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. J'erticillatae. 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. Fagales. 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 one-celled; ovule solitary; fruit an achene; endosperm mealy. 



Polygonales. 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. Ranales. 444 



