EUPHORBIACEAE. 179 



sepals and numerous stamens. Pistillate flowers with caducous sepals and a 

 3-celled ovary. Fruit a capsule. 



1. R. commimis L. Plants herbaceous or shrubby, 1-5 m. tall, or larger south- 

 ward: leaf-blades nearly orbicular, 6-11-lobed: capsules 12-16 mm. in diameter, 

 echinate. — M. Occasional, in waste places and about gardens. Nat. of the 

 tropics. — Sum. — Castor-bean. Castor-oil plant. 



4. CHAMAESYCE S. F. Gray. Annual or perennial herbs, or shrubs. 

 Leaves opposite: blades oblique at the base. Involucres axillary or in axillary 

 cluster-like cymes, each with 4 nearly naked or appendaged glands, one sinus 

 being glandless. Capsules smooth, sometimes pubescent. Seeds smooth or 

 transverse-wrinkled. — Sum. — Spurge. 



Plants branched at the base, the branches prostrate : capsules less than 2 mm. 

 wide : involucre-appendages minute. 

 Capsules pubescent : involucre not split : stem and branches with appressed hairs. 



1. C. macnhita. 

 Capsules glabrous : involucre split on one side : stem and 

 branches with spreading hairs. 2. C. Rafinctiquci. 



Plants not branched at the base, erect or ascending : capsules 



over 2 mm. wide : involucre-appendages relatively large. 3. C. Preslii. 



1. C. maculata (L.) Small. Stem and branches puberulent or pilose: leaf- 

 blades oblong or ovate-oblong, 8-12 mm. long: involucres mostly 1 mm. long, 

 pubescent; appendages white or red, narrow, nearly equal, entire: capsules 

 less than 1.5 mm. wide, pubescent: seeds nearly 1 mm. long, black beneath the 

 pale coating. — Common, in cultivated and waste grounds. — Milk-purslane. 



2. C. Rafinesquei (Greene) Small. Stem and branches hirsute: leaf -blades 

 oblong, oblong-ovate, or ovate, 4-14 cm. long, obtuse or acute, light-green 

 above, pale-green and with scattered hairs beneath, serrate, short -petioled: 

 involucres about 1 mm. long, glabrous; appendages obscure or very narrow and 

 pale: capsules globose-ovoid, less than 2 mm. wide, glabrous: seeds less than 

 1.5 mm. long, red beneath the gray coating. — Local, on dry banks on and near 

 the Welch mountains. — Quartzite. 



3. C. Preslii (Guss.) Arthur. Stem and branches glabrous or nearly so: leaf- 

 blades oblong or linear-oblong, varying to ovate or obovate, 1.5-3.5 cm. long, 

 usually red-margined: involucres in loosely clustered cymules; appendages 

 usually white, entire : capsules fully 2 mm. wide. — Common, in fields and 

 waste places. 



5. TITHYMALOPSIS Kl. & Garcke. Perennial herbs often topped by an 

 umbel. Leaf-blades entire. Involucres scattered or somewhat clustered in an 

 umbel-like inflorescence, each with appendaged glands. Capsule smooth. Seeds 

 punctate. 



1. T. coroUata (L.) Small. Plants bright-green, 2-9 dm. tall: leaf -blades 

 linear, oblong, or oblong-spatulate, 2-4 cm. long: involucres numerous, con- 

 spicuous, 1-1.5 mm. long: appendages white, mostly cuneate or orbicular- 

 cuneate: capsules exserted, 3.5-4.5 mm. broad: seeds 2.5 mm. long. — Common, 

 in fields and thickets, and on roadsides. — Sum. — Flowering-spurge. 



6. TITHYMALUS Adans. Annual or perennial herbs or partially woody 

 plants topped by an umbel. Leaf-blades entire or finely toothed. Stipules 

 wanting. Involucres in open or compact cymes, each with 4 naked or ap- 

 pendaged glands. Capsule smooth or tuberculate. Seeds pitted. — Sum. — 

 Spurge. 



