176 NORTH AMERICAN FLORA [Volume 34 



rent nearly to the base, their glands 5-9, in two rows; ligules 3 mm. long, 1-1.5 mm. wide; disk- 

 corollas 2.5 mm. long; tube very short; throat trumpet-shaped; lobes ovate; achenes 2-3 mm. 

 long, hispidulous on the angles; pappus 2-3 mm. long, of 10 lanceolate awn- tipped squamellae, 

 the inner 5 usually 3-awned, the outer ones with a single short awn or awn-tip. 



Type locality: "Border of western Texas and Mexico near El Paso" [but the type was 

 collected within Chihuahua]. 



Distribution: Texas to Nevada, Durango, and Coahuila. 



13. Thymophylla gracilis Rydberg, sp. nov. 



Hymenatherum Hartwegii A. Gray, PI. Wright. 1: 117, in part. 1852. 



Thymophylla Hartwegii Wooton & Standley, Contr. U. S. Nat. Herb. 16: 191, in part. 1913. 



A puberulent perennial, with a slender, suffruticose base; stems 1-2 dm. long, minutely 

 puberulent or glabrate, diffusely branched; leaves mostly opposite, 2-4 cm. long, pinnatifid, 

 with 3-7 slender, filiform, approximate, spinulose-tipped, puberulent divisions; peduncles 4-6 

 cm. long, slender; involucre turbinate-campanulate, 4-5 mm. high, 5-6 mm. broad, naked, 

 glabrous, except the ciliate margins of the outer series of bracts; bracts in two series of about 

 8 bracts each, united high up; inner bracts oblong, with triangular erose tips and 3-5 

 glands; outer bracts linear, with the ciliate free margins decurrent to near the base, their glands 

 5-7; ligules yellow, 3-4 mm. long, fully 1 mm. broad; disk-corollas about 3 mm. long; achenes 

 2.5 mm. long, glabrous; pappus distinctly double; inner 5 squamellae 2.5 mm. long, awned, 

 the outer 5 scarcely 0.5 mm. long, spatulate-oblong. 



Type collected at Barstow, Texas, July, 1901, David Griffiths 622 (herb. N. Y. Bot. Gard.). 

 Distribution: Texas to Arizona and Lower California. 



14. Thymophylla pentachaeta (DC.) Small, Fl. SE. U. S. 1295. 



1903. 



Hymenatherum pentachaelum DC. Prodr. 5: 642. 1836. 



Dyssodia pentachaeta B. L. Robinson, Proc. Am. Acad. 49: 507. 1913. 



A low puberulent perennial, suffruticose at the base, usually less than 1 dm. high; stems 

 with many short branches, rather densely pilose-puberulent; leaves mostly opposite, crowded, 

 1-2 cm. long, pilose-puberulent, pinnatifid, with 5-7 short, stiff, spinulose-tipped divisions; 

 peduncles 3-5 cm. long; involucre turbinate-campanulate, 4-5 mm. high and about as broad, 

 naked or with 1-3 minute subulate accessory bracts; principal bracts united high up, in two 

 series, the inner with triangular erose tips and 2-5 glands, the outer narrowly linear, with the 

 ciliate free margins decurrent to near the base; ligules 3 mm. long, 1.5 mm. wide; disk-corol- 

 las 2.5 mm. long; tube shorter than the trumpet-shaped throat; achenes nearly 3 mm. long, 

 glabrous; pappus double; inner 5 squamellae lanceolate, nearly 3 mm. long, including the awn, 

 the outer 5 oblong-spatulate, 1 mm. long. 



Type locality: Monterey, Nuevo Leon. 

 Distribution: Texas to Arizona and Nuevo Leon. 



15. Thymophylla myriophylla Rydberg, sp. nov. 



A puberulent perennial; stems 1-1.5 dm. high, diffusely branched, pilose-puberulent; 

 leaves opposite, spreading, crowded, 2-3 cm. long, puberulent, pinnatifid, with 7-11 very 

 slenderly filiform divisions; peduncles 5-7 cm. long, slender; involucre almost hemispheric, 

 5 mm. high, 7 mm. broad, with a few lance-subulate accessory bracts; principal bracts in two 

 series; inner bracts with broadly triangular erose tips and 1-3 rather inconspicuous glands; 

 outer bracts linear, oblong, ciliate, with the free margins decurrent to the base, the glands 

 3-5; ligules orange, 5 mm. long, 2 mm. wide; disk-corollas 3 mm. long; achenes 3 mm. long, 

 glabrous; pappus double; inner 5 squamellae lanceolate, erose, awn-tipped; outer 5 squamellae 

 oblanceolate or spatulate, obtuse or acute. 



Type collected at Laredo, Texas, March 21, 1903, J. Reverchon 3982 (herb. N. Y. Bot. Gard.). 



