244 
and few heads. Reported from Gillespie County (Jermy) is the northern var, DISCOLOR 
Gray, which is 6 to 18 dm. high, and with leaves nearly all deeply pinnatifid into 
lanceolate or linear labes. 
5. C. Virginianus Pursh. Stem woolly, slender, simple or sparingly branched, 3 
to 9 dm. high, the branches or long peduncles naked: leaves lanceolate, whitened 
with close wool beneath, ciliate with prickly bristles, entire or sparingly sinuate- 
lobed, sometimes the lower deeply sinuate-pinnatifid: heads small: outer involucral 
bracts scarcely prickly: flowers purple.—Pine woods and dry banks, extending 
from the Atlantic States into Texas. 
+ + Leaves green both sides, or only with loosecobwebby hairs beneath : involucral bracts 
scarcely prickly-pointed. 
6. C. Wrightii Gray. Robust and tall, with thin cobwebby wool tardily decidu- 
ous from the ample (3 dm. or more long) sinuate or pinnatifid weakly prickly leaves: 
heads in a naked panicle: involucral bracts small, the principal ones conspicuously 
viscid-glandular on the back, outer ones subulate and cuspidate-tipped: corollas 
white (?).—Near springs, southwestern Texas (Wright). 
113. CENTAUREA L. (STAR-THISTLE.) 
Herbs, with alternate leaves, single many-flowered heads, flowers 
all tubular (the marginal often much larger, as it were radiate, and 
sterile), bristly receptacle, ovoid or globose involucre with margined or 
appendaged imbricated bracts, obovoid or oblong achenes attached 
obliquely at or near the base, and setose or partly chatty pappus or 
none. 
* Achenes terete, 10-dentate: pappus of 10 long bristles and 10 short inner ones. 
1. C. benedicta L. Low branching annual, with clasping scarcely pinnatifid 
cut leaves, large sessile leafy-bracted heads, and yellow flowers (Cnicus benedictus 
L).—Introduced into waste grounds, at seaports and elsewhere, Rare, 
** 4dchenes compressed or 4-angled: pappus of copious similar but unequal bristles. 
29. C. Americana Nutt. Nearly glabrous annual: stem stout, mostly simple, 6 
to 18 dm. high, thickened under the naked head: leaves entire or mostly so, oblong- 
lanceolate, mucronate: involucre 2.5 to 3.5 em. broad, its very numerous bracts all 
with conspicuously fringed scarious appendages: flowers rose or flesh-color, the neu- 
tral marginal ones forming an ample ray: pappus bristles longer than the achene.— 
Extending from the plains of Arkansas and Louisiana through Texas to Arizona and 
adjacent Mexico. 
114. GOCHNATIA HBK. 
Shrubby plants, with alternate coriaceous leaves which are usually 
entire and tomentose beneath, heads of white flowers in sessile panicu- 
late fascicles, dry or coriaceous regularly imbricated involucral bracts, 
flat naked receptacle, corollas all alike and deeply 5-cieft into linear 
revolute lobes, oblong silky-villous achenes, and pappus of copious 
rather rigid capillary scabrous or barbellulate bristles. 
1. G. hypoleuca Gray. Rigid shrub, 18 to 24 dm. high: leaves oblong or oval, 
very short-petioled: glabrous and bright green above, finely white-tomentose be- 
neath (as also the branchlets): involucre 5 to 7-flowered, the flowers all perfect.— 
Southern Texas, between the Rio Frio and the Nueces, and at Laredo (Palmer), and 
in adjacent Mexico, 
