection; relatively wide vessels characteristic of a tropical species.—33. Tangential section with narrow multiseriate rays, but with dark deposits in many cells of both uniseriate and multiseriate rays. Fig. 30—33, scale above Fig. 3. ______

18 Cariquist ALISO

‘ - 1.t- JFF I ‘. j

I. I

r ; !:‘4 ‘44

5: ., I, 4 — 4% I

I i

I -36 Fig. 34—37. SEM photographs of radial Sections of wood of Morella pubescens.—34. Perforation plate with numerous bordered bars and, to right, three tracheids showing bordered pitting.—35. Perforation plate with an intermediate number of rather slender bars and, on the lateral wall, alternate pitting on a vessel face that probably was in contact with tracheids.—36. Perforation plate with few, narrow, minimally bordered bars; pitting sparse on lateral wall of vessel.—37. Pit apertures of three pits facing a tracheid lumen, to show narrowly elliptical pit aperture shapes. Fig. 34—36, scale = 10 p.m; Fig. 37, scale = 2 p.m.

M. hartwegii. Narrow vessels were also observed in Mean vessel density (Table 1, column 3) shows an Morella quercifolia, although the small diameter (6 amazing range from 11 per mm2 (Morella javanica, cm) of that wood sample and the fact that this species Fig. 26) to 260 per mm2 (Comptonia peregrina, Fig. is shrubby rather than arboreal may account for this. 8). This range is greater than one might expect from The widest vessels observed in the study were those the span of vessel lumen diameters in the family. This of M. javanica (Fig. 26). The transections of wood circumstance will be examined below in terms of pos presented at the same scale (Fig. 5, 8, 10, 12, 14, 16, sible physiological significance. 26, 30, 32, 38, 42, and 44) show that there is an ap Vessel element length (Table 1, column 4) ranges preciable range in vessel diameters within the family, from relatively short in the shrubs Comptonia pere and these photographs accurately reflect the mean lu grina (477 m) and Morella quercifolia (462 jim) to men diameters recorded in Table 1, column 2. long in trees such as M. javanica (800 jim), M. dom VOLUME 21, NUMBER I Myricaceae: Wood and Bark Anatomy

—— —

Fig. 38—41. Wood sections of Morella rubra (Fig. 38—40) and M. quercfo1ia (Fig. 41).—38. Transection; clearly demarcated growth ring present.—39. Tangential section; cells of rays are relatively large; many contain dark-staining deposits.—40. Transection; growth ring ends with narrow vessels, thick-walled tracheids.—41. Tangential section; rhomboidal crystals (arrows) occur in multiseriate rays. Fig. 38, 39, 41, scale above Fig. 3; Fig. 40, scale above Fig. 2.

Fig. 3. above scale 42—45, Fig. present. rays are multiseriate

few plus

rays

uniseriate

numerous

section; Tangential of earlywood.—45. at beginning crowded in latewood, sparse are vessels top; at

with bark

Transection hartwegii.—44.

M. rays abundant.—44—45. uniseriate are rays narrow, multiseriate section; Tangential rings.—43.

growth of two the

latewood in are

absent above; vessels bark Transection, gale.—42. M. Myrica.—42—43. of sections Wood 42—45. Fig.

t. 45

1fr” ti)Ii

J.,

‘1

Ij.ui

Ti 1

‘Ii

‘. I

‘cj

I !

, t

rhi 1 !

IJ(

.‘ 43

i•

1!i

I” i1

I:•iti

I I I

I— I

!iiilI L’

.1 ‘‘I ‘‘ 1 1 t

II’’

‘llJ’Ii

In,’ 1

ALISO Cariquist 20 C

Table 1. Wood characteristics of Myricaceae.

I 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Species VG VD VM VL VW TL TW AP MU MW MH UH FV ME

Canaconrvrica monticola 1.10 56 39 713 2.4 24.8 (17—32) 891 5.5 D, DA, AC, AB M = U 4.7 1598 510 1.25 1024 Camptonia peregrina 1.19 30 260 477 2.0 0.2 (0—3) 701 3.5 D, DA, VS MU 2.5 474 173 1.69 250 M. cerifera 1.10 42 151 647 2.9 7.9 (0—16) 914 4.7 D, DA, VS M>U 2.6 527 228 1.41 180 M. domingana 1.04 48 51 801 1.8 8.8 (6—12) 1264 7.0 D, DA M = U 2.3 316 156 1.58 754 -I C) M. faya 1.03 54 34 669 1.2 9.0 (5—12) 958 2.5 D, DA, VS M U 3.0 429 239 1.43 1063 a M. inodora 1.17 41 174 750 1.0 3.6 (0—12) 1028 3.5 D M = U 3.5 433 140 1.37 177 aCD CD M. javanica 1.03 133 11 800 4.0 6.6 (3—15) 1540 6.0 D, DA M = U 3.7 447 287 1.93 9693 M. kraussiana 1.03 48 77 541 1.5 10.3 (0—17) 1075 2.4 D, DA M = U 2.8 565 171 1.99 337 0 0 M. microcarpa 1.06 71 56 759 1.8 7.5 (3—15) 1323 5.2 D M>U 3.4 385 185 1.74 962 0. a M. nagi 1.08 60 56 560 1.1 6.6 (3—12) 825 5.4 D, DA M>U 3.8 789 249 1.47 600 0 C. M. pubescens 1.10 59 68 605 2.1 9.2 (5—14) 929 2.7 D, DA M = U 2.7 379 163 1.53 525 M. quercifolia 1.07 24 225 462 1.2 9.1 (0—15) 721 2.6 D, DA, VS M = U 2.3 475 162 1.56 49 a M. rubra 1.03 74 23 812 1.8 7.7 (6—10) 1243 5.0 D, DA, VS M>U 2.5 492 195 1.59 2613 M. salicifolia 1.09 24 0 84 710 1.7 7.9 (0—18) 1602 3.5 D, DA M>U 5.4 540 164 2.26 2485 a Mvrica gale 1.31 30 58 534 2.0 13.2 (5—17) 601 1.8 D, DA M

