468 



EUPHORBIACEAE. 



Vol. II. 



15. Chamaesyce Preslii (Guss.J Arthur. Large or Upright Spotted Spurge. 



Fig. 2746. 



Euphorbia Preslii Guss. Fl. Sic. Prodr. i ; 539. 1827. 

 Euphorbia hypericifolia A. Gray, Man. 407. 1848. Not 



L- 1753- 

 Chamaesyce Preslii Arthur, Torreya 11 : 260. 1912. 



Annual, glabrous or sparingly pubescent. Stem 

 branched, at least above, ascending or erect, y'-2'' 

 high, the branches mostly spreading, often recurved 

 at the ends; leaves opposite, oblong, or linear-oblong, 

 varying to ovate or obovate, often falcate, oblique, 

 3-nerved, unequally serrate, often with a red blotch 

 and red margins, short-petioled ; stipules triangular, 

 slightly lacerate; involucres narrowly obovoid, i." 

 long, one-half or one-third as long as the peduncles, 

 bearing 4 glands subtended by orbicular or reniform 

 entire white or red appendages; capsule glabrous, 1" 

 in diameter; seeds oblong-ovoid, i" long, 4-angled, 

 with broken transverse ridges. 



In fields and thickets, Ontario to Massachusetts, Flor- 

 ida, Wisconsin, Nebraska and Texas. Has been con- 

 fused with C.nntans (Lag.) Small, of Mexico. May-Oct. 



13. ZYGOPHYLLIDIUM Small, Fl. SE. U. S. 714. 1903. 



Annual herbs, with erect forking stems. Leaves opposite, rarely alternate on the lower 

 part of the stem, narrow, equilateral, not oblique at the base, entire; stipules gland-like, often 

 obsolete. Involucres delicate, short-peduncled in the upper forks. Glands S, broader than 

 long, subtended by petal-like appendages. Capsules long-pedicelled, 3-lobed. Seeds terete, 

 usually narrowed upward, more or less papillose, the caruncle sometimes wanting. [Greek, 

 resembling Zygophyllum.] 



About 5 species, natives of North America. Type species : Zygophyllidium hexagonum 

 (Nutt.) Small. 



I. Zygophyllidium hexagonum (Nutt.) 

 Small. Angled Spurge. Fig. 2747. 



Euphorbia hexagona Nutt.; Spreng. Syst. 3: 791. 



1826. 

 Zygophyllidium hexagonum Small, Fl. SE. U. S. 714. 



1903. 



Annual, yellowish green, glabrous or sparingly 

 pubescent. Stem slender, striale-angled, erect, or 

 assurgent, 4-20' tall, branched, the branches as- 

 cending, often almost filiform ; leaves opposite, 

 linear, oblong or lanceolate, very short-petioled, 

 obtuse or acute, equilateral ; stipules obsolete or 

 very narrow ; involucres solitary in the axils, often 

 clustered, i"-t1" long, ciliate, pubescent, short- 

 peduncled, with 5 glands subtended by triangular- 

 ovate whitish or green appendages ; capsule gla- 

 brous, 2" in diameter; seeds ovoid or oblong- 

 ovoid, jI" long, terete, papillose. 



Iowa to Montana, Texas and Colorado. Also at 

 Wilmington, Del. June-Oct. 



14. DICHROPHYLLUM Kl. & Garcke, Monatsb. Akad. Ber. 1859: 249. 



Annual caulescent herbs, with the erect stems often topped by a several-rayed umbel. 

 Leaves scattered below the umbel, above it opposite or whorled, often petal-like and very 

 showy, entire; stipules at the base of the petioles or leaf-blades, fugacious. Involucres cam- 

 panulate, in rather dense cymes, pubescent without and within; lobes fimbriate. Glands 5, 

 peltate, somewhat concave, with white or pink petal-like appendages. Capsule exserted. large, 

 pubescent, the lobes rounded. Seeds narrowed upward, reticulated, with caruncles. [Greek, 

 referring to the colored leaves or bracts.] 



About 4 species, natives of North America, the following typical. 



