Aliso: A Journal of Systematic and Evolutionary Botany Volume 8|Issue 1 Article 15 1973 An Anatomical and Morphological Study of Datiscaceae Christopher Davidson Rancho Santa Ana Botanic Garden, Natural History Museum of Los Angeles County Follow this and additional works at:http://scholarship.claremont.edu/aliso Part of theBotany Commons Recommended Citation Davidson, Christopher (1973) "An Anatomical and Morphological Study of Datiscaceae,"Aliso: A Journal of Systematic and Evolutionary Botany: Vol. 8: Iss. 1, Article 15. Available at: http://scholarship.claremont.edu/aliso/vol8/iss1/15 ALISO VoL. 8, No. 1, pp. 49-110 JULY 17, 1973 AN ANATOMICAL AND MORPHOLOGICAL STUDY OF DATISCACEAE1 CHRISTOPHER DA VIDSON2 Rancho Santa Ana Botanic Garden Claremont, California 91711 INTRODUCTION The Family Datiscaceae contains three genera and four species. Octomeles and Tetrameles are monotypic genera of tall trees in the Old World tropics. The former is common in riverine rain forests of Malesia; the latter grows in different types of monsoon forests from New Guinea to India. The genus Datisca has a Mediterranean-Californian disjunction, and the two species are herbaceous perennials 6-10 ft tall. Datisca glomerata ( Presl) Baill. ranges from the Sierra San Pedro Martir of Baja California to n01thern California and occurs at elevations from 200 to 6,500 ft, depending roughly on. the latitude ( Fig. 1). A typically riparian species, it can be found in sandy soil along waterways in a variety of Quercus woodlands and coniferous forests in the coast ranges and on the eastern and western sides of the Sierra Nevada Range. Genera com monly found with D. glomerata are Alnus, Fraxinus, Rhus, Ribes, and Salix. Datisca cannabina L. occurs on the southern slopes of the western Hima layas in India, Kashmir, Pakistan, and Afghanistan and in the southern part of Tadzhik S. S. R. The most eastern collection sites in Iran are in the Elburz Mountains, and from this area the range extends westward through the Middle East, and Turkey to Crete ( Fig. 2). The apparent disjunction in the range in eastern Iran may be the result of inadequate collections or bibliographic oversight. Because there was no opportm1ity to vist European herbaria during this study, the map is based mostly on published records. If no specimen has been collected there so far, the species may yet be fom1d in this region, because the Turkmen-Khurasan ranges form an almost con tinuous chain from the eastern end of the Elburz Mountains to Afghanistan. Datisca cannabina occurs at elevations of 1,000-6,000 ft in a broad range of riparian habitats similar to those of D. glomerata. Associated plants in 1 Based on a dissertation submitted to the Faculty of The Claremont Graduate School in partial fulfillment of the requirements for the degree of Doctor of Philosophy, May, 1972. 2 Present address: Musewn of Natural History, County of Los Angeles, 900 Exposition Blvd., Los Angeles, Calif. 90007. [ 49] 50 ALISO [VoL. 8, No. 1 DATISCA GLOMERATA (PRESL) BAILL. Fig. 1. Distribution of Datisca glomerata.-A. California.-B. Baja California. Scale slightly greater than in map A.-Dots represent specimens seen in the following herbaria: CAS, DAV, DS, JEPS, POM-RSA, UC. JULY 1973] DAVIDSON: DATISCACEAE 51 Turkey include Quercus coccifera L. and Fontanesia phillyreoicles Labill. (Davis, 1949); and in Afghanistan, Quercus baloot Griff. and Ceclrus cleoclara ( Roxb.) Loud. ( Kitamura, 1960). Although D. cannabina has long been used in these areas as a source of yellow dye for wool and silk, its range is certainly natural and not the result of transportation by man. Tetrameles nucliflora R. Br. is a common to infrequent component of monsoon forests from Australia, eastern Papua, and New Guinea through the Lesser and Greater Sunda Islands ( except Borneo), southeast Asia, Assam and Bengal, the Western Ghats of India, and Ceylon (Fig. 3). The length of the dry season in these areas may vary from five months in Assam to one or two months in eastern Sumatra and western Java, where the tree is uncommon. Abundance increases northward on the Malay Peninsula into Thailand and Indo-China. Limestone soils are the preferred substrate throughout the range; for instance, on Peutjang Island of the west coast of Java, Tetrameles is on saturated, coral-derived soil left by the great tsunami of 1883. The high water table is not present all year long. A similar habitat is found on Timor and presumably on the rest of the Lesser Sw1das ( Drees, 1951; Kartawinata, 1965). In Viet Nam it is considered a limestone