ASTERACEAE. 411 



basal leaves pinnatifid; heads numerous; involucre about 6 mm. high, 

 narrow, few-flowered; bracts usually purplish-tipped; flowers yellow; 

 achenes oblong-linear, minutely striate-costate, 4-5 of the ribs more 

 prominent; outer pappus of 1 persistent bristle and a conspicuous 

 circle of narrow white setulose teeth. 



Occasional in the San Gabriel Mountains. More common^ in 

 the mountains and foothills of Riverside and San Diego Counties. 

 May-July. 



3. M. saxatilis tenuifolia (Nutt.) Gray. Somewhat suffrutescent 

 and leafy, paniculately branching, perennial, minutely tomentose, 

 soon becoming glabrate or glabrous, 6-12 dm. high; the long slender 

 loosely- paniculate branches bearing slender pedunculate heads; 

 involucre broadly campanulate, about 1 cm. high; the loose calycu- 

 late bracts numerous, subulate, passing into similar bractlets on the 

 peduncle; flowers white, changing to rose color; achenes narrowly 

 oblong, 10-15 costate, becoming somewhat 4-5-angled, apex slightly 

 contracted, bearing a very short multidenticulate white border. 



Common in stony places in the foothills, especially toward the 

 coast. April-May. 



78. LEONTODON L. Dandelion. 



Perennial acaulescent herbs, with basal pinnatifid or 

 sinuate-dentate leaves, and large heads solitary on 

 hollow scapes. Involucre oblong or campanulate, its 

 inner bracts in 1 series, erect, the outer short in several 

 series and spreading. Receptacle flat, naked. Rays 

 5-toothed at the apex. Achenes oblong or narrowly 

 fusiform, 4-5-angled, 5-10-nerved, roughened or spinu- 

 lose above, tapering into a very slender beak. Pappus 

 of numerous unequal simple persistent bristles. {Tar- 

 axacum.) 



1. L. taraxacum L. Perennial acaulescent herb, with pinnatifid 

 or sinuate leaves, and large heads of yellow flowers terminating 

 naked hollow scapes; involucral bracts of two sorts, the outer reflexed, 

 the inner erect in a single series; achenes greenish-brown, oblong- 

 ovate, 4-5-ribbed, spinulose above, attenuated into a long slender 

 beak; pappus of numerous unequal simple capillary bristles. 



The common Dandelion is becoming frequent in lawns. 



2. L. erythrospermum (Andrz.) Britton. Resembles the com- 

 mon Dandelion, being best distinguished by the red instead of 

 greenish-brown achenes. 



This species is frequent in the San Francisco Bay region, and is 

 to be expected in the lawns of southern California as well. 



79. SONCHUS L. Sow-thistle. 



Annual succulent herbs with alternate mostly auricu- 

 late-clasping entire or pinnatifid prickly-margined leaves 



