118 



Ki;V TO THE FAMILIES AM) GENERA 



163. PLATANACE^E. 



Sole genus Ptatanus. 



168. LEITNERIACE^E. 

 The only genus . Leitneria. 



164. MORACE^E. 



A. Anthers reversed on the bud with inflexed 



filaments. 

 B. The male fls. spicate, racemose or capitate; 



female globose, capitate. 

 c. Female perianth dentate 1. Broussonc- 



cc. Female perianth deeply 4-fid 2. Madura. 



BB. The fls. of either sex spicate; spikes short 



and dense or long and lax 3. Morus. 



BUB. The fla. crowded on fleshy receptacle 4. Dorstenia. 



AA. Anthers erect from the beginning. 



B. Plants, trees or shrubs: fls. usually on a 

 9 fleshy receptacle. 



c. The receptacle fleshy, globose or ovoid, 

 clearly inclosing the numerous 6s., but 

 with a small mouth which is bracteate 



introrsely; the mouth is closed in fr 5. Ficus. 



cc. The receptacle androgynous, male fls. 

 numerous, females solitary in the 



center of the receptacle 6. Brosimum. 



ccc. The receptacle unisexual, with an invo- 

 lucre of numerous bracts overlapping in 



series 7. Antiaris. 



cccc. The fl.-clusters unisexual, with or without 

 3-4 bracts at the base, in heads, spikes, 

 rarely in racemes or the female 1-fld. 



D. Stamens 4 8. Cudrania. 



DD. Stamens 1 9. Artocarpus. 



BB. Plants, herbs: fls. not on a fleshy receptacle. 

 c. St. climbing: Ivs. opposite: embryo 



spirally involute 10. Humulus. 



cc. St. not climbing: Ivs. alternate or the 



lowest opposite: embryo curved 11. Cannabis. 



Coussapoa is also briefly treated. 



165. XTRTICACE^. 



A. Hairs stinging. 



B. Achene straight 1. Urtica. 



BB. Achene oblique 2. Urera. 



AA. Hairs harmless. 



B. Perianth of the female fl., 3-5-parted. 



c. Lvs. opposite: stamens 4, rarely 2-3 3. Pilea. 



cc. Lvs. alternate, distichous, oblique at 



base: stamens 5 t rarely 4 4. Pellionia. 



BB. Perianth of the female fl. tubular, inclosing 

 the achene, not adnate: Ivs. opposite or 



alternate: fls. in clusters or panicles 5. Boehmeria. 



BBB. Perianth of the female fl. tubular adnate to 

 the achene: Ivs. alternate, tomentose be- 

 low: fls. in globular heads often forming 

 cymes G. Debregeasia. 



Helxine, Parietaria, and Pipturus are described. 



166. ULMACE^E. 



A. Fr. drupaceous: fls. on the young growth. 

 B. Cotyledons very broad. 



c. Sepals connate; style excentric 1. Zelkova. 



cc. Sepals distinct or nearly so; style cen- 

 tral. 



D. Fr. globose, not winged 2. Celtis. 



DD. Fr. winged 3. Pteroceltis. 



BB. Cotyledons narrow. 



c. Fertile fls. perfect; fls. in cymes 4. Trema. 



cc. Fertile fls. unisexual, solitary, staminate 



in cymes before the Ivs 5. Aphananthe. 



AA. Fr. not drupaceous, winged or muricate: 

 fls. on last year's branches. 



B. Fr. stalked, surrounded by a broad wing 6. Ulmus. 



BB. Fr. not winged, everywhere somewhat 



fleshy and muricate 7. Planera. 



167. JUGLANDACE^E. 



A. The fls. of either sex in erect spikes, imbricate- 



bractate 1. Phiti/carya. 



AA. The staminate fls. in pendulous catkins; pis- 

 tillate fls. spicate or Bubsolitary. 

 B. In germinating, cotyledons are borne above 



ground and remain green 2. Pterocarya. 



