1907 1 Hall. Compositae of Southern California. 275 



118. LYGODESMIA Don. 



Herbs, mostly with glabrous rush-like tough stems and narrow 

 leaves. Heads scattered or terminal, erect, 3 to 12-flowered. 

 Flowers pink or rose-color. Achenes slender, terete, obscurely 

 striate or angled, truncate at each end. Pappus of numerous 

 unequal white or whitish capillary bristles, not plumose. 



1. L. exigua Gray, Proc. Am. Acad. ix. 217 (1874). Pren- 

 anthes exigua Gray, PL Wright, ii. 105 (1853). 



A diffusely branched glabrous annual, 1 to 3 (or 5) dm. high: 

 leaves mostly basal, oblanceolate, entire or dentate, or pinnatifid 

 with sharp lobes, 2 or 3 cm. long, the upper reduced to scale-like 

 bracts : heads on slender peduncles : involucre 5 mm. high ; its 

 principal bracts about four, linear-oblong, acute; the calyculate 

 ones few and very short : achenes scarcely longer than the copious 

 white pappus-bristles. 



Rabbit Springs, Mohave Desert, Parish, where it is probably 

 not uncommon; Paloverde Valley, Riverside Co., near the Colo- 

 rado River, Hall, no. 5918; Colorado Desert, Stephens; Lower 

 California, Brandegee; Inyo Co., in the Argus Mts., Purpus, no. 

 5319 ; Panamint Mts. and Owens Valley, ace. to Coville ; thence 

 to Utah and New Mexico, ace. to Gray. 



L. SPINOSA Nutt., a spinescent perennial with matted-woolly 

 base has been reported from the eastern borders of California, 

 but has probably not been collected within our limits. It is not 

 rare in Inyo Co. 



119. TROXIMON Nutt. 



Perennial herbs with strong and often deep taproots, or an- 

 nuals. Stems nearly naked and scape-like, bearing single large 

 heads. Leaves in a radical tuft or a few scattered on the stem 

 below, elongated. Bracts of the campanulate involucre imbri- 

 cated, the outer ovate or narrower ; the inner ones linear or lan- 

 ceolate. Flowers, in our species, yellow. Achenes terete, oblong, 

 or fusiform, 10-ribbed, narrowed above, in all of our species 

 prolonged into a slender or filiform beak. Pappus-bristles fine, 

 copious, inserted on the dilated apex of the beak. Achenes in 