indicator (Ngan, personal communication, 1970). As a member of the Tetrameles Stereospermum-Ceclrela formation, it occurs in parts of the Assam Valley ( Rowntree, 1954), and in other types of forest up to 2,000 ft in Bhutan and Sikkim. Tetrameles and Octomeles grow within a few miles of one another in several places where strips of riverine rain forest cut through predominately evergreen or wet deciduous forest having a short dry period; for example, the Brown River area in Papua ( Fig. 7). The dry period need only be long enough for Tetrameles to lose its leaves and set buds. The rainfall in this region is around 80 in. a year. The soil is described as neutral olive stratified, poorly drained, and probably alkaline. Ordinarily Octomeles sumatrana Miq. tends to form -gregarious stands along rivers and streams up to 2,000 or 3,000 ft, but it is never found in the mangrove zone ( Fig. 4). Sometimes b·ees occur in ravines in prin1ary and secondary dipterocarp forest in Borneo where they are not directly as sociated with a water course, however. It also commonly sprouts up in regrowth following agricultural clearing, along with pioneers like Antho cephalis caclamba ( Roxb.) Miq., Pterospermum, and bambusoid grasses. When not gregarious, it is mixed with riverine Dipterocarpaceae ( Browne, 1955, pp. 10, 82). In southern Papua ( Fly River), where the narrow belts of riverine vegetation are bordered by monsoon forest, the associates are Sonneratia caseolaris ( L.) Engl., Terminalia, Livistona, and Nypa fruticans Wurmb. (Royen, 1963). Both trees attain great heights. Octomeles grows from 25 to 35 m in 4-10 years and reaches 60 m as a maximum ( Fig. 5). The straight bole occupies 50-60% of the total height. A tree in the botanic garden at Bogor, Indonesia, outside the natural range, grew to 25 m with a dbh of 47 cm in £om years ( Koopman and Verhoef, 1938). On young trees the buttresses are only 2-3 m high, but on older ones they extend up to 6 rn. Tetrameles has a sinuous 52 ALISO [VoL. 8, No. 1 0 2 ~ DATISCA CANNABINA L. 0 0 () .. • • 3 TETRAMELES NUDIFLORA 4 OCTOMELES SUMATRANA MIQ. JULY 1973] DAVIDSON: DATISCACEAE 53 bole ( Fig. 6, 7) and grows to 50 m. In wet areas individuals may be no taller than surrounding trees, but in dry areas they are widely spaced emergents, for instance in Assam and even in central Malaya ( Pahang). In the Western Ghats the tallest trees of this species are about 30 m, and they often branch only 12 m above the ground ( Santapau, 1953). The tree in Fig. 6 branched about 12 m above the 5 m buttresses and showed a clock wise branching spiral. Buttresses are frequently up to 6 m high ( Fig. 8), but those on the 50-m tree in Fig. 7 were only 2.5 m. Datisca was first discovered in Crete in the 1590's by a physician, Honorius Bellus, who sent plants to Italy for cultivation ( Bauhinius and Cherlerus, 1651, pp. 466-467). In the following years it was described and illustrated by a swarm of herbalists, who were familiar with the unisexual flowers and the yellow dye in the roots; and Linnaeus himself ( 1760) commented on the possibility of parthenogenetic formation of its fruits. According to Hasskarl ( 1866) the Palacca in Rumphius' Herbarium Amboinense ( 174 3, vol. 3, p. 195, t. 125) is actually Octomeles. The illustra tion apparently represents the capsule valves on an old inflorescence axis, and mention of such an axis is made in the text. The rest of the description corresponds to Octomeles, although sometimes in a general way only, in cluding a rank odor of leaves, domatia in the leaf-vein axils, and red veins on the leaf underside. Several discrepancies stand out, however: the bark of Palacca is fissured and the young petioles ( ? ) are sticky. After the ac count of the fruit valves, which is accurate, Rumphius mentions some light yellow flowers in wide-spreading bunches and long fruits like those of "Canna fistulosa." There is just enough confusion here to prevent certainty, but Octomeles is probably what he had in mind. The tree was otherwise botanically unknown until 1861, when Miquel described it from Sumatra. Even today very little is known about the family. Most of the work on these plants has been of very limited scope, and the systematic implications have been unclear. One of the objectives of this study has been to present an intrafamilial comparison of the three genera. They are, in fact, closely related, although there have been attempts to segregate the two trees as a separate family. A second objective has been to contribute to a better understanding of the relationships of the family within the Cistales of Thorne ( 1968) or Violales of Cronquist ( 1968). The latter may seem too ambitious because this study, though comparative, is certainly not compre hensive: several interesting and important subjects, such as embryology and root anatomy, are treated briefly or neglected. Nonetheless, from this vantage point, certain relationships seem clear. These will be discussed in the "Conclusions" section, along with a few comments on the distribution and taxonomic history of the family. ~ Fig. 2-4. Distribution of Datiscaceae, except Datisca glomerata.