Legends: 1 (VG), mean number of vessel per group; 2 (VD). mean lumen diameter of vessels. rm; 3(VM), mean number of vessels per 2mm of transection; 4 (VL), mean vessel element length. jcm; 5 (VW), mean vessel wall thickness, p.m; 6 (BP), mean number of bars per perforation plate (followed in parentheses by range observed); 7 (TL), mean tracheid length, jsm; 8 (TW), mean tracheid wall thickness. cm; 9 (AP). types of axial parenchyma present (AB = apotracheal banded, AC = apotracheal columns, D = diffuse, DA = diffuse-in-aggregates, VS = vasicentric scanty); 10 (MU), relative abundance of multiseriate and uniseriate rays; 11 (MW), mean width of multiseriate rays at widest point, cells; 12 (MH) mean height of multiseriate rays, m; 13 (UH), mean height of uniseriate rays, sm; 14 (FV), mean F/V Ratio (vessel element length divided by tracheid length); 15 (ME), Mesomorphy Ratio (vessel diameter times vessel element length divided by mean number of vessels per 2).mm For additional comments and for collection data, see Materials and Methods. 22 Cariquist ALISO ingana (801 m) and M. rubra (812 pm). The mean there is only a slight tendency toward angular vessel for the family as a whole (641 urn) is remarkably close outline where vessels are crowded in earlywood (Fig. to the mean given by Metcalfe and Chalk (1950) for 42, 44). dicotyledons at large, 649 um. Pits on lateral walls of vessels are transitional, op Vessel wall thickness (Table 1, column 5) is much posite, or alternate on vessel to vessel interfaces, and less (family mean, 1.8 urn) than the thickness of tra types vary greatly within species. Vessel to vessel in cheid walls, and varies relatively little within the fam terfaces occur mostly in the overlap areas between ves ily. The thinness of vessel walls is perceptible in the sels, because degree of vessel grouping is so low. Ves higher-scale photographs (Fig. 6, 29). sel to ray pitting is scalariform (infrequently), transi Pits on lateral walls of vessels are oval to circular tional, opposite, or alternate, but rather frequently op and do not deviate much, throughout the family, from posite. On vessel surfaces in contact with tracheids, a diameter of 4 urn (pit cavity diameter measured par pits are opposite or alternate (Fig. 35). quite sparse in allel to long axis of vessel element), as seen in Fig. some areas (Fig. 36). Opposite or alternate pits have 22—24. Pits are slightly larger, averaging about 5 im pit cavities oval in face view, but the pit apertures in diameter, in Canacomyrica monticola (Fig. 6), Mo facing the vessel lumen are narrowly elliptical (Fig. rel/a californica, M. javanica (Fig. 28), M. pubescens 35). (Fig. 35), and M. salicifolia. Species with pits ap No helical thickenings or vesturing of any kind were proaching 3 urn in diameter include Morel/a cerifrra, observed in vessels of Myricaceae. M. faya, M. kraussiana, M. quercifolia, Myrica gale, Thin-walled tyloses, often containing resinlike de and M. hartwegii. posits, were observed in several Myricaceae; they were Perforation plates of Myricaceae are generally sca exceptionally common in material of Canacomyrica lariform, with a range of 1—32 bars (Table 1, column and Myrica hartwegii. 6). One genus, Comptonia, has simple perforation plates almost exclusively, with a very small proportion imperforate Tracheary Elements of the plates bearing one to three bars. At the opposite extreme is Canacomyrica, in which the material stud With the exception of the two species of Myrica, all ied averaged 24.8 bars per plate. Second to Canaco imperforate tracheary elements in Myricaceae are tra myrica is Myrica s.s., the two species of which to cheids. This designation is easy to make because the gether average 12.6 bars per plate. All of the species pit cavities are large (“fully bordered pits”) and the of Morella fall below Myrica in average bar number pits are densely placed (Fig. 23, 24, 34, and especially (Table 1, column 6; Fig. 22—24, 34—36). If one aver Fig. 25). Pit cavities filled with dark-colored com ages all species of Morella studied, one obtains the pounds show the bordered nature of the pits in tra figure of 8.0 bars per plate. Thus, the four genera have cheids (Fig. 6, 28). The apertures facing the lumina of notably different modes with respect to this feature. tracheids are slitlike (Fig. 37). Perforation plates with fewer bars per plate some In the two species of Myrica, a curious and subtle times have wider bars (Fig. 24) than those with more difference between earlywood and latewood occurs numerous bars (Fig. 22, 23), but exceptions are easy with respect to imperforate tracheary elements. In ad to find. Notably wide but relatively numerous bars dition to vessels, the earlywood contains fiber-tra (Fig. 34) and notably slender bars in plates with few cheids with sparsely distributed pits that have reduced bars (Fig. 35, 36) may readily be found. Where wider, pit borders (pit cavities ca. 1—2 jim in diameter). In the bars have easily seen borders (Fig. 18, 34), and latewood of both species, vessels are sparse or absent, probably no bars lack borders entirely, at least if one depending on the growth ring, and imperforate trache looks at the lateral ends of the perforations. ary elements are clearly tracheids. Fiber-tracheids in earlywood plus tracheids in latewood have also been Qualitative Vessel Features reported in Carpinus, Corylus, and Ostrya of the Cor ylaceae or Betulaceae (Metcalfe and Chalk 1950). The limits between perforation plates and lateral Note should be taken that the concept of vascular tra wall pitting are not as clear as one might think if one cheids, in which extremely narrow vessels grade into studies the transitional pits with SEM. Transitional pits tracheids (which are, in effect, vessels lacking perfo may bear porose pit membranes indicating only partial ration plates) in the last few layers of latewood, is lysis of the pit membrane (Fig. 18). Pit membranes of quite a different concept. pits on lateral walls of vessels do not bear these pores. Mean lengths of imperforate tracheary elements in Vessels are typically circular or oval in outline, the the family (Table 1, column 7) range from 493 jim to radial axis slightly longer than the tangential axis as 1602 urn, a considerable range. The species with the seen in transections (Fig. 4, 8, 10, 12, 14, 16, 26. 29, shortest mean imperforate tracheary element length are 30, 32, 38, 40). Even in the two species of Myrica, Myrica gale (601 urn) and M. hartwegii (493 jim). VOLUME 21, NUMBER 1 Myricaceae: Wood and Bark Anatomy 23