BB. In germinating, cotyledons remain inside 



the nut. 

 c. Husk at length splitting into segms.; nut 



smooth or angled 3. Carya. 



cc. Husk indehiscent; nut wrinkled or 



sculptured 4. Juglans. 



169. MYRICACE.E. 



A. Lvs. serrate or entire, not stipulate: ovary 



subtended by 2-4 bractlets 1, Myrica. 



AA. Lvs. pinnatifid, stipulate: ovary subtended by 



8 linear, persistent bractlets 2. Comptonia. 



170. CASUARINACE^E. 



Sole genus Casuarina. 



171. EUPHORBIACE^E. 



A. Ovules 2 in each cell of ovary: plant without 



milky juice (or red juice in Bischofia). 

 B. Lvs. alternate, simple (sometimes opposite 



in Poranthera). 

 c. Calyx of staminate fls. imbricate. 



D. Petals present, at least in staminate 



fls. 



E. Plant a shrub with broad, glabrous 

 or somewhat hairy Ivs. : ovary 



3-celled . l. Andrachne. 



EE. Plant a tree, with scaly herbage: 



ovary 1-celled 2. Mxtoxicon. 



EEE. Plant a heath-like sub-shrub: Ivs. 



narrow, with recurved margin 3. Poranthera 



DD. Petals p. 



E. Fls. single or in axillary clusters. 

 F. Styles slender or only broadened 



at apex. 



o. Rudimentary pistil present in 

 staminate fls.; disk present: 

 Ivs. entire. 

 H. Seed grooved on inner face: 



disk of pistillate fl. lobed ... 4. Fluggm. 

 HH. Seed not grooved: disk en- 

 tire 5. Securinega, 



ao. Rudimentary pistil absent. 



H. Disk present 6. Phyttanthus. 



HH. Disk absent, at least from 

 pistillate fls. 



I. Fr. a caps 7, Glochidion, 



n. t r. more or less fleshy. 



j. The styles 2-parted 8. Breynia. 



jj. The styles almost entire. . 9. Sauropus. 

 FF. Styles broad, spreading. 



o. Stamens arising from a disk. 

 H. Staminate fls. with rudi- 

 mentary pistil 10. Drypetes. 



HH. Staminate fls. without rudi- 

 mentary pistil 11. Hemicyclia. 



GG. Stamens 2-4, without disk 12. Putranjiva. 



EE. Fls. in elongated catkin-like or 

 branched inn., dioecious: Ivs. large, 

 broad and plane. 



F. Ovary 1-celled; stamens 2-5 13. Antidesma, 



FF. Ovary 2-5-celled. 



a. Staminate fls. with rudimentary 



pistil 14. Baccaurea. 



GG. Staminate fls. without rudimen- 

 tary pistil 15. Daphniphyl- 



cc. Calyx of staminate fls. valvate; petals [/urn., 



small 16. Lebidierop- 



BB. Lvs. alternate, compound 17. Bischofia. 



BBB. Lvs. opposite, compound 18. Oldfieldia. 



BBBB. Lvs. whorled, simple. 19. Hyzenanche. 



AA. Ovules 1 in each cell of the ovary. 



B. Fls. produced singly or in ordinary infl. 

 c. Stamens incurved in the bud; pubescence 



stellate or scaly; juice not milky 20. Croton. 



cc. Stamens erect in the bud. 



D. Juice not milky (see also Codiseum and 

 relatives): calyx valvate: Ivs. simple. 



E. Staminate fls. with petals: herbs 21. Chrozophora. 



EE. Staminate fls. apetalous. 



F. Stamens much branched: herbs 

 with Ivs. palmatcly veined 



and peltate 22. Ricinut. 



FF. Stamens not branched. 



G. Lvs. opposite: styles free (see 



also Mallotus). 

 H. The stamens as many as 50. .23. Trewia. 



HH. The stamens 8-20 24. Mercurialis. 



G'i. Lvs. alternate, or rarely oppo- 

 site. 



H. Plant a thorny shrub: sta- 

 mens 8-15 25. Adelia. 



HH. Plant with holly-like spiny 



margined Ivs.: stamens 3-8. 26. Alchornea. 



