THISTLE FAMILY 865 



21. MACRONEMA Nutt. 



Undershrubs, never resinous-punctate, with short branches, leafy up to the 

 heads. Involucre campanulate; its bracts imbricate, in a few series of more or 

 less unequal length, linear or lanceolate, the inner thin, chartaceous or somewhat 

 scarious, the outer more or less foliaceous and passing into the leaves. Recep- 

 tacle naked, alveolar. Ray-flowers, when present, ligulate, pistillate and fertile; 

 ligules yellow, conspicuous. Disk-flowers perfect; corollas tubular-trumpet 

 shaped, 5-lobed. Anthers obtuse at the base. Branches of the style stigmatic 

 their whole length, with very long and attenuate-filiform appendages. Achenes 

 slender, compressed, 5-nerved, soft-pubescent. Pappus of numerous white soft 

 bristles. 



Heads radiate; branches glandular, not tomentose. 



Heads small, fastigiate-clusfcered ; disk 5-8 ram. in diameter. 



Leaves broadly obovate, mucronate-cuspidate. 1. M. obovatum. 



Leaves oblanceolate, acute or pointed. 2. M. Watsoni. 

 Heads larger, solitary; disk 1 cm. or more in diameter. 



Leaves oblanceolate, acute. 3. M. suflruticosum. 



Leaves spatulate, obtuse or mucronate. 4. M. grindeli folium. 

 Heads discoid ; branches white-tomentose. / 



Leavas oblong-oblanceolate. 



Outer bracts linear to oblong, acute. 5. M. discoideum. 



Outer bracts broadly oblong, obtuse or mucronate. 6. M . obtusum. 



Leaves linear. 7. M. lineare. 



1. M. obovatum Rydb. Glandular-puberulent undershrub, 2-3 dm. high; 

 leaves 1-2 cm. long, 7-10 mm. wide; heads usually 2-3 together, about 10 mm. 

 high; bracts firm, oblong-linear, abruptly acute, unequal, imbricate in about 

 4 series; ligules about 10, short, 4-5 mm. long. Canons and hillsides: Utah. 

 Submont. Je-Au. 



2. M. Watsoni (A. Gray) Greene. Glandular undershrub, 1-3 dm. high; 

 leaves thin, 1-2 cm. long; heads fastigiate-clustered, about 10 mm. high; bracts 

 linear-lanceolate, attenuate, the outer 1 or 2, foliaceous; ligules 6-8 mm. long. 

 Aplopappus Watsoni A. Gray. Mountains : Nev. Utah Ariz. Submont. Au-S. 



3. M. suffruticosum Nutt. Undershrub, 1-2 dm. high; branches brown; 

 leaves 2-3 cm. long, glandular-hirsute; heads solitary, 10-12 mm. high; bracts 

 linear-lanceolate, acuminate or the outer foliaceous and attenuate; ligules 8-10 

 mm. long. A. suffruticosus A. Gray. Hills: Mont. Wyo. Ariz. Calif. Sub- 

 mont. Mont. Jl-S. 



4. M. grindelifolium Rydb. Much branched undershrub, 1-2 dm. high; 

 branches gland ular-puberulent; leaves 1-2 cm. long, glandular-pubescent; mar- 

 gins more or less crisped; heads 1.5 cm. high; bracts few, linear-lanceolate or 

 acute; ligules 6-12, conspicuous, often 1 cm. long. M. grindelioides Coult. & 

 Nels. High mountains: Mont. Wyo. Ida. Ore. Submont. Mont. Jl-S. 



5. M. discoideum Nutt. Low branched undershrub, 1-2 dm. high; leaves 

 oblong to oblanceolate, 1-3 cm. long, glandular-puberulent; heads solitary, about 

 1.5 cm. high and broad; inner bracts few, linear-lanceolate, attenuate. A. Mac- 

 ronema A. Gray. Mountains: Colo. Calif Ore. Submont. Alp. Jl-Au. 



6. M. obtusum Rydb. Dense glandular-pubescent undershrub, 2-4 dm. 

 high; leaves oblong-oblanceolate, about 3 cm. long, obtuse or mucronate; heads 

 about 18 mm. high, 10-18 mm. in diameter; inner bracts acute, scarcely more 

 than half as long as the flowers. Mountains: Colo. Mont. Jl. 



7. M. lineare Rydb. Low undershrub, woody only at the base, 1-2 dm. 

 high; leaves numerous, linear, acute, glandular-puberulent, sometimes also more 

 ar less tomentose; heads 1-1.5 cm. high; bracts few, linear, acuminate, the outer 

 foliaceous. Sandy or gravelly places: Wyo. Submont. Au. 



22. STENOTUS Nutt. 



Low perennials, with cespitose woody caudices and narrow, entire, more or 

 less coriaceous and evergreen (except in the last species), mostly basal leaves. 

 Involucre hemispherical or nearly so; its bracts imbricated in a few rows, ap- 



