854 CARDUACEAE 



trumpet-shaped, deeply 5-lobed. Anthers obtuse at the base. Style-branches 

 stigmatic their whole length, with ovate to lanceolate-subulate appendages. 

 Achenes densely silvery-villous. Pappus of white capillary bristles, rather de- 

 ciduous. 



1. S. interior (Coville) Rydb. Shrub 3-10 dm. high; branches green, slightly 

 puberulent; leaves linear, fleshy, glandular-punctate, 1-2 cm. long; involucres 

 hemispheric, about 1 cm. high; bracts linear, attenuate, glandular-granuliferous; 

 ligules 9-11 mm. long, golden yellow. Aplopappus interior Coville. Hillsides 

 in desert regions: s Calif. s Utah Ariz. Son. Ap-Jl. 



20. OONOPSIS Greene. 



Perennial herbs with woody caudex or crown, and erect, leafy stems. Leaves 

 linear or lanceolate, entire. Heads in terminal cymes or solitary. Involucres 

 campanulate or hemispheric; bracts well imbricate, flat, cuspidate-acuminate. 

 Ray-flowers pistillate or wanting; ligules yellow. Disk-corollas yellow, cylindric, 

 with 5 short teeth. Tips of the style-branches ovate, shorter than the stigmatic 

 part. Achenes glabrous or strigose, many-nerved. Pappus of rather few coarse 

 bristles. 



Dwarf; stem less than 1 dm. high; heads 6-10 mm. high. 

 Plant more or less villous; leaves flat; heads radiate. 



Heads 6-8 mm. high; leaves 1-3 cm. long, not exceeding the stem. 



1. O. multlcaulis. 

 Heads 8-10 mm. high; leaves 4-8 cm. long, often overtopping the stem. 



2. O. argillacea. 

 Plant glabrous; leaves in volute; heads discoid. 3. O. Engelmannii. 



Plant robust, 1.5-3 dm. high; heads 15-20 mm. high. 

 Heads discoid. 



Heads clustered, 10-15 mm. high; achenes glabrous. 4. O. Wardii. 



Heads solitary, 15 mm. high or more; achenes glandular. 5. O. monocephala. 



Heads radiate. 6. O. foliosa. 



1. O. multicaulis (Nutt.) Greene. Stems several, 1 dm. high or less, 

 slightly villous; leaves narrowly linear, 1-3 cm. long, slightly villous, thick; 

 heads corymbose; involucres turbinate; bracts ovate, lanceolate or oblong, cus- 

 pidate-acuminate; ligules 5-6, 4^5 mm. long. Aplopappus multicaulis A. Gray. 

 Rocks: Wyo. Submont. 



2. O. argillacea A. Nels. Stems numerous, 5-8 cm. long, sparingly villous; 

 leaves entire, narrowly-linear, acute; involucres slightly villous, turbinate; bracts 

 oblong-ovate or lanceolate, acuminate; rays about 10; ligules 5-6 mm. long. 

 Clayey slopes: Wyo. Submont. Je-Jl. 



3. O. Engelmannii (A. Gray) Greene. Stems 1-2 dm. high, glabrous, leafy; 

 leaves narrowly linear, 3-5 cm. long, 2-3 mm. wide, rigid; heads rather many, in 

 a congested cyme, about 12 mm. high; involucres turbinate-campanulate, shorter 

 than the disk-flowers; bracts ovate or elliptic, short-cuspidate. Bigelovia Engel- 

 mannii A. Gray. Dry plains: Colo. Kans. Plain. Au-O. 



4. O. Wardii (A. Gray) Greene. Stems 1-2.5 dm. high, very leafy; leaves 

 broadly linear or lanceolate, 1-nerved, or 3-nerved at the base, 6-12 cm. long; 

 inflorescence dense, flat-topped; heads 15-25-flowered; bracts lanceolate, acumi- 

 nate. A. Fremontii Wardii A. Gray. 0. condensata A. Nels. Plains: Wyo. 

 Submont. Jl-S. 



6. O. monocephala A. Nels. Stems erect or ascending, 1-2 dm. high, leafy 

 to the summit; leaves glabrous, linear-oblong, sessile, acute, 5-8 cm. long, about 

 1 cm. broad; bracts oblong, abruptly acuminate, glabrous or ciliate on the mar- 

 gins. Plains: Colo. Plain. 



6. O. foliosa (A. Gray) Greene. Stems 2-3 dm. high, very leafy, glabrous; 

 leaves lanceolate or oblong-lanceolate, 3-5-nerved, 5-10 cm. long; heads solitary 

 or few together; involucres 15-20 mm. high; bracts glabrous, broadly lanceolate\ 

 acuminate; rays 12-15 mm. long; achenes glandular-puberulent. Aplopappus 

 Fremonti A. Gray. Plains and rocky hills: Kans. Colo. Submont. Je-S. 



