988 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



99. HELENIUM. Sneezeweed 



Biennial or perennial herbs; leaves alternate, usually narrow, entire 

 or toothed ; heads small to large, radiate or discoid, the rays yellow, the 

 disk yellow or purple brown; involucre about 2-seriate, spreading, at 

 length reflexed; achenes turbinate, 8- to 10-ribbed; pappus of 5 to 8 

 scarious paleae or squamellae. 



Key to the species 



1. Leaves not decurrent; plant subtomentose when young; rays spreading, linear 

 or oval. Leaves thickish, strictly entire, the lowest obovate or oblanceo- 

 late, normally 15 cm. long or longer; heads few (usually 3 to 6), large, at 



least 5 cm. wide across the spreading rays 1. H. hoopesii. 



1. Leaves more or less decurrent; plant not subtomentose; rays soon drooping, 

 cuneate, wanting in one species (2) . 

 2. Rays wanting; squamellae of the pappus very short and blunt. 



2. H. THURBERI. 



2. Rays present; squamellae of the pappus at least half as long as the corolla, 

 acute or acuminate (3) . 



3. Leaves laciniate; plant cinereous-puberulent 3. H. laciniatum. 



3. Leaves entire or slightly toothed; plants glabrous or puberulous, not 

 cinereous (4). 

 4. Leaves essentially uniform, sessile, lanceolate; stem winged essentially 



throughout; plant perennial 4. H. autumnale. 



4. Leaves not uniform, the basal ones oblanceolate, distinctly larger than 

 the cauline leaves and narrowed into a petioliform base; cauline 

 leaves with an ampliate amplexicaul base, very shortly decurrent; 

 stem not winged throughout; plant apparently biennial. 



5. H. ARIZONICUM 



1. Helenium hoopesii A. Gray, Acad. Nat. Sci. Phila. Proc. 1863: 



65. 1863. 



Dugaldia hoopesii Rydb., N. Y. Bot. Gard. Mem. 1: 425. 1900. 



Apache, Coconino, Greenlee, Graham, Cochise, and Pima Counties, 

 7,500 to 11,000 feet, abundant in rich soil in coniferous forests and 

 mountain meadows, June to September. Wyoming to Oregon, south 

 to New Mexico, Arizona, and California. 



Orange sneezeweed, sometimes called owlclaws. The plant contains 

 a toxic glucoside, dugaldin, which causes "spewing sickness" in sheep. 

 It is also poisonous to cattle, but is rarely eaten by them. 



2. Helenium thurberi A. Gray, Amer. Acad. Arts and Sci. Proc. 19: 



32. 1882. 

 Pinal, Cochise, and Pima Counties, 1,200 to 5,000 feet, marshy 

 places along streams, March to August, types from southern Arizona 

 (Coulter 359, Thurber 346, Pringle 137). Southern Arizona and 

 Mexico. 



*3. Helenium laciniatum A. Gray, Amer. Acad. Arts and Sci. Proc. 

 9:203. 1874. 

 Southeastern California, adjacent Arizona, and adjacent Mexico 

 (according to Gray 4 ). Gray's record of this plant from Arizona 

 appears to be based on the supposition that the original specimens of 

 Thomas Coulter (nos. 356, 358) may have come from that State. 

 There seems to be no definite record of the species from either Arizona 

 or California, and it is omitted from recent floras of California. 



4 Gray, A. synoptical flora of north America. P: 1884. (Seep. 349.) 



