464 



EUPHORBIACEAE. 



Vol. II. 



3. Chamaesyce serpens (II.H.K. 



Small. Round-leaved Spreading Sinirge. 

 "ig- 2734- 



Euphorbia serpens H.B.K. Nov. Gen. 2: 52. 1817. 

 Chamaesyce serpens Small, Fl. SE. U. S. 709. 1903. 



Annual, pale green, glabrous, sometimes glau- 

 cesccnt. Stem branched from the base, the slen- 

 der or filiform branches prostrate, 2'-l2' long; 

 leaves orbicular, orbicular-ovate or oval, i"-3" 

 long, obtuse or emarginate, entire, often slightly 

 re volute-margined, short-petioled,- the base ob- 

 lique, rounded or subcordate ; stipules triangular, 

 somewhat incised at the apex ; peduncles slightly 

 longer than the petioles ; involucres solitary in 

 the axils, nearly i" high, bearing 4 sessile saucer- 

 shaped glands shorter than the lobes, each sub- 

 tended by a minute irregular crenulate append- 

 age; capsule nodding, depressed-globose, i" in 

 diameter; seeds oblong-ovoid, i" long, smooth, 

 obtusely 4-angled, light gray. 



Illinois to Iowa, western Ontario, South Dakota 

 and Kansas, south to Mexico. West Indies. In bal- 

 last about the eastern seaports. March-Oct. 



4. Chamaesyce petaloidea (Engelm.) 



Small. White-flowered Spurge. 



Fig. 2735. 



Euphorbia petaloidea Engelm. Bot. Me.x. Bound. 



Surv. 185. 1859. 

 C, petaloidea Small, Fl. SE. U. S. 711. 1903. 



Annual, pale green, glabrous. Stem usually 

 rather stout, erect, branched above, 6'-2 high; 

 leaves opposite, linear, oblong or linear-lanceo- 

 late, 5"-i' long, obtuse, usually flat, straight, 

 entire, slender-petioled ; stipules a fringe of setae; 

 involucres solitary in the axils, oblong-campanu- 

 late, i" long, bearing 4 wineglass-shaped glands 

 about as long as the lobes, each subtended by a 

 white ovate or orbicular entire or undulate ap- 

 pendage; peduncles as long as the involucres; 

 capsule globose-reniform, i" long; seeds oblong- 

 ovoid, nearly i" long, ash-colored, minutely 

 pitted, nearly terete. 



Prairies. Iowa to Wyoming, Missouri, Te.xas and 

 Arizona. luly-Sept. 



5. Chamaesyce zygophylloides (Boiss.) 

 Small. I'rairie Spurge. Fig. 2736. 



Euphorbia petaloidea var. Nuttallii Engelm. Bot. Mex. 



Bound. Surv. 1S5. 1S59. 

 E. ::ygophylloides Boiss. Cent. Euph. 10. i860. 

 , Euphorbia arenaria Engelm. & Gray, Bost. Journ. Nat. 



Hist. 5:260. 1847. Not Nutt. 1837. 



Annual, bright green, glabrous. Stem slender, erect 

 or ascending, branched, 4'-2 high, the branches 

 wiry, leaves mostly linear and mucronulate or trun- 

 cate at the apex, often involute, obtuse or narrowed 

 at the base, petioled, usually curved, the midvein 

 prominent; stipules lanceolate or subulate-lanceo- 

 late ; involucres solitary in the axils, campanulate, 

 less than l" long, long-peduncled, bearing 4 saucer- 

 shaped glands subtended by white entire oblong or 

 ovate appendages ; seeds ovoid, i" long, gray, 

 4-angled. 



Prairies, Missouri and Kansas to Texas and Mexico. 

 lune-Sept. 



