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TAXON 31(3): 443-450. AUGUST 1982 WOOD ANATOMY OF DIPSACACEAE Sherwin Cariquist Summary Study of two species caceae features.

shows to features are related claimed Scabiosa shows that wood of to be allied to it, in having libriform in xylem of all Wood present study have tracheids, rather than Vestigial and in the family is

mediterranean-type climates in which the species studied Introduction The family Dipsacaceae exclusive of Morina consists of eight genera containing about 150 species (Willis, 1973).

1 TAXON 31(3): AUGUST 1982 WOOD ANATOMY OF DIPSACACEAE Sherwin Cariquist Summary Study of two species caceae features. is All of unusual, compared species of the Pterocephalus and three with families imperforate tracheary element type. dumetoruin secondary xylem pecially that of rays) Wood occur. shows to features are related claimed Scabiosa shows that wood of to be allied to it, in having libriform in xylem of all Wood present study have tracheids, rather than Vestigial and in the family is dry that the occur perforation plates are common primary of Dipsa several primitive fibers, as the Plerocephalus species. anatomy (es probably primitively woody, perhaps shrubby. mediterranean-type climates in which the species studied Introduction The family Dipsacaceae exclusive of Morina consists of eight genera containing about 150 species (Willis, 1973). These are Old World plants, distributed mostly in the Mediterranean and regions to the east, with a few species in tropical and southern Africa. Most species in the family are annual or perennial herbs; only a few are shrubs of a meter or more. Thus, only a few species are suitable for studies in wood anatomy. Metcalfe and Chalk (1950) include no data specifically on secondary xylem, although their data on vessels may well relate to secondary as well as primary xylem. Most phylogenetic systems group Dipsacaceae along with Valerianaceae and Ca lyceraceae, as families close to Asteraceae. Dipsacaceae are regarded as more spe cialized than most Asteraceae in one feature, the involucel which surround each flower. Dipsacaceae resemble Valerianaceac and Calycera ceae in having a single apical ovule; the ovule in Asteraceae epipetalous stamens in Dipsacaceae. The features in is formed from two bracts is basal. There are four which the families show resem blance are numerous, and the unanimity of opinion on their close relationships (a unanimity which makes detailed citation of various systems unnecessary) invites study of wood anatomy to see how endomorphic features integrate into the pattern. Dipsacaceae do have one feature relatively primitive for tubiflorous dicotyledons, presence of endosperm in mature seeds (Heywood, 1978). Solereder (1908) lists vessels with simple perforation plates and libriform fibers with simple pits as characteristics of Dipsacus laciniatus L. However, in Succisa pratensis Moench, he found that vessels have simply perforation plates except near primary xylem, and that imperforate tracheary elements have bordered pits, and thus would be termed tracheids in current terminology. Szabo (1905) found that in Knautia orientalis L., vessels have scalariform perforation plates, although other species of Knautia have simple ones. Szabo also found tracheids rather than libri form fibers in K. orientalis. Heywood (1978) notes that the perennial habitat caceae, but annuals have evolved several times is in basic in all genera of Dipsa dry habitats as parallel lines of Claremont Graduate School, Pomona Claremont, CA 91711, U.S.A. College, and Rancho Santa Ana Botanic Garden, AUGUST

specialization, especially in Cephalaria, Knautia, Pterocephalus, and Scabiosa. Data from wood anatomy are essential in assessing this phylogenetic claim.

