1907] Hall. Compositae of Southern California. . 205 



leaves sessile, elongate-oval, acute, entire, about 3 cm. long : heads 

 on slender peduncles, hemispheric, about 2 cm. broad excluding 

 rays, very woolly at base: inner bracts with long-pointed tips: 

 receptacle high-conic, obtuse: achenes pubescent: pappus-paleae 

 white, nearly three-quarters as long as disk-corolla, long-pointed, 

 the tip sometimes bifid. 



Known only from a scrap in the herbarium of Dr. E. L. 

 Greene, labeled as coming from Southern California and com- 

 municated by Prof. Wickson ; but possibly not Calif ornian. 



H. RICHARDSONII (Hook.) Ckll., in some of its forms, is to be 

 looked for along our northeastern borders. Stems usually low 

 (2 dm. or less), from large perennial roots: leaves pinnatifid, the 

 radical with wool in their axils : pappus-paleae long-acuminate or 

 aristate. 



H. FLORIBUNDA uTiLis Ckll. is the Colorado Rubber Plant, at 

 home in the mountains of Colorado and New Mexico. All parts 

 of the plant, but especially the thick yellow roots and stems, yield 

 a caoutchouc-like substance. 



77. HELENIUM L. SNEEZEWEED. 



Erect herbs, ours perennial and with resinous-dotted foliage. 

 Leaves alternate, sessile except the lower, often decurrent on the 

 stem. Heads solitary or cymose, borne on long naked peduncles. 

 Flowers yellow, or the lobes of the disk-corolla turning yellowish 

 or brownish, either all perfect or the ray-flowers pistillate or 

 neutral. Rays several, usually drooping. Bracts of the involucre 

 linear, reflexed. Receptacle globose or hemispheric, naked. 

 Achenes turbinate, ribbed. Pappus of 5 to 12 thin or hyaline 

 paleae, in ours short-pointed. 



Kays shorter than the disk, 2 to 8 mm. long 1. E. puberulum. 



Kays equalling or longer than the disk, 10 to 20 mm. long 2. H. Bigelovii. 



1. H. puberulum DC., Prodr. v. 667 (1836). Heleniastrum 

 puberulum Ktze., Rev. Gen. i. 342 (1891). ROSILLA. 



Paniculately branched, 6 to 15 dm. high, the branches ending 

 in long slender peduncles : herbage puberulent : basal leaves ob- 

 lanceolate, usually sinuate-margined ; cauline leaves lanceolate, 

 oblong, or the upper ones linear, entire, sessile and strongly de- 