Mean wall thickness of imperforate tracheary ele such cells subdivided into cuboidal crystal-containing ments follows a pattern similar to the lengths. The cells (“chambered crystals”). No subdivision into means for Myrica gale and M. hartwegii are 1.8 im crystal-containing cells was observed in the two spe and 2.3 sm, respectively, whereas the range in species cies of Myrica s.s. or in Comptonia, and the lack of means for the three other genera is from 2.4 am to 5.5 such crystal strands is apparently a diagnostic feature im (Fig. 6, 29). In species with moderately to strongly of these two genera. Crystal-containing strands of cu demarcated growth rings, differences in wall thickness boidal cells were observed in Canacomyrica and in all between earlywood and latewood occur. For example, of the species of Morella, although these strands are in Comptonia (Fig. 8), earlywood tracheid wall thick scarce in some of the Morella species and abundant in ness is about 2.3 lam, whereas latewood wall thickness others. The nature of crystals in these strands is dis is about 4.7 m. The claim by Metcalfe and Chalk cussed further below under “Crystals.” (1950) that M. gale has imperforate tracheary element walls thicker than those of other Myricaceae is not Vascular Rays confirmed here; the reverse was observed. Mean pit cavity diameter of tracheids is essentially As shown in Table 1, column 10, multiseriate rays the same as the pit cavity diameter of lateral wall pits are more abundant than uniseriate rays, or approxi of vessels for any given species of Myricaceae (see mately equal in abundance in Canacomyrica (Fig. 5) data for vessel pits above). Contrary to what one sees and in Morella (Fig. 11, 13, 15, 17, 27, 31, 33, 39, in conifers and in many dicotyledon families, pitting and 41). Biseriate rays are considered multiseriate here is denser on tangential walls of tracheids in Myrica for purposes of comparisons. In contrast to those two ceae, sparser on radial walls. genera, uniseriate rays are more common than multis eriate rays in Comptonia (Fig. 9) and Myrica s.s. (Fig. Axial Parenchyma 43, 45). The two species of Myrica s.s. differ, however, in that multiseriate rays are scarce and narrow in M. Axial parenchyma in Myricaceae is basically dif gale (Fig. 43), in which the mean multiseriate ray fuse; diffuse parenchyma can be found in all species width (at the widest point) is 2.1 cells (Table 1, column (Table 1, column 9). In most species, diffuse-in-aggre 11). Multiseriate rays are more common in M. har gates (tangential aggregates of two to about five cells) twegii (Fig. 45), in which mean multiseriate ray width is commonly present in addition (Fig. 29). The type is 4.1 cells. However, this comparison may be mis “diffuse” implies random distribution of parenchyma leading because the specimen of M. gale was from a throughout the fascicular secondary xylem. Diffuse-in- narrower stem—the wood of a more juvenile character, aggregates is recognized because it is a departure from therefore—than that of M. harti’vegii. Rays tend to in randomness. In Comptonia peregrina, Morella ceri crease in width as woody stems increase in diameter fera, M. faya, M. quercifolia, and M. rubra, axial pa (Barghoorn 1940). The widest multiseriate rays in the renchyma cells adjacent to vessels seem a little more family were observed in Canacomyrica (Fig. 5) and numerous than randomness would dictate, so scanty Morella salicifolia (Table 1, column 11). In Morella, vasicentric parenchyma is said to be present in these greater width of multiseriate rays was observed in M. species. inodora (Fig. 15), M. javanica (Fig. 26) and M. nagi In addition, Canacomyrica possesses axial paren (Fig. 17), but narrower rays characterize M. californica chyma distributions not seen in the other Myricaceae: (Fig. 11), M. cerfera, M. domingana, M. faya (Fig. apotracheal bands and apotracheal groupings circular 13), M. kraussiana (Fig. 31), M. pubescens (Fig. 33), in transection. The latter type is infrequent enough in M. quercifolia (Fig. 41), and M. rubra (Fig. 39). Of dicotyledons so that it has not been recognized with a these, narrower rays might be related to small sample term, so “apotracheal columns” is proposed here for diameter in M. kraussiana and M. quercifolia, al groups composed of about five to ten cells as seen in though not in the other species. transection. Longisections of these types are seen in With respect to ray histology, the rays of most Myr Fig. 2 (upper left, crystal-containing cells) and Fig. 3 icaceae qualify as Heterogeneous Type hA, in which (upper left). Arrows indicate apotracheal strands in multiseriate ray tips are typically more than a single Fig. 4, and in Fig. 5, a strip of apotracheal parenchyma cell tall (Fig. 45; most rays of Fig. 13), or Heteroge runs down the center of the photograph (about ¼ the neous Type JIB, in which multiseriate ray tips are usu width of the photograph). ally a single cell tall (Kribs 1935; Carlquist 2001). Axial parenchyma strands, as seen in longisection, Rays of the latter type can be seen in all species of range from 3—8 cells. Varying numbers of these cells Morella, and are shown here in Fig. 27. Where mul may be subdivided into cuboidal crystal-containing tiseriate rays are very scarce (Fig. 43), one can say cells (Fig. 21). Thus, a strand might consist of three that the ray type is transitional between Heterogeneous or four undivided cells plus the equivalent of two more Type II and Heterogeneous Type III, and closer to the 24 Cariquist ALISO latter (in which all rays are uniseriate), These assign icaceae might be considered an example of disintegra ments for rays in Myricaceae agree with those of Met tion of multiseriate rays to form aggregate rays, but calfe and Chalk (1950). However, Metcalfe and Chalk the abruptness of the process in Myricaceae probably (1950) state that in Myricaceae, the multiseriate por disqualifies them from this designation. tions of multiseriate rays are “sometimes with sheath Uniseriate ray height is given in Table 1, column [= uprighti cells.” Such sheath cells are, in fact, very 13, As with multiseriate rays, relatively great mean scarce in most species, but are relatively common in uniseriate ray height was observed in the material of rays of Canaconzyrica (Fig. 5), which also has elon Canacomyrica, but uniseriate rays in Moreila, Mvrica gate uniseriate tips on multiseriate rays and therefore s.s., and especially Comptonia are shorter. is referable to Heterogeneous Type I of Kribs (1935). Ray cells have secondary walls in all Myricaceae. In Myricaceae as a whole, the multiseriate portions of Bordered pits are common in most species, especially multiseriate rays consist almost wholly of procumbent on tangential walls, but simple pits are more common cells (except in Canacomyrica) and the uniseriate tips in some species. Bordered pits are shown very clearly of multiseriate rays consist of upright cells. Uniseriate in sectional view in rays of Morella inodora (Fig. 19). rays consist of upright cells (Fig. 2, lower 2, of pho tograph). Occasional square cells may be observed in Crystals radial sections, but they are much less common than Rhomboidal crystals occur abundantly in cuboidal either upright or procumbent cells (Fig. 3). cells of the axial parenchyma strands of all types of Mean height of multiseriate rays in Myricaceae is axial parenchyma groupings of Canacomyrica (Fig. 2, relatively low and relatively uniform, 379 im to 784 7). These cuboidal crystal-containing cells (“cham m (Table 1, column 12) except in Canacomyrica bered crystals”) contain rhomboidal crystals covered (Fig. 5), which has a mean ray height of 1598 aim. with a layer of secondary wall material (“encapsulated The mean multiseriate ray height for the family as a crystals”). Similar strands of cuboidal crystal-contain whole is 539 jim, and this figure is reflected visually ing cells occur in some sheathing cells on multiseriate in the rays shown in Fig. 9, ii, 13, 15, 17, 31, 33, 39, portions of multiseriate rays of Canacomyrica. Crys 41, and 45. Metcalfe and Chalk (1950) report ray tals are also abundant in the central portions of mul height exceeding 1000 jim for M. nagi, but these rays tiseriate rays of