2 specialization, especially in Cephalaria, Knautia, Pterocephalus, and Scabiosa. Data from wood anatomy are essential in assessing this phylogenetic claim. The availability of wood samples more than 1 cm in diameter for five species of the family has permitted a more complete picture of wood anatomy in the family than hitherto possible, making possible conformation or extension of trends noted above. The wood samples studied belong to Pterocephalus and Scabiosa, genera closely related within the family for which wood data has not previously been pub lished. Pterocephalus dumetorum Coult. (Carlquist 2600, RSA) was collected on Roque Nublo on the summit area of Gran Canaria, Canary Islands: photographs of this plant can be seen in Carlquist (1974). Pterocephalus lasiospermus Link (Carl quist 2694, RSA) was collected in subalpine scrub in the Caldera del Teide, Tenerife, Canary Islands. The specimen of Scabiosa variifolia Boiss. was obtained from a plant grown at the University of California, Santa Barbara (Ferren & Bleck 2360, RSA, UCSB); this shrub is a native of the island of Rhodes. Scabiosa africana L., a native of South Africa, was likewise obtained from a cultivated specimen in the Melbourne Botanic Garden (Carlquist 1079, RSA). The specimen of S. cretica L. was obtained on Crete, and comes from the wood collection of the U.S. National Museum (USw-49241); the species occurs on Crete and Sicily. Acknowledgment is expressed to the institutions named for the specimens of Scabiosa. Sections and macerations were prepared according to the usual techniques. Results Growth rings are variously developed in Dipsacaceae, ranging from little evident in Scabiosa africana (Fig. 1) to moderate in Pterocephalus dumetorum (Fig. 10) and P. lasiospermus, to rather well marked in Scabiosa cretica (Fig. 3) and S. varitfolia. The moderate growth rings would correspond to Type lb in my (1980) classification; the S. cretica rings would be Type VD, and the S. variifolia rings would be Type VB. These growth ring types correspond to the summer dry winter wet climatic regimes from which these specimens come. The fact that the specimen of S. africana was cultivated might account for lack of growth rings in that wood. Vessel elements in the Dipsacaceae studied here have predominantly simple per foration plates in secondary xylem, although primary xylem was in each case ob served to have scalariform perforation plates. Such conditions can be found in a number of dicotyledonous families, such as Gesneriaceae and Scrophulariaceae (Bierhorst and Zamora, 1965). In Pterocephalus dumetorum, however, about 20 per cent of perforation plates in secondary xylem have one of the types shown in Figs Perforation plates consisting of two or three circular perforations per end wall, well separated (Figs. 12, 13) are not truly scalariform, but may be grouped with scalariform types. Both the frequency and morphology of these plates in P. dumetorum and the fact that they represent types intermediate between scalariform and simple suggest that one must interpret these plates, like those in Knautia on entalis, as valid vestiges of a scalariform condition. The presence of scalariform plates in primary xylem, a refugium of primitive features for any given phylad (Bailey, 1944) is an additional reason for this interpretation. Vessel elements in Pterocephalus lasiospermus have spiral thickenings and helical grooves (Figs. 7 9). This seems to correspond to the subalpine habitat for this species, in accordance with the generally xeromorphic distribution of this charac teristic (Carlquist, 1980). The dimensions of vessel elements in Dipsacaceae and their density per sq. mm. of transection correspond quantitatively to data collected in Asteraceae (Carlquist, 1966), probably because the ecology of these Dipsacaceae represents a range similar to that of the habitats of most Asteraceae, which often tend to be found in dry areas. Tracheids are the imperforate tracheary elements of the Dipsacaceae studied here. Counterstaining wood sections with a safranin-fast green combination permitted easy 444 TAXON VOLUME 31

identification of borders on pits of the tracheids (Fig. 7). In some pits, the apertures extend beyond the circular outline of the pit cavity, but the borders are fully de veloped, never vestigial.

