952 CARDUACEAE 



mucronate. Ray-flowers 5-lG, pistillate and perfect; ligules usually conspicuous, 

 3-lobed. Disk-flowers many, hermaphrodite, perfect. Style-branches obtuse 

 or truncate, penicillate. Achenes obpyramidal, 5-an^led, densety hirsute with 

 ascending hairs. Pappus of 5 hyahne squamellae, with faint or indistinct mid- 

 rib, usually acute or acmninate. [Picradenia Hook.] 



Perennials or biennials; inner bracts fimbriate or erose, abruptly acute, acuminate, or 

 f -^ mucronate, unlike the outer ones; disk-coroUa-s not expanded at the mouth. 

 Plant low, perennial, usually with a multicipital caudex; outer bracts united at least 

 one-tliird their length; plant long-hairy on the basal leaf-bases. 

 Outer bracts not strongly tliickened on the back. 



Outer bracts united to the middle; free portions ovate or ovate-lanceolate. 



1. H. Richardsonii. 

 Outer bracts united about a third their length; free portions narrowly lance- 

 olate. 



Involucre 10-15 mm. broad; ligules 10-18 mm. long; plant 1-3 dm. liigh. 



2. //. macrantha 

 Involucre 8-10 mm. broad; Ugules 5-8 mm. long; plant less than 1 dm. 



high. 3. H. pumila. 



Outer bracts strongly thickened on the back, subcarinate. 



Heads few, often sohtary; hguies nearly rectangular-oblong. 



4. H. Macounii. 

 Heads several; Ugules decidedly ctmeate. 



LigiUes light yellow, at least twice as long as wide; pappus-squamellae 



aristate-pointed. 5. H. floribunda. 



Ligules orange, half longer than wide; pappus-squamellae acute or acmn- 

 inate. 6. H. Earlei. 

 Plant tall, biennial or short-Uved perennials-, outer bracts united only at the base. 

 Leaves all dissected into narrowly linear divisions. 



Leaves of the stem very numerous, more or less lepidote-pubescent ; segments 

 narrow, rarely more than 1 mm. wide. 

 Plant low, densely canescent; heads 1-3; squamellae not more than half 



as long as the corolla, not subulate-tipped. 7. H. canescens. 



Plant tall, greener; heads several or many; squamellae about half as long 

 as the corolla, subulate-tipped. 8. H. biennis. 



Leaves of the stem not conspicuously nmnerous, glabrate and green ; segments 

 1-3 mm. wide. 9. H. Greenei. 



Leaves, at least the lower ones, entire or with broad lobes 3-8 mm. wide. 



10. H. helenioides. 

 Annuals, ^ith numerous heads ; inner bracts not very different from the outer, neither 

 abruptly acute nor mucronate, nor evidently erose; throat of the disk-corollas some- 

 what fimnelform. 11. H. odorata. 



1. H. Richardsonii (Hook.) Cockerell. Stem 1-3 dm. high, glabrous or 

 nearly so; leaves 5-10 cm. long, pinnatifid, with narrowly linear divisions 2-4 

 cm. long and 1-2 mm. wide; involucres about 8 mm. high and 10-15 mm. broad; 

 ligules bright yellow, 7-10 mm. long. Picradenia Richardsonii Hook. Actinella 

 Richardsonii Nutt. Hymenopappus ligulaeflorus A. Nels. P. ligulaeflora A. 

 Nels. Dry plains: Sask. — Mont. — Alta. Plain. Je. 



2. H. macrantha (A. Nels.) Rydb. Stem 1-2 dm. high, sparingly pubes- 

 cent or glabrate, hairy-tufted at the base; leaves glabrate, pinnatifid, with nar- 

 rowly linear divisions; involucres 10-15 mm. broad and 8 mm. high; inner bracts 

 obovate, abruptly short-acuminate, tips often greenish; ligules 8-18 mm. long, 

 bright yellow. Picradenia macrantha A. Nels. Dry soil: Wyo. — Colo. — Utah. 

 Plain^Mont. Je-Au. 



3. H. pumila (Greene) Rydb. Stem 1 dm. high or less, glabrate or shghtly 

 hairy; leaves pinnatifid, with 3-5 linear-filiform divisions, or the lower entire 

 and filiform; involucres 8-10 mm. broad, 5-6 mm. high; inner bracts ovate, with 

 short but sharp acummation; ligules pale yellow, 5-6 mm. long. P. pumila 

 Greene. Dry hills: Wyo. — -Colo. — Utah. Submont. Jl-Au. 



4. H. Macounii (Cockerell) Rydb. Stem about 1 dm. high, sparingly 

 pubescent or glabrous; leaves pinnately divided unto 3-5 filiform divisions; invo- 

 lucres about 6 mm. high and 8-10 mm. broad, usually acute at the base; ligules 

 bright yellow, 5-7 mm. long. Dry plains: Sask. — Mont. Plain. Je-Au. 



5. H. floribunda (A. Gray) Cockerell. Stem 1-3 dm. high, corymbosely 

 branched; leaves pinnatifid, with 3-5 narrowly linear divisions; involucres 4-6 

 mm. high, 6-8 mm. broad; outer bracts scarcely united to the middle, lanceolate; 

 ligules 6-8 mm. long, bright yellow, cuneate. A. Richardsonii floribunda A. Gray. 



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