Canacomyrica, in which they occur in must be infrequent and probably in wood from the radial series of procumbent cells (Fig. 3). Many such base of a relatively large tree. Metcalfe and Chalk crystals occur in vertically or horizontally subdivided (1950) did not study wood of Canacomyrica. procumbent ray cells. Crystals are so abundant in So-called aggregate rays (clustering of unisenate or wood of Canacomyrica that wood sectioning inevita biseriate rays into larger units: IAWA Committee on bly produces imperfect results. Nomenclature 1964) are reported most commonly in Outside of Canacomyrica, crystals in rays were ob Fagales, but occasionally in other families (Carlquist served only in Morella quercfolia (Fig. 41) and M. 2001). Aggregate rays have not been reported in Myr rubra. icaceae, apparently. A phenomenon that some might All species of Morella were observed to have cham refer to this phenomenon is visible in some Myrica bered crystals in axial parenchyma strands. Some of ceae. In transection, one can see multiseriate rays that these crystals are so heavily covered (encapsulated) abruptly break into uniseriate or biseriate rays; these with secondary wall material that virtually no lumen slender rays, in large stems, become wider toward the space remains in the cell. This covering can be seen outside of the stem, in agreement with the increase in on the lower two crystals in Fig. 21. The crystals in ray width with age noted by Barghoorn (1940). The Fig. 21 are more complicated in shape than simple association of uniseriate rays into groupings (perhaps rhomboids. Crystals in axial parenchyma can be seen represented in Fig. 17, lower left) decreases rapidly in transections (e.g., Fig. 28). Crystal strands are com with age, and certainly does not increase as the stems mon in some species of Morella, rare in others. How increase in diameter, as the term “aggregate,” indi ever, a careful search revealed at least a few cham cating a kind of “coming together,” suggests. The ter bered crystals in all species of Morella. Complete ab minology for the rapid breakup of wide primary rays sence of chambered crystals from the genus cannot be as secondary growth begins in Myricaceae is problem claimed in any species of Morella in the present study. atical, therefore. The idea that aggregate rays are large No crystals were observed in wood of Comptonia multiseriate rays in the process of disintegration is a or Myrica s.s. generalization offered by Bailey and Sinnott (1914) and Barghoorn (1941), but the reverse (progressive Starch and Resinlike Deposits clustering or union of uniseriate rays with age of stem) has been demonstrated repeatedly (see Carlquist 2001). Starch grains were observed in axial parenchyma of The existence of multiseriate rays near the pith of Myr Morella californica and M. nagi, and in the axial pa- VOLUME 21. NUMBER I Myricaceae: Wood and Bark Anatomy 25 renchyma and rays of M. salicfolia. Doubtless starch SYSTEMATIC AND PHYLOGENETIC CONCLUSIONS is more widely present in wood of the family, but was The four genera of Myricaceae not observed because some methods of preservation are so different on the basis of wood anatomy that diagnostic tend to promote loss of starch (e.g., bacterial action summaries, given below, can be developed. These summaries, during slow drying). Some objects I interpret as starch however, could eventually be expanded more precisely remnants were observed in several species of Myri in caceae. terms of quantitative features if wood samples of similar degrees of maturity were available. Dark-colored resinlike deposits are common in axial Some quantitative estimates are included in these summaries and ray parenchyma cells, and account for the darkness in the form of terms such as “short” and “interme of these tissues in Fig. 5, 9, 12, 13—33, 38—41, and 43. diate,” and these designations can be translated into These deposits may be in the form of droplets (Fig. more precise numerical terms by reference to Table 1. 19, left; Fig. 20), a thin layer lining cells (Fig. 6), or more massive accumulations filling all or part of a cell 1. Canacomvrica. Vessels scattered among tracheids. (Fig. 13, 19, 27, 31, 33, 39, 43). Although most com Vessel elements long. Mean number of bars high. mon in rays, dark-colored deposits occur also in axial Tracheid length long; tracheid walls thick. Paren parenchyma (Fig. 29), Deposits even spread into tra chyma diffuse, diffuse-in-aggregates, in apotracheal cheary elements (Fig. 6, 28). bands, and in apotracheal columns; strands com posed of 3—4 long cells plus long cells subdivided into cuboidal cells each containing an encapsulated RESULTS: BARK rhomboidal crystal (chambered crystal). Multiser In Comptonia bark, there is a band of sclereids sep iate rays about as abundant as uniseriate rays; crys tals comon procumbent arating outer from inner cortex (not shown in Fig. 8), in ray cells that are usually subdivided. Multiseriate Scattered druse-bearing parenchyma cells and strands rays tall, the multiseriate portion with sheathing of fibers occur in secondary phloem of Comptonia cells; ray type Heteroge (Fig. 8, top). neous Type 1. Crystals present in procumbent (and usually subdivided) ray cells In Myrica gale (Fig. 42), druses are present in the of multiseriate rays. 2. Comptonia. Vessels narrow, scattered outer cortex. A layer of sclereids is present in the inner among tra cheids. Vessel elements short. Perforation cortex. In M. hartwegii (Fig. 44), numerous druses oc plates mostly simple, mean number of bars very low. Tra cur in the outer cortex along with a few fibers, but no cheid length intermediate. Tracheid sclerenchyma layer was observed. wall thickness varies with position in growth rings. Apotracheal In Morella quercifolia, rhomboidal crystals occur in diffuse, diffuse-in-aggregates, occasionally scanty idioblasts in the outer cortex and a sclerenchyma layer vasicentric; strands composed of about four long encircles the stem in the central cortex. Fiber bands cells, none subdivided into cuboidal cells. Multis and rhomboidal crystal-containing idioblasts are pre eriate rays few, short, lacking sheath cells, Hetero sent in secondary phloem. geneous Type JIB. Uniseriate rays more common Where the band of sclereids (forming a cylinder in than multiseriate rays. Crystals absent. three dimensions) occurs in the cortex of Myricaceae, 3. Morelia. Vessels moderately wide, scattered among it is continuous around the stem regardless of the age tracheids. Vessel elements intermediate in length. of the sample (at least in the present study). Breaks Perforation plates with bars fewer than in Cana inevitably occur in the cylindrical band of sclereids as comyrica or Myrica (when given in terms of the xylem cylinder increases in diameter; but as in oth means). Simple perforation plates infrequent. Tra er dicotyledons with such a sclerenchyma cylinder in cheid length intermediate to long. Tracheid wall bark, parenchyma cells adjacent to sclerenchyma the thickness, intermediate, less than that of Canaco band doubtless divide, intrude into the break, and be myrica, more than that of Myrica s.s. Apotracheal come converted into sclereids. parenchyma diffuse or diffuse-in-aggregates, com In all species of Myricaceae for which bark was posed of strands of 2—6 long cells intercontinuous available, periderm is present outside of the cortex and with chains of cuboidal cells each containing one consists of cells much narrower radially than tangen crystal. Multiseriate rays more abundant than un tially. There is a tendency for phellem to exfoliate as iseriate rays. Sheathing cells lacking on multiseriate thin sheets. The stem specimens of species for which portions of multiseriate rays, rays Heterogeneous bark was available were relatively small in diameter, Type IJA or Heterogeneous Type JIB. Crystals pre so persistence of the cortex by means of tangential sent in rays of a few species. stretching and radial subdivision of cortical cells was 4. Myrica s.s. (Gale of some authors). Vessels narrow, observed. In bark of older stems, loss of cortex is to crowded in earlywood (number per group higher be expected. than in other genera), sparse or absent in latewood. 26 Cariquist ALISO