3 identification of borders on pits of the tracheids (Fig. 7). In some pits, the apertures extend beyond the circular outline of the pit cavity, but the borders are fully de veloped, never vestigial. Persistence of tracheids in a group with such specialized floral structure as Dipsacaceae is noteworthy. Among putatively related families in various classification systems, all have libriform fibers with the exception of Good eniaceae, which have fiber-tracheids and tracheids as imperforate element types (Cariquist, 1969). In a group which occupies dry habitats, there is an advantage of retention of tracheids, because tracheids can localize air embolisms likely to occur under water stress and thereby lessen disabling of the conductive tissue. Thus, a suprising number of Mojave Desert shrubs have tracheids as the imperforate tra cheary element type (Carlquist, 1980), and the occurrence of this wood plan in Dipsacaceae, which are distributed chiefly in mediterranean-type climates, seems understandable. Wide multiseriate rays occur in Scabiosa africana (Fig. 2), but rays are only moderately wide in most Dipsacaceae (Figs. 4, 6, 11). Rays consist of relatively thinwalled cells which are lignified (Figs. 12, 13). Bordered pits were observed in a few ray cells of the species studied here. Perforated ray cells were frequent in Ptero cephalus dumetorum (Figs. 12, 13). The multiseriate portion of multiseriate rays consists of procumbent cells, but sheathing cells are erect, and some multiseriate rays have uniseriate wings (Figs. 4, 6, 12) which are composed of erect ray cells. Uniseriate rays also are composed of erect ray cells. The similarity of uniseriate rays to uniseriate wings of multiseriate rays is noteworthy, and connotes a morpho genetic correlation. Unisenate rays are abundant enough so that attachment of uni senate strands of ray cells to tips of multiseriate rays as uniseriate wings becomes highly likely. The presence of erect ray cells in multiseriate rays is not exceptional, so paedo morphosis is not represented in the species studied, in my opinion. If the five species studied are typical of the family, wood structure of Dipsacaceae appears to be ba sically like that of a shrubby family, and the phylogenetic scenario of Heywood (1978) seems probable. Two families closely related, Valerianaceae and Calycera ceae, would seem to have at least some rayless woods, judging from the descriptions of Solereder (1908). Raylessness suggests phylesis toward a woodier habit from an herbaceous ancestry in many instances (Carlquist, 1970). Of the species included in this study, only Scabiosa africana has crystals in ray cells (Fig. 5). The crystals are uniformly rhomboidal, one per cell, and present in virtually every ray cell in that species. Crystals in wood cells of Dipsacaceae have not been previously mentioned. Cluster crystals are reported for primary stem cortex of Dipsacaceae by Metcalfe and Chalk (1950). Quantitative Wood Data Pterocephalus durnetorum. Vessel elements 307 per sq. mm. of transection; mean diameter 41 ibm; mean length 338 m. Mean tracheid length 585 m. Mean uniseriate ray height 214 m; mean multiseriate ray height 784 m. Prerocephalus lasiospermus. Vessel elements 284 per sq. mm. of transection; mean diameter 39 sm; mean length 217 m. Mean tracheid length 392 m. Mean uniseriate ray height 132 jsm; mean multiseriate ray height 1388 sm. Scabiosa africana. Vessel elements 180 per sq. mm. of transection; mean diameter 65 m; mean length 284 sm. Mean tracheid length 509 sm. Mean uniseriate ray height 190 m; mean multiseriate ray height 1058 sm. Scabiosa cretica. Vessel elements 211 per sq. mm. of transection; mean diameter 43 m; mean length 292 m. Mean tracheid length 527 m. Mean uniseriate ray height 217 sm; mean multiseriate ray height 442 sm. Scabiosa variifolia. Vessel elements 383 per sq. mm. of transection; mean diam AUGUST

eter 35 jim; mean length 295 jim. Mean tracheid length 514 jim. Mean uniseriate ray height 258 jim; mean multiseriate ray height 460 jim. References Bailey, I. W. 1944.

4 eter 35 jim; mean length 295 jim. Mean tracheid length 514 jim. Mean uniseriate ray height 258 jim; mean multiseriate ray height 460 jim. References Bailey, I. W The development of vessels in angiosperms and its significance in mor phological research. Amer. i. Bot. 31: Bierhorst, D. W. and P. M. Zamora Primary xylem elements and element associations of angiosperms. Amer. J. Bot. 52: Carlquist, S. Wood anatomy of Compositae: a summary, with comments on factors controlling wood evolution. Aijso 6(2): Wood anatomy of Goodeniaceae and the problem of insular woodiness. Ann. Missouri Bot. Gard. 56: Wood anatomy of insular species of Plantago and the problem of raylessness. Bull. Torrey Bot. Club 97: Island Biology. Columbia University Press, New York Further concepts in ecological wood anatomy, with comments on recent work in wood anatomy and evolution. A/iso 9: Heywood, V. H., ed Flowering Plants of the World. Mayflower Books, New York. Metcalfe, C. R. and L. Chalk Anato, ny of the Dicotyledons. Clarendon Press, Oxford. Solereder, H Systematic Anato,nv of the Dicotyledons (trans. by L. A. Boodle and F. E. Fritsch, rev, by D. H. Scott). Clarendon Press, Oxford. Szabo, Z. von Monographie der Gattung Knautia. Bot. Jahrb. 35: Willis, J. C A Dictionary of the Flowering Plants and Ferns (rev, by H. K. Airy Shaw). Cambridge University Press, Cambridge. i 446 TAXON VOLUME 31

