374 COMPOSITAE. 



512. HEMIZONELLA. 



Small loosely branched annuals with linear opposite or the 

 upper alternate leaves; heads with 4 or 5 ray flowers and 1-4 

 disk flowers; involucre of 4 or 5 obcompressed incurved tegules, 

 each enclosing an akene; bracts of the receptacle 3-5, united 

 into a cup; ligulate flowers minute, yellow; akenes obovoid, 

 broad and convex on the back. 



Hemizonella durandi Gray. Herbage more or less hirsute, glandular near 

 the top; stems 5-15 cm. high, loosely branched; leaves linear, 10-15 mm. long; 

 earliest heads in the forks of the branches, slender- peduncled, bractless, the 

 later ones racemose, 2-bracted at base, or short-peduncled; akenes hairy, 

 oblong-ovate or subfusiform, tipped with an inflexed beak. 



In dry ground, not common, Vancouver Island to California. 



513. HEMIZONIA. 



Mostly annual herbs, usually more or less glandular and viscid 

 and heavy-scented; leaves alternate or sometimes opposite; 

 heads not large, many- or sometimes few-flowered; tegules 

 rounded on the back, partly enclosing the turgid more or less 

 oblique ray-akenes; disk-akenes abortive or infertile. 



Hemizonia pungens (Hook. & Arn.) Torr. & Gr. Hairy, but only slightly 

 glandular; stems 30-60. cm. high; basal leaves bipinnatifid; cauline simply 

 pinnatifid, the lobes lanceolate or linear-lanceolate, entire, very sharp-pointed; 

 the leaves on the branchlets entire, small and crowded, rigid, spine-tipped; 

 tegules lanceolate, spine-tipped; receptacle convex; rays short, narrow, toothed 

 at the apex; pappus none. 



Sparingly introduced; a native of California. Tacoma, Flett. 



514. LAGOPHYLLA. 



Annuals; stem slender, much-branched; leaves alternate or 

 opposite, mostly entire; heads small, few-flowered; ray-flowers 

 about 5, pistillate, fertile ; disk-flowers as many, perfect but sterile; 

 involucre of as many tegules as the ray-flowers; receptacle 

 small and flat; pappus none; ray-akenes obovate, much ob- 

 compressed, smooth, enclosed by the base of the tegule; disk- 

 akenes slender and abortive. 



Lagophylla ramosissima Nutt. Erect, loosely branched, 15-70 cm. high; 

 stems light colored, puberulent; leaves all but the lowest attenuate, entire, 

 linear-lanceolate or the lowest somewhat spatulate, 1-3 cm. long, all white 

 villous; heads 5-6 mm. long, in small clusters on the leafy branches; tegules 

 ciliate with long hairs, and usually bearing a few stalked glands on the back; 

 ray-flowers yellow, small; akenes 3 mm. long, club-shaped, with a ridge down 

 the inner face. 



Prairies, Willamette Valley and southward. 



515. BIDENS. BEGGAR TICKS. 



Annual or perennial herbs; leaves opposite; heads small or 

 medium, yellow or sometimes white; ray-flowers 3-10, sterile or 