Perforation plates with bar number means inter tremely low mean number of bars per perforation mediate between that of Canacomyrica and those plate. Thus, the recognition of four genera is support of Morella. Imperforate tracheary elements shorter ed. Sampling of Morella here is insufficient to judge than in Canacomyrica or Morella; the elements are whether subgenera proposed within Morella (see Elias tracheids in latewood but fiber-tracheids in early- 1971) receive any support from wood anatomy, how wood; wall thickness of imperforate tracheary ele ever. ments is uniformly thin. Axial parenchyma diffuse Inclusion of Myricaceae in Fagales (near Juglanda or diffuse-in-aggregates. Axial parenchyma strands ceae, Casuarinaceae, and Betulaceae) is proposed by composed of 3—4 long cells, no chains of cham recent phyletic studies that utilize DNA analysis (Ma bered crystals present. Multiseriate rays fewer than nos and Steele 1997; Soltis et al. 2000). Fagaceae form uniseriate rays, sheath cells lacking, rays Type het a dade adjacent to the dade formed by the preceding erogeneous Type hA and JIB. Crystals absent in four families by Soltis et al. (2000); Corylaceae are rays. frequently included in Betulaceae and are close to Be tulaceae even if recognized at the familial level. The above comparisons support the classification of Rhoipteleaceae are now indicated as optionally includ Elias (1971) who, however, recognized Morella and ed in Juglandaceae (APGII 2003). Nothofagaceae and Myrica s.s. as subgenera rather than as genera; the di Ticodendraceae are clearly in Fagales (APGII 2003), agnostic features above support recognition of these as but were not included in the tree of Soltis et al. (2000). genera. The ray type Heterogeneous Type I and the Assuming that these families are the ones most rele relatively large number of bars per perforation plate vant for comparison to Myricaceae, distribution of fea found in Canacomyrica, a genus not considered by tures found also in Myricaceae can be listed as follows Elias, are features that are primitive within the family. (data from Moseley 1948; Metcalfe and Chalk 1950; Aggregation of axial parenchyma into bands and col Miller 1976; Meylan and Butterfield 1978; and Carl umns may, however, be an autapomorphy in Canaco quist 1991). myrica. These features are compatible with a myrica ceous placement for Canacomyrica. The similarity be 1. Scalariform perforation plates: Betulaceae (scalari tween Canacomyrica and Morella with respect to crys form with more numerous bars in Alnus, fewer in tals in rays and chambered crystals in axial Betula; Casuarinaceae (mostly simple plates, but parenchyma is striking. The absence of crystals in scalariform with up to 20 bars in sect. Leiopitys); Comptonia and Myrica s.s. contrasts with their pres Corylaceae (predominantly scalariform in Ostrya ence in Canacomyrica and Morella. and Ostryopsis, fewer than 20 bars in Corylus); Fa Presence of scalariform perforation plates and dif gaceae (occasionally scalariform in Fagus, other fuse axial parenchyma (and variations on diffuse pa wise characteristically simple); Juglandaceae (most renchyma) are doubtless symplesiomorphies for the ly simple except for a few bars in Alfaroa and En family, although reduction in number of bars per per gelhardtia, and typically several bars per plate in foration plate (most notable in Comptonia) is a prob Rhoiptelea); Nothofagaceae (plates simple and sca able apomorphy. The presence of dark-colored depos lariform within particular species, bars sometimes its in the wood, although not a striking feature, unites numerous in the scalariform plates); Ticodendra Myricaceae; Heterogeneous Type IJA or JIB rays are ceae (scalariform with many bars in the single spe characteristic of all genera but Canacomyrica. Tra cies). cheid dimorphism and the thin-walled nature of tra 2. Presence of tracheids as imperforate tracheary ele cheary elements in Myrica s.s., in which earlywood ments: Betulaceae (tracheids, fiber-tracheids); Cas contains numerous vessels but latewood consists of uarinaceae (tracheids, or fiber-tracheids plus vasi tracheids into which few or no vessels are interspersed, centric tracheids); Corylaceae (tracheids in late- are distinctive features that separate Morella from wood of Carpinus, Cotylus, and Ostrya, but fiber Myrica s.s. and are likely an autapomorphy in Myrica tracheids similar to the tracheids in earlywood); s.s. Other features of Myrica s.s. that differentiate it Fagaceae (vasicentric tracheids plus libriform fibers from Morella include greater grouping of vessels, in all genera except Fagus, which has fiber-tra shorter vessel elements, more numerous bars per per cheids); Juglandaceae (tracheids plus libriform fi foration plate, presence of tracheids in latewood but hers in Plalycarya, fiber-tracheids in other genera); fiber-tracheids in earlywood, predominance of uniser Ticodendraceae (Ticodendron, tracheids). iate rays, and absence of crystals. These two genera 3. Chains of cuboidal crystal-containing cells (cham are amply justified on the basis of wood features. bered crystals) in portions of axial parenchyma Comptonia is distinctive with respect to its large num strands: Casuarinaceae (Casuarina); Fagaceae ber of narrow vessels, change in tracheid wall thick (Castanopsis, Quercus); Juglandaceae (shorter ness with respect to position in growth rings, and ex chains or single cells in Carya and Engelhardtia, VOLUME 21, NUMBER I Myricaceae: Wood and Bark Anatomy 27

