186 
appressed bracts, achenes of the ray sparsely villous, 3-angled with a 
strong rib at each angle, and pappus of numerous unequal rigid capil- 
lary bristles, those of the disk abortive, with pappus of very few 
(usually 2) bristles somewhat chatty below. 
1. B. hirtella Torr. & Gray. Slender branches terminated by single rather small 
heads of yellow flowers: radical and lower cauline leaves narrowly spatulate; those 
of the flowering branches small, spatulate-linear to nearly filiform, mucronate- 
pointed: rays 6 to 12 mm. long.—Dry ground, throughout Texas. 
20. APLOPAPPUS Cass. 
Mostly herbaceous perennials (some more or less shrubby), with alter- 
nate leaves, usually radiate and always yellow flowers, many-flowered 
heads, hemispherical involucre of many usually closely imbricated 
bracts in several series, flat receptacle, short turbinate to linear achenes, 
and a simple pappus of numerous unequal bristles. 
* Heads very large, 2.5 em. or more in diameter. 
1. A. ciliatus DC. Annualor biennial, glabrous, 6 to 15 dm. high, leafy: leaves 
oval (or lower obovate), obtuse, dentate with bristle-pointed teeth: heads few and 
clustered, with very numerous rays, and the outer involucral bracts spreading: 
achenes glabrous, the central abortive.—Hillsides and river banks throughout Texas 
as far west as the Pecos. 
2, A. Nealleyi Coulter. Glabrous or nearly so, somewhat branching above, 3 to 6 
din. high, terminated by long mostly naked peduncles which are enlarged beneath 
the large solitary heads: leaves narrowly linear or almost filiform, entire or pinnat- 
ifid with 2 or 3 linear lobes: involucral bracts loosely imbricated: rays 10 to 15: 
achenes with rugulose sparsely pubescent striw.—Near Santa Maria, Cameron 
County. 
** Heads smaller, 6 lo 12 mm, high. 
+ Leaves more or less pinnatifid, with teeth and tips commonly bristle-tipped: involucral 
bracts narrow and well-imbricated. 
++ Leaves not deeply cleft. 
8. A. aureus Gray. Minutely scabrous-glandular, 1 to 3 dm. high: leaves all nar- 
rowly linear, sparingly pinnatifid-dentate: heads 8 mm, high, the outer involucral 
bracts with short deltoid-ovate green tips: rays 18 to 25: achenes sericeous.—Low 
plains near Houston (Wright). Said not to have been collected since. 
4. A. rubiginosus Torr, & Gray. Viscid-glandular and more or less pubescent, 
8 to 9 dm. high: leaves lanceolate or narrowly oblong, incisely pinnatifid or dentate 
with salient narrow teeth: heads somewhat paniculate, 10 to 12 mm. high, usually 
naked-pedunculate, the involucral bracts with slender spreading green tips: rays 
and achenes as in the last.—Low grounds, throughout southern and western Texas. 
Along the sea-beaches of southern Texas occurs var. PHYLLOCEPHALUS Gray, which is 
a lower spreading form, leafy up to the heads which singly terminate the branches 
and are larger and more or less leafy-involucrate. 
++++ Leaves 1 to 2-pinnatifid. 
5. A. gracilis Gray. Annual or becoming woody at base, canescently-pubescent 
(occasionally glabrate and scabrous), much branched: leaves linear or the lowest 
spatulate, pinnatifid, or the upper few-toothed or entire, tipped or also sparsely 
fringed with long and slender bristles: heads 8 to 10 mm. high, with 15 to 30 rays, 
and involucral bracts wholly appressed and mostly setaceous-tipped: achenes com- 
pressed.—Plains of western Texas. 
6. A. spinulosus DC. Perennial, canescent to glabrate, branched at summit: 
leaves broader in outline than in the last, pinnately and lower often bipinnately 
