SENECIO COMPOSITE 375 



ked at base: the scales thin-herbaceous, lanceolate or linear, 

 equal, in one or two series. Receptacle flat, naked. Rays elon- 

 gated : disk-corollas with distinct and usually elongated tube and 

 funnelform or cylindraceous 5-lobed limb. Style-appendnges 

 obtuse, pubescent. Achenes linear, 5-anglcd or 5-10-ribbed, 

 somewhat hirsute or nearly glabrous. Pappus a single series of 

 rather rigid strongly scabrous or barbellate capillary bristles. 



1 Ours perennials with tomentose and usually floccose pu- 

 bescence or none, never viscid nor obviously hirsute. 



* Heads more than half-inch high, very many-flowered: disk 

 corollas merely 5-toothed : heads radiate. 



S. megacephalus Nutt. Trans. Am. Phil. Soc. vii, 410. About a foot 

 high, loosely floecpse-woolly, tardi'y glabrate, leafy: leaves entire, lanceo- 

 late and tapering into a petiole, uppermost cauline attenuate, thickish : 

 heads 1-3, short-peduncled, 8-12 lines high: involucre calyculate by some 

 very loose and setaceous-subulate elongated accessory bracts: rays over 

 half inch long. Mountains of Idaho. 



* * Heads middle-sized or small, erect, mostly radiate. 



*- Stems herbaceous, numerously and equally leafy to the top: 

 leaves pinnately veined, not conspicuously reticulate, from entire to 

 laciniate-dentate or dissected, not narrowly linear, glabrous or very 

 early glabrate and smooth. 



** Low, alpine : heads few or solitary. 



S. hesperis Greene. Pitt, ii, 166. Stems 4-10 inches high from short, 

 spreading rootstocks, leafy only at the decumbent base ; sparingly floccose- 

 tomentose when young, in age nearly glabrous : leaves thickish and some- 

 what fleshy, from round-oval to oblong and oblong-lanceolate, 6-12 lines 

 long, tapering or abruptly contracted to a short or long petiole, almost en- 

 tire or repandly or crenately few-toothed: head solitary half-inch high, 

 with the expanded rays 1 inch broad: involucre campanulate, the bracts 

 linear, outer calyculate ones few or none: rays 10-12 deep yellow, style tips 

 slightly penicillate. On the serpentine formation of the Coast range of 

 southern Oregon. 



S. Fremontii T. & G. Fl. ii, 445. Many-stemmed from a thickish cau- 

 dex, 6-12 inches high, leafy to the top: leaves thickish, from rounded-ob- 

 oyate or spatulate to oblong, obtuse, obtusely or acutely dentate, some- 

 times even pinnatifid-dentate ; lower abruptly contracted into a winged 

 petiole ; uppermost sessile by a broadish base : head half-inch high, short- 

 peduncled, subtended by a few short loose bractlets : rays 3-5 lines long. 

 Alpine regions of the Rocky Mountains to Lassen Peak California and 

 the Blue Mountains of Oregon. 



S. occidentalis Greene Pitt, iv, 122. S. Fremontii Var occidentalis 

 Gray. Stems many from running rootstocks, 4-12 inches high, rather 

 slender: leaves from round-obovate to spatulate, 6-12 lines long those in 

 the middle of the stem largest and the lowest smallest, coarsely dentate: 

 heads 1-several, about 6 lines high: bracts of the involucre linear, 1- 

 nerved, scarious -margined, the small accessary ones setaceous to lanceo- 

 late, rays 4-6 lines long. On the higher mountains, Oregon to California 

 and the Rocky mountains. 



S. streptanthifolius Greene Eryth. iii, 23. "Only a foot high, or even 

 less, from clustered leafy perennial rootstocks, glabrous throughout, some- 

 what fleshy-coriaceous and glaucous : leaves 1 to \% inches long, orbicular 