but long chains of chambered crystals in tropical condition, although that pathway does occur (e.g., Ros black walnuts); Nothofagaceae (some species of marinus of Lamiaceae, S. Carlquist, unpublished data). Nothofagus). The F/V ratio (see Table 1, column 14 for values 4. Diffuse and diffuse-in-aggregate axial parenchyma and definition) can be seen as an index of phyletic (other types may be present as well): Betulaceae advancement, because primitive imperforate tracheary (Alnus, Betula); Casuarinaceae (Casuarina); Cory elements (tracheids) are only a little longer than the laceae (Carpinus, Corylus, and Ostrya); Fagaceae vessel elements they accompany. Specialized imper (all genera); Juglandaceae (Juglans, some Engel forate tracheary elements (libriform fibers) are much hardtia species); Ticodendraceae (Ticodendron). longer than the vessel elements they accompany (Ca 5. Rays Heterogeneous Type I: Juglandaceae (some riquist 1975). Judged by this interpretation, Myrica species); Ticodendraceae (Ticodendron). Hetero ceae have rather primitive wood, an interpretation re geneous Type hA: Juglandaceae (some species). inforced by the presence in the family of features 1, Heterogeneous Type JIB: Casuarinaceae (Casuari 2, 4, and 5 cited earlier in this section. The F/V ratio na); Juglandaceae (some species). Families other is not, however; a precise measure of phyletic special than those listed above have rays that are homo ization, because other factors can be involved in this geneous (or nearly so). ratio (e.g., succulence). 6. Crystals in ray cells: Casuarinaceae (Casuarina); Juglandaceae (Carya, Engelhardtia, and Plalycar ECOLOGICAL CONCLUSIONS ya) have crystals in enlarged and subdivided ray cells as well as in ordinary ray cells). The degree of vessel grouping in Myncaceae is very low (Table 1, column 1). The only exceptions of note Myricaceae contain more primitive character states are in the two species of Myrica s.s., especially M. than any other fagalean family mentioned above ex harrwegii. Myricaceae are one more clear demonstra cept for Ticodendraceae, which are more primitive tion of the principle that in those dicotyledon families only in the scalariform perforation plates (which have with tracheids in wood, vessel grouping is minimal, more numerous bars and which retain pit membrane whereas more appreciable grouping occurs (to a pro remnants in many perforations). Thus, Myricaceae are gressively greater degree with greater xeromorphy) in rich in symplesiomorphies for Fagales. Most of the woods with fiber-tracheids or libriform fibers around features listed above are generally considered by wood vessels (Cariquist 1984). The earlywood of Myrica anatomists as indicative of primitive wood structure, gale and of M. hartwegii contains fiber-tracheids, so and are thus symplesiomorphies, which are not con that grouping of vessels is an advantageous conductive sidered by cladists as indicative of relationship. The safety device in earlywood. Latewood in these two distinctive modes of crystal occurrence shared by Myr species has tracheids, and thus, vessel grouping does icaceae and Juglandaceae probably represent syrlapo not occur in latewood. Indeed, there are few vessels in morphies, underlining the alliance of the two families latewood of these species: the tracheid is the conduc indicated in recent DNA analyses. tive cell type with optimal safety (resistance to em The retention of tracheids in many of the families bolism formation and to spread of embolisms). This is of Fagales listed above is interesting because the fea the physiological significance of the Type V growth ture occurs in Rosaceae also (Metcalfe and Chalk ring (Carlquist 1980, 2001). 1950), and thus is a symplesiomorphy including eu The range in vessel density might be expected to be rosids other than Fagales. From an ancestry based on approximately inverse to vessel diameter because of an all-tracheid background of imperforate tracheary el packing considerations. Deviations from such an in ements in secondary xylem, instances of vasicentric verse relationship do occur, however, as in lianas, in tracheids have developed in Fagaceae (vasicentric tra which greater vessel density probably is related to the cheids plus libriform fibers in all genera except Fa relative paucity of mechanical tissue in this growth gus), Casuarina (vasicentric tracheids plus fiber-tra form, in which stems are not self-supporting. In Myr cheids in a few species), and chaparral species of Pru icaceae, notable departure from the inverse relation nus (e.g., P. ilicifolia, P. lyoni) in Rosaceae (Cariquist ship occurs in Comptonia peregrina, in which vessels 1985; Cariquist and Hoekman 1985), These are inter are more numerous per mm2 than would be expected esting instances of tracheid dimorphism (Carlquist (e.g., the mean vessel diameter in C. peregrina is the 1988). Thus, libriform fibers (and in Casuarina, fiber same as that in M. gale, which has about a quarter as tracheids) are apomorphic in the species listed above many vessels per mm2). The elevated vessel density in as instances of vasicentric tracheid presence. As will C. peregrina may relate to its habitats, which are prob be shown in a study in progress, this pathway is more ably among the driest for Myricaceae. Although tra common than innovation of tracheids in a group with cheids in Coinptonia offer conductive safety, presence an axial wood background of libriform fibers as a basic of a very high number of vessels offers another form

