234 DESCRIPTION OF ASTERS; DIVARICATI 
Petioles usually shorter than half the leaf-breadth. Veins 
slender, cord-like beneath, impressed above or slightly elevated 
when dry. Obvious hair absent, and but little to be found by 
lens except on pedicels. 
Branches numerous, long, rigid, ascending in straight or 
irregularly slight sinuous lines, each branch very loosely corym- 
bose or in larger plants pinnately branched with corymbs on the 
branchlets only. 
Inflorescence in well-developed plants paniculately decom- 
pound, very profuse, strongly pinnate in effect on pressing; the 
panicle often somewhat urceolate by outcurve at the base of up- 
rising branches. Still stronger plants rise higher, the inflorescence 
forming 24 of the plant or more; and assuming an elliptic or 
oblong form, more than 2 x t ft. long; of its dozen branches several 
becoming as much as 20 in. long. 
Pedicels (ultimate branchlets) filiform, stiff, 1 in. or 14 in. 
long, either with subtending linear or discule bractlets, and divari- 
cate widely or slightly according to number, their bases usually 
corymbosely separated, not umbelliform or subradiate as often in 
A. Claytoni. 3 
Heads very small, about 5g in. broad, 1% in. high, the involucre 
when dry being 1$; or in less floriferous plants all heads may be 
larger, 3$ in. high, 34 in. broad, etc. 
Involucre narrowly urceolate, contracted above during early 
flower, appearing as if pinched together just before the expanding 
summit, as also to some degree in A. Claytont. 
Bracts in general character lingual, very broad, rounded and 
scale-like, very uniform, with little herbaceous or green growth, 
reddened, especially at the edges, or straw-color throughout, with 
but slight ciliation, otherwise smooth; the pale green midrib 
abruptly terminated by a broad shallow inconspicuous crescentic 
green tip, absent from the inner half of the series; or the green 
tip subdeltoid and with no green color decurrent into the midrib. 
A few lowest bracts are sometimes slightly acutish ; a few inmost 
are slightly tapered to an obtuse apex. 
Rays dull white, sometimes reddened, persistently 8, oblong, 
tapered somewhat to both ends, obscurely tridentate at the apex; 
Some vigorous plants produce 10 rays; more often some.rays are 
missing. 
Heads very subject to malformation, many of them blasted in 
small plants, or with only a few rays and half the disk developed. 
Disks rather full, glowing, 20-flowered, the lobes very acute. 
Achenes often copiously hairy when young, seldom so at maturity; 
Pappus soon slightly reddened in the herbarium, decidedly so 
within 3 years. 