- 2. Datisca cannabina. -3. Tetrameles mi.diflora.-4. Octomeles sumatrana.-Dots represent specimens seen in the following herbaria: BO, CAS, DAV, DS, JEPS, KEP, LAE, PNH, POM-RSA, SAN, SING, UC. Circles represent records published in standard floras. 54 ALISO [VoL. 8, No. 1 Fig. 5-8.--4. Octomeles sumatrana. Tree ca. 50 m, near Markham R., New Guinea.- 6-8. Tetrameles nu.d·iflora.-6. Tree on Langkawi Is., W. Malaysia. Note clockwise branching spiral.-7. Tree ca. 50 m, near Brown R., Papua.-8. Buttress on Langkawi Is. tree shown in Fig. 6; ca. 6 m high. JULY 1973] DAVIDSON: DATISCACEAE 55 MATERIALS, METHODS, AND ACKNOWLEDGMENTS Materials of Datisca glomerata were collected in the wild in California except for seedlings, which were grown in the greenhouse at Rancho Santa Ana Botanic Garden, Claremont, California. The following collections are cited in the text or with the illustrations: Davidson 1002, Topanga Canyon, Los Angeles County; Davidson 1557, San Gabriel Mts., Los Angeles County; Gettinger 933, Forks of Salmon, Siskiyou County. Datisca cannabina was grown from seed obtained from the botanic gardens in Cambridge, England; the University of Graz, Austria; and the University of Warsaw, Poland. Samples of Octomeles and Tetrameles were collected during a field trip to Malesia in 1970. Collection data for Octomeles is as follows: Davidson 1124, sapling, Gum Gum F. R., Sabah; Davidson 1126, 1127, seedlings, Lungmanis, Sabah; Davidson 1128, tree, Lungmanis, Sabah; Davidson 1482, tree, New Guinea. Data for Tetrameles: Davidson 1413a, tree, Malaya; Davidson 1413b, sucker shoots on stump, Malaya; Davidson 1469, tree, Java; Davidson 1493, tree, Papua. Flowers, vegetative material, phloem, and cambium were preserved in alcohol. Male flowers of Tetrameles were not collected. W o·od specimens were taken across the diameter of the bole at a level just above the buttresses, at mid-point 10-30 m above the ground, and at a level below the first branching. Samples from buttresses, limbs, and twigs were also included. Woods were kiln-dried and shipped to the U.S. with paraformaldehyde flake as a preservative. Male and female flowers of Octomeles ( SAN 59701, SAN 59702, SAN 62084) supplied by Mr. P. F. Cockburn of the Forest Department, Sabah, have been used when necessary. The seedlings of Octomeles were grown at Lungmanis, Sabah, and were given to me by Mr. Bob Bragan of the U.S. Peace Corps. They were of two types. One was grown in the sun ( Davidson 1127) and the other, in the shade ( Davidson 1126). The shade-grown seedlings were much more robust than the ones given full sun. Voucher specimens for plants used in this study are deposited in the herbarium at Rancho Santa Ana Botanic Garden. All material was prepared by standard microtechnical procedures. Woods of the two trees sectioned poorly on the sliding microtome and had to be embedded in parowax. Phloem was stained with safranin-fast green and with lacmoid, following the procedure of Cheadle et al. ( 1953). Observa tions on ergastic substances in Octomeles and Tetrameles were made on hand-sectioned, preserved material; but in Datisca fresh material was used. Phloroglucinol-HCl was used as an indicator of lignin. Pollen of Datisca was fresh; that of Octomeles was preserved. Fiber measurements were taken from macerations, but vessels were too large to macerate well and had to be studied in tangential sections. All figures represent the average of 50 measurements. Pollen measurements were taken from photographs. I am particularly indebted to my advisors, Dr. R. F. Thorne and Dr. Sherwin Carlquist, for their invaluaible advice and assistance. Field work would have been impossible without the aid of the following people: Mr. P. F. Cockburn (Sabah); Mr. W. F. Null, Dr. E. Soepadmo, and Mr. Low 56 ALISO [VoL. 8, No. 1 Fong Choong (W. Malaysia); Dr. A. J. G. H. Kostermans and Dr. M. A. Rifai (Indonesia); and Mr. J. S. Womersley (New Guinea). Mr. Leonard Hancock of the Chevron Oil Field Research Co. prepared the scanning EM photographs, and Dr. J. S. Henrickson arranged to have the transmission EM work done. Finally, I am grateful to the trustees of the Rancho Santa Ana Botanic Garden for provision of laboratory facilities. ANATOMICAL AND MORPHOLOGICAL OBSERVATIONS FLORAL MORPHOLOGY 0ctomeles.