VOI,. II.] 



SPURGE FAMILY. 



i. Euphorbia polygonifolia L/. Seaside or Knotweed Spurge. 



Euphorbia polygonifolia L. Sp. PI. 455- 1753- 



Annual, pale green, glabrous, stem branched 

 from the base, the branches radiately spreading, 

 prostrate, forked, wiry, s'-S' long. Leaves op- 

 posite, oblong, linear-oblong or linear-lanceo- 

 late, 3 // -io // long, fleshy, obtuse, often mucronu- 

 late, entire, obtuse or subcordate and somewhat 

 oblique at the base, short-petioled; stipules an 

 inconspicuous fringe of short bristles; invo- 

 lucres usually solitary in the axils, turbinate- 

 campanulate, less than i" long, with 4 colum- 

 nar nearly naked glands shorter than the lobes; 

 peduncles twice as long as the involucres; cap- 

 sule globose-ovoid, i^ // -2 // long, nodding, 

 minutely wrinkled; seeds ovoid, i%" long, 

 somewhat flattened, ash-colored, very minutely 

 pitted and spotted. 



In sand along the Atlantic coast, Rhode Island to 

 Florida, and on the shores of the Great Lakes. 

 July-Sept. 



371 



(Fig. 2307.) 



2. Euphorbia petaloidea Engelm. 

 White- flowered Spurge. (Fig. 2308.) 



Euphorbia petaloidea Engelm. Bot. Mex. Bound. 

 Surv. 185. 1859. 



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- 

 campanulate, \f long, bearing 4 wineglass- 

 shaped glands about as long as the lobes, each 

 subtended by a white ovate or orbicular entire 

 or undulate appendage; peduncles as long as the 

 involucres; capsule globose-reniform, l" long, 

 seeds oblong-ovoid, nearly i" long, ash-colored, 

 minutely pitted, nearly terete. 



Iowa to Wyoming and Texas. July-Sept. 



3. Euphorbia Nuttallii (Engelm.) Small. 

 Prairie Spurge. (Fig. 2309.) 



Euphorbia petaloidea var. Nuttallii Engelm. Bot. 



Mex. Bound. Surv. 185. 1859. 

 E. zygophylloides Boiss. Cent. Euph. 10. 1860. 

 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 mu- 

 cronulate or truncate at the apex, often involute, 

 obtuse or narrowed at the base, petioled, usually 

 curved, the midvein prominent; stipules lanceo- 

 late or subulate-lanceolate; involucres solitary in 

 the axils, campanulate, less than i" long, long- 

 peduncled, bearing 4 saucer-shaped glands sub- 

 tended by white entire oblong or ovate append- 

 ages; seeds ovoid, |^ // long, gray, 4-angled. 



Prairies, Kansas to Texas and Mexico. June-Sept. 



