542 



EUPHORBIACEAE 



inate flowers uppermost. Sepals 4-6, usually 5. Petals usually present, but 

 often small, alternating with the glands. Stamens 5 or more, inflexed in bud. 

 Pistillate flowers below the staminate ones. Sepals 5-10. Petals usually want- 

 ing. Ovary 3-celled; ovules sohtary in each cell; stigmas once, twice, or thrice 2- 

 cleft. Capsule mostly splitting into three 2-valved carpels. Seeds smooth or 

 minutely pitted. 



Annual; leaf-blades Linear, lanceolate, or oblong, 3-5 times as long as the petioles. 



1. C. texensis. 

 Perennial; leaf-blades elliptic or oval, only a Little longer than the petioles. 



2. C. longipes. 



1. C. texensis (Klotzsch) Muell. Arg. Lepidote, dioecious annual; stem 

 4-16 dm. high, di- or trirchotomously branched; the staminate plant usually 

 more slender than the pistillate one and with narrower leaves; leaf-blades linear, 

 lanceolate, or oblong, 4-12 cm. long, entire; staminate racemes 1-3 cm. long; 

 sepals oblong to ovate-oblong; stamens 8-12; pistillate flowers 2-4 together or 

 solitary; sepals triangular; capsule globose or oval, 4-6 mm. long, warty. Plains 

 and prairies: 111. — Ala.- — Tex. — Ariz. — Wyo.; Mex. Plain. My-Au. 



2. C. longipes M. E. Jones. Perennial, woody at the base, 3-6 dm. high, 

 white, lepidote-stellate; leaf -blades 2-3 cm. long, densely stellate beneath, 

 sparingly so or glabrate above; staminate flowers 2 mm. wide; pistillate ones 6 

 mm. wide; sepals in both triangular; capsule globose, densely stellate. Sand: 

 Utah — Nev. Son. — Submont. Ap-My. 



2. DITAXIS Vahl. 



Monoecious or rarely dioecious herbs or shrubs, often with rootstocks. 

 Leaves alternate, silky or pilose, entire or rarely toothed, often strongly veined. 

 Flowers in axillary and terminal clusters, usually bracted. Staminate flowers 

 usually crowded at the ends of the racemes. Sepals 4 or 5, valvate. Petals 4 or 

 5. Stamens of the same number, or twice or thrice as many; filaments united 

 into a column. Pistillate flowers with imbricate sepals and rudimentary petals. 

 Ovary 3-celled, each cell with a solitary ovule. Styles 3, 2-cleft. Capsule 

 3-lobed, depressed, separating into three 2-valved carpels. Seeds subglobose, 

 wrinkled or crested. 



1. D. humilis (Engelm. & Gray) Pax. Perennial, with a woody root and 

 caudex; stems much branched, pubescent, spreading, 1-3 dm. long; leaf -blades 

 ovate, oblong, or oblanceolate, 1-3 cm. long, entire; capsule short-pedicelled, 

 depressed, 4-6 mm. in diameter; seeds oval-globose, 2 mm. long, muricate. 

 Prairies: Kans. — La.^ — Tex. — N.M. Son. My-0. 



3. TRAGIA (Plum.) L. 



Perennial monoecious herbs, or shrubs, usually armed with stiff, stinging 

 hairs. Leaves alternate, entire, toothed, or lobed, mostly cordate, petioled. 

 Flowers in racemes or spicate racemes, bracteolate, apetalous. Staminate flow- 

 ers with 3-5 sepals, and mostly 1-3 stamens. Pistillate flowers with 3-8 sepals. 

 Ovary 3-celled; ovules solitary. Styles 3, often united to above the middle. 

 Capsule 3-lobed, separating into three 2-valved carpels. Seeds subglobose. 



1. T. ramosa Torr. Light green perennial, with a woody caudex, hispid; 

 stem 0.5-3 dm. high, usually much branched; leaf -blades lanceolate to triangular- 

 lanceolate, 1-5 cm. long, coarsely and sharply serrate; staminate flowers with 

 4-5 sepals and 5-6 stamens; pistillate flowers solitary, with 5 sepals subtended 

 by a 3-lobed bract; capsule depressed, 6-8 mm. thick, orange, more or less varie- 

 gated. Dry soil: Mo. — Tex. — Ariz. — Colo. Son. — Submont. Ap-Au. 



4. CHAMAESYCE S. F. Gray. Spurge, Carpet-weed. 



Annual or perennial herbs, or in the tropics shrubs. Stems often radially 

 branched at the base, ascending or prostrate, forking. Leaves opposite, entire 

 or toothed, more or less oblique at the base; stipules delicate, entire or fringed. 

 Involucres sohtary in the axils or in axillary cymes. Glands 4, sessile or stalked, 