-Male and female flowers of 0ctomeles are sessile and linearly attached on long, axillary spikes ( Fig. 9A). The spikes are pendant and unbranched; and they may reach a length of up to one-half meter, although axes bearing male flowers are often somewhat longer than those bearing females. Commonly a single axis may bear over 100 flowers. The female flower develops into an essentially tubular ovary that is surmounted by a "crown" composed of the inner nectary cup, the perianth tube, and the styles ( Fig. 11). Petals are absent. Styles are opposite small calyx lobes and are terminated by capitate or peltate stigmas. The numerous ovules are borne on 6-8 placentae that are cuneiform in transection and alternate with the styles. In fruit the ovary enlarges from 3 or 4 mm to 6 or 8 mm in diam and reaches 12-13 mm in length ( Fig. 10). Dehiscence is longitudi nal. The perianth tube of the male flower bears calyx teeth 2-3 mm long alternating with petals 3-4 mm long ( Fig. 12). Both whorls are valvate in bud. The inner cup is lined with a large nectary, on the rim of which the stamens are borne. The 6-8 filaments are opposite the calyx teeth and carry basifixed anthers that are folded abaxially over the filament tip. At anthesis the stamens expand to a length of 15-16 mm. Typical 0. sumatrana Miq. occurs in Sumatra and Borneo ( Fig. 11). It has flower parts in 6's and Ts and has obtuse to subcordate, ovate leaves. Warburg ( 1891) described 0. moluccana from the Philippines, Celebes, and New Guinea and proposed that it differed from 0. sumatrana Miq. pri marily in having floral parts in 7's ( occasionally in 6's), but never in S's, and in having round-cordate rather than ovate-cordate leaves ( Fig. 9, 10). Because flowers seen in this study from both Borneo and New Guinea were mostly hexamerous and heptamerous, only rarely octomerous, this distinc tion between the two cannot be upheld. It has not been accepted in the most recent treatment of the family for Flora Malesiana ( Steenis, 1953). Tetrameles.-Female flowers of Tetrameles are sessile on pendant, branched axes ( Fig. 13). As in 0ctomeles, a tiny bract subtends one, two, or more floral primordia on a young inflorescence. The inflorescence axes are in the axils of finger-like bracts and are grouped at the tips of leafless branches from which they spring at the start of the rainy season. Branches in the flowering axes are also subtended each by a tiny bract. The tetramerous or occasionally pentamerous female flowers are 3-4 mm long and 2.5-.3 mm JULY 1973] DAVIDSON: DATISCACEAE 57 Fig. 9-12. Octomeles sumatrana.- 9. Davidson 1482. A. Inflorescence with female flowers, x¼. B. Capsules of an old inflorescence, x%.-10. Davidson 1482. Fruit. Circles represent peltate trichomes.-11. SAN 62084. Female flower. Peltate trichomes not shown.-12. SAN 59702. Male flower ( Fig. 10-12 drawn to same scale.) in diam ( Fig. 14). The crown is not as pronounced as it is in Octomeles, and there appears to be no nectary. Styles are opposite the sepals and bear grooved, spatulate stigmas. Petals are missing. Ovules develop on placental ridges that alternate with the styles, as in Octomeles and Datisca. In fruit the ovary becomes globose, with a diameter of 4-4.5 mm (Fig. 15). De hiscence is by means of an apical pore formed when the four lobes separated by the prominent sutures at the top of the ovary dry and bend downward toward the locule. A similar process occurs in Datisca. Axes bearing the male flowers of Tetrameles are shoiter than those of the females and are somewhat more rigidly spreading at the branch ends. Steenis ( 1953) calls them panicles and says the male flowers are slightly fragrant. The male flowers have short calyx tubes and are tetramerous like female flowers. There are in some instances a few weakly developed lobes alternating with the sepals, but for the most pait petals are absent. Stamens are on the rim of the inner cup opposite the sepals. The anther is basifixed and dehisces longitudinally ( Fig. in Steenis, 1953, p. 386). Datisca.-Inflorescences of Datisca are greatly shortened so that the flowers are axillary on the main axis or on lateral branches ( Fig. 16). At the base of a lateral branch, flowers of D. cannabina may be pedicellate on very