EUPHORBIACEAE 713 



32. Chamaesyce Tracy! Small. Annual, somewhat pubescent. Stems simple below 

 and erect, or branched at the base, the branches ascending. 1-5 dm. long, usually reddish, 

 thinly canescent : leaf-blades oblong or slightly broadest above the middle, mostly 5-13 

 mm. long, shallowly toothed near the apex, glabrous at maturity, short -petioled : involucres 

 campanulate, about 1 mm. high, not split : glands transversely oblong, about 0.4 mm. 

 broad ; appendages minute, undulate : capsules about as broad as long, barely 1.5 mm. 

 high, slightly pubescent all over, but especially so below the middle : seeds 4-angled, 

 oblong-ovoid, about 0.8 mm. long, some or all of the faces slightly wrinkled. 



In sandy soil, southern Mississippi. Summer. 



33. Cbamaesyce humistrata (Engelm. ) Small. Annual, light green, puberulent or 

 sparingly pilose. Stems branched from the base, the branches slender, radiately spreading, 

 prostrate or ascending, 1-3 dm. long : leaf-blades ovate-oblong or sometimes narrower, 4-10 

 mm. long, serrulate at least above the middle, oblique, obtuse or subcordate at the base, 

 short-petioled ; stipules at length fringed : involucres in lateral clusters, split on one side, 

 1 mm. long, faintly nerved : glands 4, disk-like ; appendages'narrow, irregular, red or white : 

 capsules depressed-globose, less than 2 mm. in diameter, its 3 lobes keeled : seeds oblong, 1 

 mm. long, papillose, ash-colored, obscurely transverse-wrinkled. [Euphorbia humistrata 

 Engelm.] 



In dry or sandy soil, Quebec to New York, Kansas and Mississippi. Summer and fall. 



34. Chamaesyce pergemena Small. Biennial or perennial, glaucescent. Stems 

 branched at the base, the branches slender, wire-like, 0.5-1.5 dm. long, glabrous or nearly 

 so, forking : leaf-blades parchment-like, oblong or ovate, very oblique, 3-6 mm. long, ob- 

 tuse, serrulate, minutely pubescent on both sides, conspicuously inequilateral, cordate or 

 subcordate at the base, short-petioled : involucres campanulate, 1.5 mm. high, minutely 

 pubescent, with a split on one side through which the pedicel protrudes : glands trans- 

 versely oblong, variable in size, about 0.5 mm. broad ; appendages white or pink, as long 

 as the glands or longer, one much longer than the others, more or less uneven along the 

 edges : capsules about 1 mm. high, minutely pubescent : seeds less than 1 mm. long, the faces 

 transversely wrinkled. [Euphorbia pergemena Small.] 



In sand, peninsular Florida. Also in the West Indies. Spring to winter. 



35. Chamaesyce prostrata (Ait.) Small. Annual, more or less pubescent or gla- 

 brate. Stems branched at the base, the branches prostrate, 0.5-2 dm. long, forking, com- 

 monly very leafy : leaf-blades oval, obovate or oblong, Often a little broadest above the 

 middle, 4-6 mm. long, obtuse, sparingly serrulate at the apex, oblique at the base, mani- 

 festly petioled : involucres turbinate, 0.5-0.7 mm. high : glands minute, 0.3 mm. broad ; 

 appendages narrow : capsules 1 mm. high, somewhat broader, pubescent along the angles : 

 seeds less than 1 mm. long, transversely wrinkled. [Euphorbia prostrata Ait.] 



In sandy soil, Florida to Texas and Mexico. 



36. Chamaesyce malaca Small. Annual, pubescent. Stems branched at the base, 

 the branches prostrate, closely and softly pubescent, especially when young, 2-5 dm. long, 

 forked : leaf-blades broadly oblong, 1-1.5 cm. long, or shorter on the branch! ets, obscurely 

 toothed above the middle, mostly blunt, oblique at the base and very inequilateral, with 

 slender but short petioles : involucres turbinate-campanulate, fully 1 mm. high, minutely 

 pubescent, longer than the peduncles : glands about 2 mm. broad ; appendages undulate, 

 minute, very variable in size: capsules ovoid-globose, about 1.5 mm. high, sparingly 

 pubescent : seeds oblong-ovoid, fully 1 mm. long, sharply angled, with strong transverse 

 wrinkles. 



On plains and prairies, the Indian Territory to Louisiana and Texas. Summer and fall. 



37. Chamaesyce maculata (L. ) Small. Annual, dark green, puberulent or pilose. 

 Stems branched at the base, the branches slender, radiately spreading, prostrate, 5-40 cm. 

 long, often dark red : leaf -blades usually blotched, oblong or ovate-oblong, 4-16 mm. long, 

 obtuse, more or less serrate, short-petioled, the base oblique, subcordate ; stipules a fringe 

 of bristles : involucres solitary in the axils, mostly 1 mm. long : glands 4, cup-shaped ; 

 appendages narrow, white or red, crenulate : peduncles shorter than the involucres : cap- 

 sules ovoid-globose, about 2 mm. in diameter, pubescent : seeds ovoid-oblong, less than 1 

 mm. long, obtusely angled, ash-colored, minutely pitted and inconspicuously transverse- 

 wrinkled. [Euphorbia maculata L.] 



Throughout North America, except the extreme north. Apparently introduced west of the Rocky 

 Mountains. Spring to fall. 



38. Chamaesyce conf&ta Small. Annual, more or less villous. Stems branched at 

 the base, the branches spreading and prostrate, 0.5-2 dm. long, often forked, short -jointed : 

 leaves approximate, clustered on short branchlets ; blades oblong to ovate, 3-6 mm. long, 

 acutish or obtuse, serrate, paler and more densely pubescent beneath than above, truncate 