5 q Figs Wood sections of Scabiosa. 1 2: Scabiosa africana, Carlquist I: Tran section. Weakly differentiated growth ring begins in top quarter of picture. 2: Tangential sec tion. Notably wide multiseriate rays evident. 3 4: Scabiosa cretica, USw-4924l. 3: Transec tion. Growth ring begins in upper third of photograph. 4: Tangential section. Rays narrow. Figs. 1 4, magnification scale above Fig. 1 (finest divisions = 10 sm). AUGUST

I Figs. 5 9. Wood sections of Dipsacaceae.

6 9: Pterocephalus lasiospermus, Carlquist 2694. 6: Tangential section of wood.

7: Vessels at left and right; between vessels, tracheids showing bordered pits.

6 I Figs Wood sections of Dipsacaceae. 5: Scabiosa africana, Carlquist 1079, crystals from radial section. 6 9: Pterocephalus lasiospermus, Carlquist : Tangential section of wood. Erect ray cells prominent. 7 9: Radial sections of wood. 7: Vessels at left and right; between vessels, tracheids showing bordered pits. 8, 9: Vessels showing helical thickenings. Fig. 5, 7 9, scale above Fig. 5 (divisions = 10 sm). Fig. 6, scale above Fig. I. 448 TAXON VOLUME 31

Figs. 10 13. Vessels notably narrow rays.

showing ray cell ray cell; Fig. 12 diameter.

10: and of wing of multiseriate ray; two in wall. Figs.

7 Figs Vessels notably narrow rays. 12: Radial cells, center top. Fig. 1. Fig. 12, Pterocephalus dumetorum, Carlquist section, 13: in 11: showing ray cell ray cell; Fig. 12 diameter. Perforated scale above : and of wing of multiseriate ray; two in wall. Figs. 10, 11, = 10 Fig. 13, Fig. 5. Wood sections. Tangential section, showing multiseriate types bordered pits present gm). (divisions scale above Transection. uniseriate perforate ray scale above AUGUST i

p Figs. 14 2 I. Plerocephalus dumetorum, Carlquist 2600. Perforation plates of vessels from radial sections of wood.

17: Plate with only portions of bars, irregular perforation outline. 18: A double perforation plate, the lower portion pit-like.

8 p Figs I. Plerocephalus dumetorum, Carlquist Perforation plates of vessels from radial sections of wood. 14: Plate with three wide, bordered bars. 15: Plate with three slender bars. /6: Plate with seven bars. 17: Plate with only portions of bars, irregular perforation outline. 18: A double perforation plate, the lower portion pit-like. 19: Plate with two bars, left; simple elliptical plate, right. 20: Pair of perforations on end wall of vessel element. 21: Plate with portion of a bar. Figs , magnification scale above Fig TAXON VOLUME 31

WOOD AND BARK ANATOMY OF. Rancho Santa Ana Botanic Garden and Department of Biology, Pomona College Claremont, California 91711

WOOD AND BARK ANATOMY OF. Rancho Santa Ana Botanic Garden and Department of Biology, Pomona College Claremont, California 91711 ALISO 12(3), 1989, pp. 485-495 WOOD AND BARK ANATOMY OF DEGENERIA SHERWIN CARLQUIST Rancho Santa Ana Botanic Garden and Department of Biology, Pomona College Claremont, California 91711 ABSTRACT Wood anatomy