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tifid or incised: achenes mostly terete and even, the ribs or nerves few and mostly 
obscure.—Rocky and sandy prairies of eastern and southern Texas, 
2, A. humilis Gray. Low and diffuse, soft-pubescent and cinereous: leaves rarely 
entire, often pinnatifid: achenes shorter and more distinctly costate-angulate.— 
Southern and western borders of Texas. 
** Pappus more conspicuous and dentate or laciniate : base of corolla-tube in age promi- 
nently thickened and indurated, long-persistent on the strongly angulate-costate achene, 
3. A. Arkansanus Gray. Diffuse, 3 dm, high: leaves oblong-spatulate to broadly 
lanceolate, the lower often toothed or lobed: rays about 12 mm. long: pappus mostly 
obtusely 4 or 5-lobed.—Plains of eastern and southern Texas. A Texan form is var. 
Hau Gray, which is somewhat smaller, with leaves varying from entire to pin- 
nately parted, and the pappus-crown more conspicuous and deeply cleft into 4 or 5 
unequal subulate-acuminate lobes. 
25. KEERLIA Gray. 
Diffusely and slenderly branched leafy-stemmed herbs, with small 
paniculate heads on almost capillary peduneles, white or purple rays, 
oblong entire sessile leaves, narrowly campanulate or turbinate invo- 
lucre with thin membranaceous scarious-margined bracts imbricated in 
a few series and of unequal length, flat receptacle, obovate and com- 
pressed 2 or 3-nerved achenes, and minute coroniform pappus (or evan- 
escent from the mature achenes). 
1. K. bellidifolia Gray & Engelm. Annual, pubescent, effusely branched from 
near the base: lower leaves obovate or spatulate; uppermost somewhat linear: invo- 
lucre only 2 lines long: rays 4 to 15, blue.—Fertile soil, central Texas. 
2, K. effusa Gray. Perennial, taller (often 6 dm. high), with simple stem branch- 
ing above into an effuse panicle: leaves hispid (as well as the stem), rigid and sca- 
brous, oblong, mostly with broad sessile base: heads very numerous: rays 4 to 7, 
white.—Hillsides, central Texas. 
26. CHASTOPAPPA DC. 
Low branching annuals, with narrow entire leaves, solitary terminal 
heads, white or purple rays, several-flowered heads (disk-flowers 
often sterile), involuecral bracts imbricated in 2 or more rows (the outer 
shorter), flat naked receptacle, fusiform or compressed achenes, and 
pappus of 5 or fewer thin nerveless scales alternating with rough bristly 
awns, or these wanting. 
1. C. asteroides DC. Slender, 5 to 25 cm. high, pubescent: involucre 4mm. long, 
rather narrow: rays 5 to 12: disk-flowers 8 to 12: achenes slender, little compressed, 
obscurely few-nerved, pubescent, all the central ones sterile and often awnless: scales 
of the pappus very thin and hyaline, narrowly oblong, not rarely lacerate or cleft.— 
Dry ground, eastern and central Texas. In eastern Texas is var. IMBERBIS Gray, 
with awns of the pappus wanting in all the flowers, and the pappus-scales rather 
broader and sometimes more or less united. 
2. C.ParryiGray. More rigid, 20cm. ormore high: leaves hispidulous and glabrate : 
involucre 6 mm. long, turbinate: rays 6 or 7: achenes quite glabrous ; the fertile ones 
fusiform and somewhat compressed, 4-nerved, with a pappus of 4 or 5 cuneiform- 
quadrate scales which are laciniately fimbriate at the truncate apex, and of a few or 
sometimes solitary more delicate awns, these occasionally longer than the scales, 
sometimes wanting; disk achenes mostly awnless,—On the Rio Grande. 
