156 MANUAL OF POISONOUS PLANTS 



carpels united; in one division ovules with many megaspores. In most plants 

 of the other division there is a single megaspore with synergidal and antipodal 

 cells. (Choripetalae and Apetalae). a. Archichlamydeae. 395 



Tropical plants with monoecious flowers and branches with a longitudinal 

 ridge in which the stomata are hidden. Verticillatae. 395 



Dicotyledonous herbs ; petals and sepals absent ; flowers small spicate with 

 bractlets. Piperales. 396 



Trees or shrubs ; flowers small, in catkins, imperfect ; sepals and petals 

 none; leaves simple; fruit a many-seeded capsule; seeds with tufts of hairs 

 at one end. Salicales. 396 



Trees or shrubs ; leaves simple ; flowers small, monoecious or dioecious, in 

 catkins; perianth absent; ovary 1-celled: style short; stigmas 2; endosperm 

 none. Myricales. 397 



Woody plants with simple leaves ; flowers, staminate spicate, pistillate soli- 

 tary. Balanopsidales. 399 



Shrubs or trees ; flowers small, dioecious, in catkins ; leaves simple, alter- 

 nate, petioled, perianth absent in staminate flowers ; pistillate, subtended by 

 bractlets; ovary 1-celled; endosperm thin. Leitneriales. 400 



Trees with alternate, pinnately-compound leaves ; flowers monoecious, with 

 bractlets, staminate in catkins, pistillate, solitary or several ; ovule solitary, 

 erect; fruit a drupe, indehiscent or dehiscent, with woody husk, seed large 

 2-4 lobed ; endosperm none. Juglandales. 400 



Trees or shrubs; flowers small; calyx usually present; monoecious, or 

 rarely dioecious, in catkins ; pistillate flowers subtended by an involucre which 

 becomes a bur or cup in fruit. Fagalcs. 402 



Shrubs, herbs or trees ; calyx present but corolla absent ; flowers small, not 

 borne in catkins, monoecious, dioecious or polygamous; ovary 1-celled superior. 



Urticales. 404 



Shrubs, trees or herbs with scattered leaves ; flowers in spikes, racemes 

 or panicles usually perfect; single carpel. Proteales. 415 



Herbs or shrubs; generally parasitic; calyx present; corolla absent; flowers 

 perfect, or imperfect; a single inferior ovary; fruit various. Santalales. 415 



Generally vines or herbs; leaves cordate, or reniform; corolla absent; calyx 

 inferior; tube wholly, or partly adnate to ovary: flowers perfect. 



Aristolochiales. 416 



Generally herbs, occasionally trees, shrubs or twining vines ; leaves simple, 

 mostly entire ; flowers small, regular, perfect, dioecious, monoecious or poly- 

 gamous; petals absent; stamens 2-9; filaments filiform or subulate; ovary 

 superior onc-cellcd ; ovule solitary; fruit an achene; endosperm mealy. 



Polygonalcs. 417 



Generally herbs, occasionally shrubs; flowers perfect; corolla usually ab- 

 sent, when present polypetalous ; calyx present; ovary superior; embryo coiled 

 curved or annular; albumen present. Centrospermae. 423 



Herbs, shrubs or trees; calyx usually of separate sepals; corolla generally 

 present, polypetalous; ovary superior; carpels many usually separate; stamens 

 generally free and more numerous than sepals. Raiiales. 444 



