894 CARDUACEAE 



barely mucronate; involucres 8-10 mm. broad; bracts with lanceolate, acute, 

 scarcely spreading tips; ligules about 6 mm. long. Aster parviflorus A. Gray. 

 Canons and arid places: N.M. s Utah Ariz. Son. Jl-Au. 



2. M. humilis (A. Gray) Standl. Annual; stem erect, 1-3 dm. high, 

 branched, glandular-puberulent; leaves once pinnatifid, glandular-puberulent; 

 divisions oblanceolate or oblong, entire or toothed, spinulose-tipped ; involucres 

 10-15 mm. broad; bracts linear, acute, glandular-puberulent; ligules rarely 1 cm. 

 long. A. canescens humilis A. Gray. Plains: N.M. Utah Ariz. Son. My-O. 



3. M. tanacetifolia (H.B.K.) Nees. Annual; stem branched, 1-4 dm. 

 high, green, glandular-puberulent and somewhat villous; leaves once or twice 

 pinnatifid, 1-4 cm. long, glandular-puberulent; divisions oblanceolate or linear, 

 entire or toothed; involucres hemispheric, fully 1 cm. high, 15-20 mm. broad; 

 bracts linear, attenuate, numerous; ligules 12-20 mm. long, blue-purple. A. 

 tanacetifolius H.B.K. M. coronopifolia (Nutt.) A. Nels. Sandy soil, plains, and 

 hills: Tex. S.D. Alta. Ariz.; Mex. Plain Submont. Je-O. 



4. M. Bigelovii (A. Gray) Greene. Biennial; stem glandular-hirsute, 3-10 

 dm. high, robust; leaves oblong or lanceolate, thin, coarsely dentate, glandular- 

 puberulent, the upper more or less clasping, the basal ones oblanceolate, petioled; 

 involucres about 15 mm. high, 2-3 cm. broad; bracts glandular-puberulent; 

 ligules about 1 cm. long. A. Bigelovii A. Gray. Plains and foothills: Colo. 

 N.M. Ariz. Submont. S-O. 



5. M. varians Greene. Biennial; stem erect, 6-10 dm. high, glandular-pu- 

 berulent above; leaves lanceolate, 7-10 cm. long, sessile, more or less spinulose- 

 serrate, glabrous or minutely puberulent; involucres hemispheric, 1 cm. high, 

 1.5-2 cm. broad; ligules 12-15 mm. long, purple. Plains and mountains: Colo. 

 N.M. Submont. Jl-S. 



6. M. aspera Greene. Biennial; stem stout, 6-10 dm. high, glandular-his- 

 pid; lower leaves oblanceolate, petioled, the upper oblong-lanceolate, sessile, 

 more or less clasping, spinulose-serrate, scabrous and glandular-pruinose ; invo- 

 lucres about 1 cm. high, 1.5 cm. broad; ligules 8-10 mm. long, purple. Moun- 

 tains: Colo. Submont. Mont. Je-Au. 



7. M. viscosula Rydb. Biennial, with a rosette of basal leaves; stems few, 

 about 2 dm. high, viscid-puberulent; basal leaves oblanceolate, petioled, the 

 upper similar or linear, but sessile, all saliently and coarsely toothed to nearly 

 entire; heads about 1 cm. high; ligules reddish purple, 8-10 mm. long and fully 

 1 mm. wide. M. viscosa Greene, not Dieteria viscosa Nutt. Plains and moun- 

 tains: Colo. Submont. Mont. Jl-Au. 



8. M. Pattersonii (A. Gray) Greene. Biennial, with a stout taproot; stem 

 1-2 dm. high, villous and glandular; basal leaves numerous, 4-6 cm. long, peti- 

 oled, spatulate, toothed above, glabrous or nearly so; involucres fully 1 cm. high 

 and nearly 2 cm. broad; bracts linear-attenuate, green except at the base, glandu- 

 lar-hispidulous; ligules 10-15 mm. long, purple. A. Pattersonii A. Gray. High 

 mountains: Colo. Mont. Alp. Jl-Au. 



9. M. sessiliflora (Nutt.) Greene. Biennial, leafy, 3-5 dm. high; leaves 

 linear, saliently toothed, 3-6 cm. long, scabrous-puberulent or nearly glabrous; 

 involucres about 1 cm. high and 1.5 cm. broad; bracts subulate, canescent; 

 ligules rose-purple. Hills and plains: Neb. Wyo. Plain. Au-S. 



10. M. rubricaulis Rydb. Biennial or perhaps perennial; stem erect or 

 nearly so, simple below, branched above, 4-6 dm. high, usually tinged with red 

 or purple; leaves entire or sparingly dentate, scabrous-ciliolate on the margins, 

 the largest 8 cm. long, and 8 mm. wide; involucre 10-12 mm. high, 12-15 mm. in 

 diameter; ligules numerous, dark blue, about 12 mm. long and 1 mm. wide. 

 Table-lands and hills: Colo. e Utah. Submont. Au-S. 



11. M. latifolia A. Nels. Biennial or perhaps perennial; stem erect, 1.5-2.5 

 dm. high; lower leaves petioled, the upper sessile; blades spatulate or oblanceo- 

 late, mostly 3-nerved, puberulent, or nearly glabrous above; inflorescence corym- 

 biform; involucres hemispheric, about 8 mm. high and 12 mm. broad; bracts 



