Cecropiaceae a new family of the Urticales r* C.C. Berg Summary Mora- The problem of the correct position of the Conocepbaloideae, a subfamily of the transferred the Urticaceae Corner be satisfac- ceae in Engler's system, but to by (1962), can this be named torily solved by assigning the rank of family to taxon, to Cecropiaceae. of and the six this ( Diagnoses a key to genera constituting family Cecropia, Coussapoa, Musanga, Myrianthus, Poikilospermum, and Pourouma) are given. The classification of the Urticales and the relationship between the Cecropiaceae and both Moraceae and Urticaceae A are discussed. key to the families of the Urticales is given. Cecropiaceae C.C. Berg fam. nov. Type genus: Cecropia Loefling Cecropieae Gaudichaud in Freycinet, Voy. Uranie, Bot. 491, 506. 1830, as tribe of the Urticeae (= Urticales) Pouroumeae Gaudichaud in Freycinet, Voy. Uranie, Bot. 491, 511. 1830, as tribe of the Urticeae (= Urticales); Trecul, Ann. Sci. Nat. Bot. III. 8; 77. 1847, as tribe of the Artocarpeae (= Moraceae s.l., p.p.); Miquel in Martius, FI. Bras. 4 (1): 83, 122. 1853, as subtribe of the Artocarpeae (= Moraceae s.l., p.p.). Conocephaleae Trecul, Ann. Sci. Nat. Bot. III. 8: 77. 1847, as tribe of the Artocarpeae (= Moraceae s.l., p.p.); Miquel in Martius, FI. Bras. 4 (1); 83, 131. 1853, as subtribe of the Artocarpeae (= Moraceae s.l., p.p.); Bureau in De Can- dolle, Prodr. 17; 280, 283. 1873, as tribe of the Artocarpaceae (= Moraceae s.l., p.p.); Bentham & Hooker, Gen. PI. 3 (1): 343. 1880, as tribe of the Urticaceae (= Urticales). Conocepbaloideae Engler in Engler & Prantl, Nat. Pflanzenfam. 3 (1); 93. Urticaceae 1889, as subfamily of the Moraceae sensu Engler, transferred to the by Corner, Card. Bull. Singapore 19: 251. 1962. For a historical review of the subdivisions of the Urticales the reader is referred to Chew Wee-Lek, Card. Bull. Singapore 20 (1): 22. 1963. Arbores vel frutices semper dioeci, radicibus aeriis vel gralliformibus; systema ductuum laticiferorum reductum, laticem baud exudans. Folia spiraliter dis- posita, integra vel plus minusve profunde palmato- vel radiato-incisa; stipulae vel vel connatae. Inflorescentiae cymoso-ramosae capitatae glomerulum digita- efformantes. staminati liberis vel tum spicarum Flores tepalis 4-2, connatis; stamina 4-1, recta, interdum inflexa et gradatim porrigentia, sed non elastice eflectentia; pistillati tepalis 4-2, connatis; stigma ligulatum, capitato-penicillatum basale vel subbasale; vel vel peltatum; ovulum (sub)orthotropum, semen parvum endospermum adest vel abest. magnum;embryo simplex, rectus; Terrestrial or hemi-epiphytic woody plants with aerial roots or stilt-roots and Leaves with a reduced system of latex tubes. spirally arranged, pinnately veined to subtriplinerved or to palmately veined in entire to palmately incised leaves or fused, radially veined in peltate leaves; stipules mostly fully amplexicaul; cysto- liths present in Poikilospermum, lacking in the other genera.' Plants strictly * Institute of Systematic Botany, Heidelberglaan 2, Uithof, Utrecht, Netherlands. 39 FEBRUARY 1978 dioecious, inflorescences unisexual, the staminate ones cymosely branched, the pistillate ones cymosely branched, capitate, spicate, subumbellateor both stami- nate and pistillate inflorescences forming a pedunculate digitate cluster of spikes enveloped by a caducous spathe. Staminate flowers with 4-2 free or fused tepals, stamens 4-1, straight in the bud, sometimes inflexed, but then straightening distinct gradually at anthesis; a pistillode mostly lacking. Pistillate flowers with a tubular, 4-2-lobed to 4-2-dentate perianth, ovary free, stigma 1, lingulate to capitate-penicillate to peltate, ovule (sub)orthotropous, basal or subbasal. Fruit small and free or large and either adnate to a fleshy fruiting perianth or free, endocarp crustaceous or woody, endosperm mostly present in small seeds, ab- sent in large seeds, embryo small with flat cotyledons in small seeds, large and with thick cotyledons in large seeds. Light-demanding plants of more or less open vegetations. The genera of the cecropiaceae Cecropia Loefling A of 70-80 genus probably species in tropical America, forming small to tall trees often with stilt-roots; stem and branches with hollow internodes; leaves lamina incised, with radial venation; inflorescences a large, peltate, radially pe- dunculate cluster of caducous of digitate spikes enveloped by a spathe; perianth staminate and flowers pistillate tubular; stamens 2; stigma capitate-penicillate or peltate, ovule basal; fruit a nutlet, endocarp crustaceous, tuberculate or smooth; endosperm present, cotyledons flat, radicle relatively long. Musanga R. Brown A 2 genus of species in tropical Africa forming trees with stilt-roots; stem and branches with