426 COMPOSITiE. 



leaves mostly entire, linear, less than 1 in.lougr: rays 12 — 15; ray-achenes 

 with prominent upturned beak; pappus of sterile disk-achenes none, or 

 a row of minute bristles rather than scales. — Less frequent than the 

 preceding, and of the same range. 



(>4. HOLOCARPHA. Rigid upright branching annual, the serrate 

 or entire leaves not pungent, the upper gland-tipped, the subglobose 

 heads solitary or glomerate. Receptacle convex, the numerous flowers 

 each subtended by a persistent bract, the outer and involucral ones 

 beset on the back with prominent stout clavate and gland-tipped pap- 

 illje. Rays diurnal, numerous, narrow, their achenes half-enclosed by 

 their bracts, obovate-triquetrous, nearly smooth, obtusely 4-angled on 

 the back, the one ventral angle ending above in a short beak. Disk- 

 tiowers sterile. Pappus none. 



1, H, macradema^ Heynizonia macradenia, DC. Prodr. v. 693 (1836). 

 Stout, hirsute, viscid-glandular, 1 — 2 ft. high, leafy below, parted 

 abruptly above the middle into few and widely diverging spicate 

 branches: leaves linear, sharply laciniate- toothed or entire, the chaff of 

 receptacle, floral bracts and uppermost leaves linear-subulate, abruptly 

 gland-tipped and more or less beset with smaller gland-tipped hairs: 

 heads often sessile and glomerate, J^ in thick: ray-flowers very many, 

 with short yellow ligules: achenes dull-black, scarcely rugose or glan- 

 ular, with an angle on the ventral face and 5 dorsal nerves; the apicula- 

 tion very short. — Rich open ground about San Francisco Bay and south- 

 ward. Aug., Sept. 



65. CENTROMADIA, Greene. Rigid corymbosely or diffusely branch- 

 ing annuals, with alternate pinnatifid or entire spinescent foliage and 

 involucral bracts; the whole plant more or less resiniferous or glandular 

 and scented. Receptacle convex, chaffy throughout and tbe bracts dis- 

 tinct, persistent. Bracts of involucre subulate, pungent, embracing the 

 ray-achenes, persistent. Ray-flowers 30—40, small, open all day; their 

 achenes destitute of pappus, triangular, the inner angle terminated by a 

 short apiculation, the whole surface nearly smooth, or faintly rugose- 

 tuberculate. Disk-achenes mostly sterile and with or without a pal- 

 eaceous pappus. 



* Herbage yellowish-green, scentless, or with aromatic or sweet odor. 

 ■i^No pappus to disk-achenes. 



1. C. pun^ens, Greene, Man. 196 (1894); H. & A. Bot. Beech. 357 

 (1836), under Hartmannia. Erect, 2—4 ft. high, stout and with rigid 



