AcriNELLA. COMPOSITE. 383 



as the disk. The heads are rather larger than in the following species ; the 

 rays 12 or more, bright yellow, elliptical-oblong. The membranaceous 

 .scales of the pappus, 5 in number, are roundish-oval, obscurely 1-nerved, 

 and very abruptly awned, the awns short; in the ray similar but awnless. 



* * * Annual : stems branching, diffuse : leaves entire. 



7. A. UnearifoUa : somewhat pubescent with slender spreading hairs; pe- 

 duncles slender, terminating the spreading branches; leaves narrowly linear, 

 the lowermost oblanceolate, attenuate at base; scales of the involucre oblong, 

 obtuse, pubescent, in 1-2 series; scales of the ])a[)pus 5-6, ovate, entire, 

 tipped with slender awns. — Hymenox3's ? linearilblia, Hook. ic. jjI. t. ]46; 

 DC. 2Jrodr. 7. p. 243. 



Texas, Drummond ! Western Louisiana or Arkansas, Dr. Leavenworth! 

 — Plant slender, 6-12 inches high. Heads one-half to two-thirds of an inch 

 in diameter, including the 8-9 rather large obovate-oblong rays, wjiich are 

 apparenlly pale yellow. Receptacle conical. Achenia villous. The heads 

 exhale the odor of Chamomile when bruised, as in Hymenoxys. Although 

 an annual, it is doubtless a congener of the preceding species. 



126. AMBLYOLEPIS. DC. prodr. 5. p. 667. 



Heads many-flowered, radiate ; the ray-flowers ligulate, pistillate, in a 

 single series, 3-cleft at the apex ; those of the disk tubular, perfect. Scales 

 of the involucre in two series; the exterior 6 or 7, ovate, acute, foliaceous, ap- 

 pressed, as long as the disk ; the inner roundish-obovate, very obtuse, hyaline, 

 nerveless. Receptacle flattish, alveolate. Corolla of the disk with a short 

 tube and an inflated throat, 5-lobed ; the lobes lanceolate, callous-apiculate. 

 Anthers with long acute appendages. Branches of the style not appendicu- 

 late. Achenia turbinate, very villous with appressed hairs. Pappus of 5 

 very obtuse nerveless scales in a single series, as long as the tube of the co- 

 rolla. — An annual erect and simple herb, sparingly hairy along the stem, the 

 margins of the leaves, and the scales of the involucre. Leaves alternate, 

 partly clasping, not decurrent, oval-lanceolate, nearly entire. Heads termi- 

 nal, solitary, of the size and aspect of Pyrethrum Myconis. Flowers 

 yellow. DC. 



A. setigera (DC. 1. c.) 



Texas, between Bexar and Austin, Berlandier. — A foot high. Leaves 

 few; the lower obtuse, the upper acuminate, DC. — We have seen this plant 

 only in the herbarium of De Candolle. 



127. HELENIUM. Linn. ; Lam. ill. t. 688; DC. prodr. 5. p. 665. 



Heads many-flowered, radiate ; the ray-flowers in a single series, pistillate, 

 ligulate, cuneiform, 3-5-cleft at the summit, nearly or quite destitute of a 

 tube. Scales of the involucre in 2 series ; the exterior linear or subulate, 

 foliaceous, spreading or reflexed ; the interior fewer and much shorter, chaffy. 

 Receptacle convex, globose, or oblong, naked. Corolla of the disk with an 

 extremely short proper tube, and a cylindraceous inflated 4-5-toothed throat ; 



