76 EUPHORBIACEAE. 



Stamens 10 or fewer : petals present. 15. Jatropha. 



Flowers in simple or branched racemes. 16. Manihot. 



Flowers in involucres : calyx represented by a scale. 



Involucre regular or nearly so, nearly or quite equilateral. 

 Glands of the involucres with petal-like appendages, 



these sometimes much reduced. 17. Chamaestce. 



Glands of the involucres without petal-like appendages, 

 entirely naked, sometimes with crescent-like horns. 

 Stem topped by an umbel : stipules none : involucres 

 in open cymes, each with 4 glands and entire or 

 toothed lobes. 18. Tithtmalus. 



Stem not topped by an umbel : stipules gland-like : 

 involucres in cluster-like cymes, each with a 

 single gland or rarely 4 glands and fimbriate lobes. 19. Poinsettia. 

 Involucre irregular, very oblique. 20. Pedilaxthus. 



1. SAVIA Willd. Shrubs or trees. Leaves alternate : blades thick, entire. 

 Flowers dioecious ; the staminate densely clustered, with 5 broad rounded sepals 

 and 5 thin petals broadened upward: stamens 5, exserted. Pistillate flowers 

 solitary or few together, with 5 broad sepals and 5 nearly similar petals: ovary 

 3-lobed; styles 2-parted. Capsule depressed. 



1. S. bahamensis Britton. Small tree or shrub, the bark pale gray or whitish: 

 leaf-blades typically obovate, varying to narrowly obovate or oval-obovate, 2-5 

 cm. long, rounded at the apex, or rarely retuse or acutish, pale-green, shining 

 above, glabrous, short-petioled: staminate flowers with orbieular-ovate sepals 

 about 2 mm. long and euneate or flabellate thin petals shorter than the sepals: 

 pistillate flowers with suborbieular sepals and petals about 2 mm. long: capsules 

 spheroidal, 5-6 mm. long: seeds 4-5 mm. long. — Hammocks and j)almlands, 

 L. keys. — {Bah., Cuha.) 



2. XYLOPHYLLA L. Shrubs or small trees, with flattened leaf-like, 

 usually distichous, branchlets. Leaves minute or obsolete. Flowers borne in 

 clusters along the margins of the leaf -like branchlets. Staminate flowers mostly 

 with 6 sepals and 3 stamens. Pistillate flowers mostly with 6 sepals and a 

 3-celled ovary. Fruit capsular. 



1. X. Epiphyllanthus (L.) Britton. Shrub 1-2 m. tall: flattened branchlets 

 almost linear varying to somewhat spatulate or lanceolate, commonly 4-10 cm. 

 long: larger sepals of the staininate flowers 1-1.5 mm. long: capsules 4-5 mm. 

 broad. — Hammocks, Key West. — (Bah., Cuba, Ant.) — Not recently collected. 



3. PHYLLANTHUS L. Herbs or partially woody plants. Leaf-blades 

 entire. Flowers apetalous. Staminate flowers with 5 or 6 sepals and usually 3 

 stamens. Pistillate flowers with 5 or 6 sepals and a 3-celled ovary. Fruit 

 capsular. 



Plants annual : mature pistillate calyx 2.5 mm. wide. 



Leaf-blades euneate to obovate : capsules about 1.5 mm. wide. 

 Leaf-blades oblong or nearly so : capsules about 2 mm. wide. 

 Plants perennial : mature pistillate calyx 3 mm. wide. 



Leaf-blades oblong or nearly so : staminate calyx 2 mm. wide ; 



sepals ovate to orbicular-ovate. 

 Leaf-blades euneate : staminate calyx 1.5 mm. wide ; sepals 

 suborbieular. 



' 1. P. saxicola Small. Plants 0.5-3.5 dm. tall: leaf-blades euneate to obovate, 

 abruptly narrowed at the base: staminate calyx 1.5 mm. wide; sepals subor- 

 bieular: mature pistillate calyx 2.5 mm. wide; sepals ovate to oblong-ovate: 

 capsules about 1.5 mm. wide. — Low pinelands and hammocks, L. keys. — [E. K.] 

 — {Bah.) 



2. P. Niruri L. Plants 1-3 dm. tall: leaf -blades thin, oblong or nearly so: 

 staminate calyx 1.5 mm. wide; sepals orbicular-ovate: mature pistillate calyx 