1681

Angeles. and Los Berkeley with anatomy, wood ecological in concepts Further 1980.

Press, of

California

flora. University California A 1959. A. P p. MuNZ, 259 Los Angeles. and Berkeley Press, of California versity

23 1—280.

Gaz.

119:

(Craufordsville) Bot. Casuarinaceae. Uni evolution. of xylem strategies 1975. S. Ecological CARLQuIST,

the of

phylogeny and

anatomy 1948. M. F Comparative M0sELEY, 273—282. 28: Bot. J. rays. Amer. and uniseriate multiseriate the of

137:

368—377.

Gaz.

(Crawfordsville) Bot. Juglans.

Modification II. of dicotyledons. the in xylem rays of cialization

species of

of and

identification anatomy Wood B.

R. 1976.

MILLER, spe phylogenetic and development

ontogenetic The 1941.

250

Wellington. Z. N.

DSIR, 122,

Bull. DSIR

woods.

Zealand

9 18—928. 27: J. Bot. Amer. ray structure. Primitive

New structure 1978. The G.

B. A.,

BuTrERFIELD. AND

MEYLAN, I. dicotyledons. of in xylem the of

rays specialization genetic

297

Oxford. Press, Clarendon

troduction.

phylo and development The S. ontogenetic 1940. E. BARGH00RN,

in general of the conclusion and structure Wood Vol.

II.

edition,

36—60. Gaz. 58: Bot. the of Amentiferae. in certain

second of

dicotyledons, the Anatomy 1983.

AND

. reduction of

evidence Anatomical II. the angiosperms. logeny of

1500 Oxford. Press, dons.

Clarendon

phy the on Investigation 1914. SINNOTr. W. AND F. W., I. BAILEY,

of dicotyle

the Anatomy 1950. L. R., CHALK. C. AND

MErcALFE,

399—436. 141: Soc. J. Linneon Bot. APGH. plants: of flowering

84: J. 1407—1419. Rot.

families and the for orders Group classification Phylogeny

sperm

data.

Amer. plastid sequence

on based Hamamelididae “higher”

Angio of the update An 2003. II. GRouP

PHYLOGENY

ANGIOSPERM

of analyses Phylogenetic 1997. P K. 5., STEELE. P AND MANOS,

Oxford. Press, Clarendon 40B. cial Volume

CITED LITERATURE

Spe Systematics Association Hamamelidae. ‘Higher’ 2. Volume

Hamamelidae, the of history and fossil systematics, Evolution,

Society. Philosophical pp. American [eds.], S. and Blackmore Crane P In 147—165. Myricaceae,

the from of of relationships grant a and the aid The morphology 1989. A. with D. collected were Africa MACDONALD,

464. South from Morella of Samples Garden. Botanic bara

459— 4: Congr. Sci. Pac. Proc. Eighth

Pacifique. et

tico-Pacifique

Bar Santa at

accomplished was of

work

the

remainder

asia de fore Ia

remarquables deux Amentifères

1957. Sur

the acknowledged; gratefully is which Garden, Botanic

1162—1163.

Ana

Santa

Rancho the of facilities using the was done Sci. 229: Acad. Seances Rend. Hebd. Compi. des Myricaceae.

Ia de et florale of classification Ia work the morphologie 1949. De J.-F Much History. LERoY. Natural of Museum tional

557.

Na U.S. the of xylarium the from available samples

96: 547— Gaz. (Crawfordsville) Bot. of dicotyledons. rays

wood

made several

Yankowski

Stanley and

Mr.

Wisconsin,

in the

specialization of lines structural 1935.

Salient A.

