406 COMPOSIT.E. 



pinnatifid, glabrate and green above, white-tomentose beneath: burs % 

 in. long, armed with short weak prickles. — By waysides, common; native 

 of tropical America. 



2. X. Canadense, Mill. Diet. 8 ed. (1768). Stout, branching above 

 only: leaves broad-ovoid, sligbtly lobed, scabrous: bur an inch long, 

 densely beset with stoutish prickles, and at apex strongly 2-horned. — In 

 low tields, where it may have been introduced; but also apparently 

 native, in more slender form, on dry ground, amid salt marshes. Aug. — 

 Oct. 



Suborder 5. HelianthacejE. 



Plants commonly with balsamic- resinous juice, and coarse roughish or 

 woolly foliage. Rays conspicuous; receptacle strongly chaffy; anthers 

 not caudate; involucre not scarious; pappus never of capillary bristles. 



Hints of the Cieiiera. 



Involucre of 1 or 2 .series of similar bracts; 



Hays small, white -.--.-._.-. 47 

 Rays large, yellow, or wanting -------- .48 



Involucral bracts imbricated in several series; 



Pappus none; aohenes oblong ---------- 49 



'■ of more or less united awns or paleae -------50 



" of two or more thin caducous paleas - - - - - - - 51, 52 



none; achenes obovoid, compressed - - - -- - -52 



Involucre double; outer series of bracts spreading, inner erect; 



Pappus not retrorsely barbed -------.-_ 54 



" retrorsely barbed or aculeolate ---------53 



47. ECLIPTICA, Rumphius. Flaccid low riparian herbs with oppo- 

 site leaves, and scattered small heads of whitish flowers. Involucre 

 broad, of one or two series of herbaceous bracts. Bracts of flatfish 

 receptacle reduced to awn-shaped chaff" or bristles. Eays short, fertile. 

 Achenes thick, those of the ray triquetrous, of the disk compressed, 

 margined. Pappus of 2 — 4 short teeth or awns or none. 



1. E. alba, O. Ktze. Eev. Gen. i. 334 (1891); Linn. Sp. PI. ii. 902 

 (1793), under Verhesina. Annual, 1 — 3 ft. high, decumbent, minutely 

 strigose - pubescent : leaves lanceolate or oblong, sparingly serrate, 

 sessile, or the lower short-petioled : peduncles from the upper axils long 

 or short; rays about equaling the disk; disk-achenes corky-margined, 

 truncate. — Banks of the lower Sacramento, Jepson. Sept., Oct. 



