THISTLE FAMILY 953 



P. florihunda Greene. Dry and gravelly soil; Wyo.— Tex.— Ariz.— Utah. Plain 

 — Mont. Je-Au. 



6. H. Earlei Cockerell. Stem 2-3 dm. high, corymbosely branched above; 

 leaves pinnatifid into 3-5 narrowly linear divisions, somewhat broader than in 

 the preceding; involucres 5-6 mm. high, 7-8 mm. broad; outer bracts united 

 about one-third their length, lanceolate; inner bracts barely mucronate. P. 

 Earlei Cockerell. Foot-hills and canons: s Colo. Suhmo?iL Jl. 



7. H. canescens (D. C. Eat.) Cockerell. Stem 1-2 dm. high, canescent 

 with flat scale-hke hairs; leaves numerous, 2-4 cm. long, divided into 3-5 linear- 

 filiform divisions, canescent like the stem, rather fleshy; involucre 5-6 mm. high, 

 10-15 mm. broad; outer bracts 12-15, lanceolate; liguJes about 8 mm. long, 3 mm. 

 wide. A, Richardsonii canescens D. C. Eat. Dry places: Nev.- — Utah, Son. 



8. H. biennis (A. Gray) H. Hall. Biennial; stem 3-5 dm. high, more or less 

 grayish-puberulent; leaves numerous, pinnatifid, with narrowly linear divisions 

 1-1.5 mm. broad, puberulent; involucres 6 mm. higli, 10-15 mm. broad; inner 

 bracts obovate or oblanceolate, usually with one small tooth on each side; ligules 

 fully 1 cm. long, orange, cuneate. A. biennis A. Gray. Arid regions: s Utah — 

 Ariz. L. Son. 



9. H. Greenei (Cockerell) Rydb. Stem about 3 dm. high, with erect branches, 

 leafy, glabrous; leaves pinnatifid; divisions linear, 2-4 mm. broad; involucres 

 about 6 mm. high and 10-13 ram. broad; inner bracts broadly obovate, more or 

 less erose-dentate ; pappus-scales lanceolate, graduallj^ aristate. H. Lemmonii 

 Greenei Cockerell. Arid regions: s Utah — Nev. — Ariz. Son. 



10. H. helenioides Rydb. Biennial; stem leafy, about 5 dm. high, yvith 

 several to many erect branches; leaves rather firm, distinctly ribbed, finely 

 pubescent; basal leaves entire, very narrowly linear-oblanceolate; middle stem- 

 leaves erect, fully 1 dm. long, parted into 3-5 linear divisions; upper stem-leaves 

 linear, entire; involucre 8-10 mm. high and often 15 mm. broad; outer bracts 

 lanceolate, longer than the inner, 14—18 in number; ligules orange, about 1 cm. 

 long, 2-3 mm. wide. River valley: s Colo. Mont. Jl. 



11. H. odorata DC. Stem branched near the base, 1-3 dm. high, sparingly 

 pilose or glabrous; leaves pinnatifid, with hnear-filiform divisions; involucres 

 about 4 mm. high, 6-8 mm. broad; ligules cuneate, 3-5 mm. long; pappus-scales 

 ovate, aristate. Philozera multiflora Buckley. Picradenia midiifiora Greene. 

 A. odorata A. Gray. Dry plains: Tex. — Kans. — Colo. — ^Ariz. Son, Je-Au. 



108. TLAVERIA Juss. 



Glabrous or puberulent herbs. Leaves opposite, narrow, entire or dentate, 

 sessile, often more or less connate. Heads numerous, narrow, in dense cymes 

 or glomerules. Involucre of 1-8 subequal bracts, and sometimes 1 or 2 smaller 

 outer ones. Receptacle small, naked or setose. Ray-flowers solitar\% pistillate 

 and fertile, or wanting; ligules entire, emarginate, or 3-dentate, yellow, incon- 

 spicuous. Disk-flowers 1-15, hermaphrodite and fertile. Style of the herma- 

 phrodite flowers 2-parted, reflexed, obtuse. Achenes oblong, somewhat com- 

 pressed, 10-ribbed; pappus in ours wanting. 



1, F. campestris J. R. Johnston. Annual; stem 2-6 dm. high, glabrous; 

 leaves lanceolate to linear, serrulate to entire, more or less distinctly 3-ribbed; 

 heads in close, subsessile clusters at the ends of the branches, 2-5-flowered; invo- 

 lucres cylindric, about 5 mm. long; bracts mostly 3, linear-oblong, glabrous; 

 ligule elliptic, 1.5-2 mm. long, exceeding the disk. F. angustifolia A. Gray, not 

 Pers. Alkali grounds: Tex.— Colo.— N.M.; Mex. Son. Jl-Au. 



109. DTJGALDIA Cass, 



Perennial caulescent herbs, with rootstocks, more or less floccose or villous. 

 Leaves linear, entire, not decurrent, with several nearly parallel nerves. Heads 

 radiate, large. Involucre almost rotate; bracts lance-subulate, herbaceous, in 2 

 or 3 subequal series, spreading and tardily reflexed. Receptacle convex or nearly 



34* 



