150 



POLYGON ACEJE . 



Involucral teeth equal or the three alternate shorter. 

 Erect plants. 



Calyx-segments equal, nearly distinct; involucre with broad scarious margin 



1. C. membranucea. 



Calyx-segments very unequal, the alternate shorter; involucral margin 



none 2. C. valida. 



Calyx shortly cleft, segments equal; involucral margin none or scanty . . . 



3. C. robusta. 



Erect or diffuse plants; involucral margins pink or white; calvx shortly cleft; 



segments equal 4. C. Douglasii. 



Prostrate plants; calyx segments equal. 



Involucre usually margined; stamens 9 5. C.pungens. 



Involucre not margined; stamens 3 G. C. Cleveland!. 



Involucral teeth very unequal, 1 long and 5 very short; prostrate 



7. C. uniaridata. 



1. C. membranacea Benth. Erect, 6 to 12 or 14 in. high, 

 un branched, or once or twice dichotomous at the summit of the stem; 

 herbage lanate throughout, floccose in age, the upper surface of the 

 leaves glabrate; internodes about 2 in. long; leaves \ to 1} in. long, 

 linear, sessile, or gradually narrowed into a short petiole; involucres 

 condensed into dense head-like cymes, these solitary in the upper 

 axils and terminating the branches; margin of the involucre wholly 

 scarious between the awned teeth; awns slender, uncinate, and 

 strongly divergent; flow 7 ers 2 to 3, of these 1 or 2 undeveloped or 

 nearly obsolete; calyx-segments distinct, broadly obspatulate with 

 long narrow claw. 



Inner Coast Ranges from the Vaca Mountains to Mt. Diablo. 



2. C. valida Wats. Erect, 4 to 6 in. high, once or twice di- or 

 tri-chotomously branched; leaves spatulate; involucral teeth or lobes 

 not margined but aw'ned; awns mostly straight; inflorescence similar 

 to the preceding; flowers pedicellate, partly exserted; calyx segments 

 oblong, erose-denticulate, hirsute along the back on the midvein, 

 very unequal (the alternate only \ as long). 



Sonoma, Samuels; Petaluma; Russian River. Rarely collected. 



3. C. robusta Parry. Stout, 6 to 24 in. high, ternately and 

 dichotomously branched above, the stem below bearing two or three 

 whorls of spatulate leaves, 2 in. long or less; heads large, dense, 

 mostly terminal or sub-terminal; involucres with narrow margins or 

 none, teeth mostly uncinate, the alternate shorter; calyx cleft ^ the 

 way down, slightly exserted or not at all; segments equal, oblong, 

 apiculate. 



Sandy soil at Alameda and near Santa Cruz. Apparently a good 

 species but not well marked save by its erect habit and regular 

 branching. 



4. C. Douglasii Benth. Erect, with slender diffuse branches from 

 the base or more commonly simple below the first or second nodes, 3 

 to 10 in. high, pubescent throughout; radical leaves oblanceolate; 

 cauline similar but reduced above, 3 to 6 lines long; involucres 

 in small loose clusters, each \\ lines long, densely hairy in the 

 furrows, with pink scarious margins and straight or uncinate awns; 

 calyx segments apiculate, the alternate often emarginate; hairy on 

 the back. 