KRms,

Madison, Laboratory, Products the of Forest

xylaria

200. 12: Novon Mesoamerica.

the from samples provided kindly Miller Regis in (Myricaceae) Dr. in Morel/a new 2002. combination A 5. KNAPP,

53: 993—995. Kew Bull. African Myricaceae. in combinations

ACKNOWLEDGMENTS 1998. New B. M. B., J. VERDc0uRT. P0LHILL, R. AND D. KJLLICK,

p. 185 Winterthur. Konkordia,

Buchdruckerei Verlagsanstalt anatomy. wood in used of terms

1998). Carlquist

glossary

1964. Multilingual COMMO-rEE IAWA NOMENcLATuRE. ON

Dubautia,

genus

Hawaiian of the species forest moist

1—338. 7: Univ. Arsskr. Uppsala uber Gefasspfianzen. nordische

(e.g.,

trees

and

shrubs forest cloud

tropical in pected Studien und systematische Nomenklatorische N. 1945. HyLANDER,

ex be would however, 1: J.. values, 1—265. suppl. high JAWA Such dicotyledons. difficult. is

of anatomy wood systematic of Bibliography M. 1994.

GREGoRY, habitats other those in with Myricaceae of species of

743 Louis, Missouri. St.

den,

values Ratio

Mesomorphy high the

rather

of parison

Gar

Botanical Missouri

and

Pretoria, Institute,

Botanical National

com

availability, moisture of kinds

various

exemplify

9. Strelitzia Plants. Cape 2000. F, J. AND MANNING. G0LDBLArr,

but of

rainfall, terms in define to easy are not ity) 14. 1—3 Bot. 58: Contrib. Smithsonian dicotyledons. of families

of the phylogeny and availabil evolution, 1986. Classification, A. water steady GOLDBERG, subsurface flats with or slopes

18. 305—3

52: Arb. Arnold J. States. United

streamsides; level; water of fluctuation with (swamps

the southeastern in of Myricaceae The genera 1971. S. T. ELIAs,

Myricaceae occupied

commonly

most habitats

York.

Press, New

University

Columbia plants. ering

the 1985). Because

Hoekman

and

(Cariquist

plants

of flow of classification system An integrated 1981. A. CR0NQuIsT,

Californian a southern few but for all those ns, 319—347. than 6: WA IA higher Bull., flora. California southern the woody

of anatomy wood Ecological 1985. A. D. H0EKMAN. is figure AND This 1250. is averaged, Myricaceae, studied

448 Heidelberg. &

Berlin

all for value definition) and values

for 15, column 1,

Verlag, Springer 2. Ed. anatomy, wood 2001. Comparative

Table (see

Ratio

The Mesomorphy as mesic. qualify

356—368. Sci. 52: Pac. radiation. to adaptive

in relation

that

features wood

have

Myricaceae Certainly 1978). Madiinae) (Asteraceae: Dubautia of anatomy 1998. Wood

al. et Sprent 1987; 96—104. Vitousek and Gard. 78: Bot. Missouri Turner Ann. 1970; on al. relationships.

comments of Ticodendron: anatomy and

bark 1991. Wood et Ryssen (Van observed been repeatedly has mycetes

103—118.

12:

A/iso elements.

tracheary

imperforate

by actino of Myricaceae

roots in fixation

Nitrogen

of evolution in new a

pathway dimorphism: 1988. Tracheid

conditions. nitrate in low resulting periods, prolonged

37—68. 11: A/iso tracheids. vasicentric of review

for

stands

water

where those including habitats, moist similar regions; and southern California of flora the woody nism in

mecha survival drought a as characterizes a tracheids whole as Vasicentric 1985. Myricaceae family The

525.

frost. and drought of times

505— 10: Aliso elements. tracheary imperforate to

and

relationship

in embolism resist

would

vessels)

latewood

mostly

significance woods:

dicotyledon

grouping

1984. Vessel

(presumably of them some that insure

would that sels

499—553. 9:

of ves redundancy a by providing safety A/iso evolution. of and conductive anatomy in wood work on recent comments

ALISO Cariquist 28 VOLUME 21, NUMBER 1 Myricaceae: Wood and Bark Anatomy 29

S0LTIs, D. E., P S. S0LTIs. M. W. CHAsE, M. E. M0RT, D. C. AL 1976. A phylogenetic classification of the Angiospermae. BACH, M. ZANIS, V. SAv0LAINEN, W. H. HAHN, S. B. HooT, M. F Evol. Biol. 9: 35—106. FAY, M. AxrELL, S. M. SwENsEN, L. M. PRINCE, W. J. KRuss, K. 2001. The classification and geography of the flowering C. NIXON, AND J. A. FERRIs. 2000. Angiosperm phylogeny inferred plants: dicotyledons of the class Angiospermae. Bot. Rev. 66:441— from 1 8S rDNA, rbcL, and atpB sequences. Bot. J. Linnean Soc. 647. 133: 381—461. TuRNER, D. R., AND P M. VIrouseK. 1987. Nodule biomass of the SPRENT, I. I., R. Scorr, AND K. M. PERRY. 1978. The nitrogen econ nitrogen-fixing alien Myrica fava Ait. in Hawaii Volcanoes Na omy of Myrica gale in the field. J. Ecol. 66: 657—668. tional Park. Pac. Sd. 41: 186—190. STERN, W. L. 1988. Index xylariorum. Institutional wood collections VAN RYSsEN, F W. J., AND N. GR0EBELAAR. 1970. The nodulating of the world. 3. IAWA Bull., n.s., 9: 203—252. and nitrogen fixing ability of South African Myrica species. S. SuNDBERG, M. D. 1985. Pollen of the Myricaceae. Pollen et Spores Afr. J. Sci. January: 22. 27: 15—28. Y0uNGKEN, H. W. 1919. The comparative morphology, taxonomy, TH0RNE, R. F 1968. Synopsis of a putatively phylogenetic classifi and distribution of the Myricaceae of the eastern United States. cation of the flowering plants. Aliso 6(4): 57—66. Contrib. Bot. Lab. Univ. Pennsylvania 4: 34 1—400.