hollow internodes; leaves large, lamina peltate, radially incised, with radial venation; staminate inflorescences repeatedly branched, bearing globose clusters of flowers on the ultimate dichotomies; perianth 2-lobed, inflorescence stamen 1; pistillate a clavate, more or less applanate spike; perianth tubular, stigma capitate-penicillate, ovule subbasal; fruit small, endocarp crustace- ous, tuberculate;endosperm present, cotelydons flat, radicle relatively long. Coussapoa Aublet A genus of more than 50 species in tropical America. Usually hemi-epiphytic shrubs or trees with aerial roots or with stilt-roots if terrestrial; leaves with an inflores- entire lamina, pinnately veined to subtriplinerved to palmately veined; cences cymosely branched with capitate clusters of flowers on the ultimate in dichotomies, pistillate inflorescences sometimes reduced to a single head; of the staminate flower with less perianth 3, more or connate tepals, stamens either free two, or entirely connate, or one; perianth of the pistillate flower fruit tubular, stigma capitate-penicillate, ovule basal; small, with a mucilaginous outside the layer verrucate crustaceous endocarp; endosperm scarce (or lacking?), cotyledons flat, radicle relatively long. Poikilospermum Zipp. ex Miquel A of 20 genus species in tropical Asia. Hemi-epiphytic scramblers with aerial lamina roots; entire, mostly pinnately veined, with punctiform or elongate cysto- liths; stipules not (fully) amplexicaul. Inflorescences cymosely once or repeated- with of ly branched, capitate clusters flowers on the ultimate dichotomies; of the perianth staminate flower with 4-2 free or basally connate tepals, stamens 4-2, straight or inflexed and straightening gradually at anthesis; perianth of the flower pistillate tubular, 4-lobed to 4-dentate, stigma ligulate to capitate-peltate, ovule basal; fruit small, with a mucilaginous layer outside the tuberculate crustaceous endocarp; endosperm scarce or lacking (?), cotyledons rather flat, radicle relatively long. 40 TAXON VOLUME 27 Myrianthus Palisot de Beauvois A of 7 genus species in tropical Africa. Usually medium-sized trees or shrubs with stilt-roots lianas. or sometimes Leaves with a simple, entire and pinnately veined or with a lobed and palmately veined lamina, or the lamina compound, with 3-7 leaflets; stipules sometimes not fully amplexicaul; staminate inflores- cences repeatedly branched, bearing sessile flowers closely set on the ultimate dichotomies or down to more proximal dichotomies; perianth with 4(-3), free or basally connate tepals, stamens 4(-3), free or connate; pistillate inflorescences capitate; perianth tubular, 2-3-lobed, stigmas lingulate, ovule basal; fruit large, adnate to the enlarged fleshy perianth, endocarp woody; endosperm lacking, cotyledons thick, radicle short. Pourouma Aubler A of genus probably more than 50 species in tropical America. Small or medium-sized trees, often with stilt-roots; lamina entire or palmately incised, venation pinnate to palmate; inflorescences repeatedly branched, the pistillate sometimes subumbellate; flowers often ones staminate pedicellate and mostly more or less densely glomerate onthe ends of the ultimatedichotomies; perianth 4(-3)-lobed to 4(-3)-parted, stamens 4(-3), straight; pistillate flowers usually entire pedicellate; perianth tubular, to 4(-3)-lobed or 4(-3)-dentate, stigma (sub)peltate, ovule subbasal to almost lateral; fruit large, free from the enlarged, less fleshy perianth, endocarp more or woody; seed large, endosperm lacking, cotyledons thick, radicle short. The of the 6 genera Cecropiaceae are two by two very similar in their ecolo- and of fruit Most and gy, habit, characters the and seed. species of Coussapoa the of Poikilospermum are hemi-epiphytes, species Cecropia and Musanga are and of mostly pioneer plants, most species Pourouma and Myrianthus are small or medium-sized trees of the lower stories of more or less open and disturbed forests. Poikilospermum has been revised by Chew Wee-Lek, Card. Bull. Singapore 20: 1-104. 1963; Musanga and Myrianthus have been revised by de Ruiter, Bull. Jard. Bot. Belg. 46: 471-510. 1976. KEY TO THE GENERA OF THE CECROPIACEAE 1. Leaves peltate, their incisions and venation radial. 2. Both staminate and pistillate flowers in spikes arranged in digitate clusters enveloped by a spathe. Cecropia 2'. Staminate flowers in capitules on the ultimate dichotomies of branched inflorescences, the pistillate flowers in a more or less applanate spike. Musanga 1'. Leaves entire to (sub)palmate. 3. Fruits large (more than 1 cm long); terrestrial trees or shrubs. 4. Pistillate flowers sessile in a capitate inflorescence; staminate flowers sessile. Myrianthus 4'. Pistillate flowers pedicellate in branched (or subumbellate) inflore-