COMPOSITE FAMILY 253 



lanceolate, sessile. Heads % to 1 in. across. Rays over 100, 

 white, scarcely y^ in. long. Pappus double. — Occurs on low, 

 moist ground, but more common in the eastern states. 

 E. philadelphicus L., is a similar species of the foothills; 

 flowers larger, pink; pappus simple. 



13. E. armeriaefolius Turcz. Stems erect, 3 to 15 in. high, 

 from a biennial root. Leaves elongated, linear, 1 to 5 in. long, 

 pale, glabrous or with a few long loose hairs. Heads ^ in. 

 across; bracts mostly equal. Rays whitish, abundant but very 

 short and thread-like. — Tuolumne and other high meadows. 

 Perhaps also in Yosemite Valley. 



14. E. canadensis L. Horseweed. Stem simple, erect, 2 to 

 6 ft. high, from an annual root. Leaves linear to lanceolate, 

 2 to 3 in. long, green, glabrous or with a few hairs. Heads 

 scarcely % in. across, with unequal bracts and many minute 

 white rays but apparently discoid. — A common weed in Cali- 

 fornia, rarely reaching 4000 ft. alt. in the mountains. 



14. PSILOCARPHUS. 



1. P. tenellus Nutt. A small forked woolly annual, only 1 

 in. or less high. Leaves opposite, narrow, Y\ to ^2 in. long, 

 the upper ones exceeding the sessile heads. Outer flowers 

 enclosed each in a loose sac-like bract; inner flowers without 

 bracts. Pappus none. — Yosemite Falls to the foothills. 



Filago californica Nutt., may appear along our lower bor- 

 ders. It is a slender, erect, woolly annual, only the inner 

 flowers of each head pappus-bearing. 



15. ANTENNARIA. 

 Perennial woolly herbs with alternate sessile entire leaves 

 (chiefly basal). Heads small, without rays, the bracts papery 

 and imbricated. Pistil-bearing and stamen-bearing flowers 

 borne on separate plants, the former with pappus-bristles 

 united at base, the latter with pappus-bristles thickened at tip. 



1. A. argentea Benth. A leafy-stemmed perennial, 9 to 18 

 in. high. Lower leaves spatulate, 1 or 2 in. long, y^ to ^2 in. 

 wide, upper ones narrower. Heads %. in. high, numerous, in 

 rounded terminal clusters, the bracts greenish white. — In open 

 forests at low altitudes; common from Wawona to Hetch 

 Hetchy Valley. 



2. A. media Greene. A matted perennial, 2 or 3 in. high. 

 Leaves spatulate, acute, *4 to l A in. long. Heads in small 

 dense terminal clusters, the bracts green but with lighter tips. 

 — Abundant near timber-line and above. 



