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NORTH AMERICAN FLORA 



[Volume 34 



Ligules 5-8, or rarely 9-10 mm. long, not conspicuously 

 veined; plant densely cespitose, forming large 

 cushions. 

 Involucre more than 1 cm. broad; scape 3-8 cm. long; 

 plant densely cespitose-pulvinate; leaves not con- 

 spicuously broad-based. 8. T. lanigera. 

 Involucre less than 1 cm. broad; scape 1—3 cm. (rarely 

 3-5 cm.) long; plant loosely cespitose; leaves con- 

 spicuously broad -based. 9. T. brevifolia. 

 Leaves glabrous or sparingly villous; scape finely pubescent or 

 villous (long-villous only in T. Torreyana) . 

 Branches of the caudex decidedly villous at the ends with 

 long, at first white, but later brownish hairs. 

 Pappus-scales lanceolate, not awned ; scape villous. 



Bracts linear-oblong; pappus-squamellae acuminate. 10. T. Torreyana. 

 Bracts elliptic-oblong; pappus-squamellae obtuse 



or acute. 11. T. herbacea. 



Pappus-scales oval, awned; scape silky. 



Bracts oval. 12. T. arizonica. 



Bracts linear-oblong. 13. T. Crandallii. 



Branches of the caudex not conspicuously villous. 



Bases of the leaves not wider than the oblanceolate 

 or almost linear blades; branches of the caudex 

 short and stout. 

 Leaves glabrous, scarcely punctate; bracts slightly 



shorter than the disk; ligules not strongly nerved. 14. T. e punctata. 

 Leaves long-hairy, distinctly punctate; bracts three- 

 fourths as long as the disk; ligules strongly nerved. 15. T. anguslifelia. 

 Bases of the leaves 2-4 times as wide as the linear leaf- 

 blades; branches of the caudex or rootstock elon- 

 gate. 

 Perennial with a caudex; squamellae lanceolate, 

 acuminate. 

 Caudex branched underground, with erect 



branches. 16. T. fastigiata. 



Caudex with scaly, ascending or decumbent, 



above-ground branches. 17. T. linearis. 



Perennial with a slender rootstock; squamellae 



ovate, awn-tipped. 18. T. angustata. 



Stems 2-3 dm. high, with 2-6 stem-leaves. 



Plant appressed-silky, silvery. 19. T. argentea. 



Plant green, loosely pilose. 



Stem-leaves narrowly oblanceolate; basal leaves oblanceolate; 



caudex without hair-tufts. 20. T. fortnosa. 



Stem -leaves linear or narrowly linear-oblanceolate ; caudex 

 conspicuously hair-tufted. 

 Basal leaves oblanceolate to linear-oblanceolate, more than 



5 mm. wide; involucre hemispheric. 21. T. leptoclada. 



Basal leaves narrowly linear-oblanceolate, less than 5 mm. 



wide; involucre narrower. 22. T. Iveadana. 



Annuals or biennials (or sometimes perennials?), with a tap-root. 

 Plants branching near the base, the basal leaves not rosulate. 



Leaves linear or nearly so; stem sparingly hairy, branched through- 

 out; involucre 5-7 mm. broad; awn-tips as long as the squamellae. 23. T. linearifolia. 

 Leaves, at least the lower ones, oblanceolate or spatulate; stem 

 branched above; involucre fully 1 cm. broad; pappus-awns shorter 

 than the squamellae. 24. T. latior. 



Plants with a distinct basal rosette of villous oblanceolate leaves; 

 stem branched some distance up; stem -leaves linear; involucre 

 1 cm. broad. 

 Basal leaves broadly oblanceolate, entire. 25. T. oblongi folia. 



Basal leaves narrowly oblanceolate, some of them lobed. 26. T. Dodgei. 



1. Tetraneuris depressa (T. & G.) Greene, Pittonia 3: 266. 1898. 



Aclinella depressa T. & G.; A. Gray, Mem. Am. Acad. II. 4: 100. 1849. 



A densely pulvinate acaulescent perennial the branches of the caudex densely covered 

 with long brown hairs; leaves densely clustered, linear, 1-2 cni. long, 1-2 mm. wide, glabrate, 

 conspicuously punctate; heads sessile among the leaves; involucre 1 cm. broad or less; ligules 

 6-7 mm. long; disk-corollas 3 mm. long; achenes densely hirsute, 2 mm. long; squamellae ovate, 

 tapering into an awn, including the awn 3 mm. long. 



Type locality: Rocky Mountains, the locality unknown [probably Utah]. 

 Distribution: Utah. 



