556 COMPOSITE. 



foot or so woody at base), ending in a, corymbose panicle of several 

 heads or the simple sterile shoots densely leafy at summit; leaves 

 thick, oblong or cuneate-oblong, 2 to 5 in. long, with broadly sessile 

 or clasping base, those of the flowering branches much reduced, 

 oblong-ovate, entire or serrulate; involucral bracts lanceolate without 

 spreading tips. 



Salt marshes about San Francisco, San Pablo and Suisun Bays. 

 Aug.-Nov. Stems sometimes flexuous. 



Var. paludosa (G-. paludosa Greene). Five ft. high, with sufiru- 

 tescent stems 1 to 2 ft. high lasting through the winter; cauline 

 leaves sometimes triangular-oblong, with subauriculate clasping 

 base. — Heart of the Suisun Marshes. - 



78. PENTACH/ETA Nutt. 



Low and very slender annuals with narrowly linear and entire 

 alternate leaves. Heads small, solitary, or somewhat clustered at 

 the ends of more or less naked branches, nodding in the bud. Eeeep- 

 tacle convex. Involucre turbinate-campanulate, its bracts in 2 series, 

 narrowly oblong, thin or membranous, scariouB-margined, mucronu- 

 late, appressed. Disk-corollas yellow or rose-red, very slender; rays 

 white, pink or yellow, or none. Achenes oblong, flattened, hirsute- 

 pubescent. Pappus of 5 slender bristles, often with 2 reduced or 

 wanting, or all obsolete. (Greek pente, five, and chaite, a bristle, in 

 allusion to the pappus.) 



Simple or with simple branches from the base, erect; peduncles white- 



villous beneath the head .1. P. exilis. 



Dlchotomous, and disposed to be diffuse; peduncles with scattered hairs . 



2. P. alsinoides. 



1. P. exilis Gray. Simple or mostly branched from the base, 

 erect, commonly 3 or 4 in. high; herbage purplish; branches or 

 stems terminated by a single head (IJ to 2 lines high); involucre 

 broadly campanulate; rays 8 to 14, 2 lines long; outer disk-corollas 

 rose-red, widening upward, the throat abruptly contracted beneath 

 the minute teeth; achenes oblong-turbinate, villous; pappus-bristles 

 3 or 5, sometimes abortive. 



Coast Kange hillsides: San Mateo Co. , Oakland Hills; Marin Co., 

 Napa Valley. Apr.-May. 



2. P. alsinoides Greene. Dichotomously branching, 2 to 5 in. 

 high; involucres narrowly or broadly turbinate, its bracts 5 to 7 or 9 

 and containing 3 to 7 flowers; disk-corollas filiform, with minute 

 teeth; rays none; achenes obovate-clavate; pappus-bristles 3," very 

 slender. 



Coast Eanges: Berkeley Hills, Greene; Vallejo; Sonoma. Also in 

 the Sierra Nevada ace. to Gray. Apr.-May. 



79. HETEROTHECA Cass. 



Tall hairy herbs with alternate leaves and heads of yellow flowers 

 in a terminal corymbose panicle. Involucre hemispherical or broadly 

 campanulate, its narrow bracts closely imbricated in many series. 



