178 NORTH AMERICAN FLORA [Volume 34 



20. Thymophylla canescens Rydberg, sp. nov. 



A depressed perennial, suffruticose at the base; stems less than 1 dm. high, diffusely 

 branched, densely puberulent; leaves crowded, canescent-pilose, mostly opposite, crowded, 

 pinnatifid, with 5-9 filiform, spinulose-tipped, rather stiff segments; peduncles 3-4 cm. long; 

 involucre hemispheric, 3.5-4 mm. high, 7-8 mm. broad, puberulent, not ciliate; bracts in two 

 series, with membranous margins and 1-3 glands; ligules 4 mm. long, 1.5 mm. wide; disk- 

 corollas 2.5 mm. long; achenes 2 mm. long, hirsutulous; pappus double; inner 5 squamellae 

 lanceolate, 3 mm. long, awn-tipped, the outer 5 less than 1 mm. long, oblong. 



Type collected at San Luis Potosi, 1878, Parry &° Palmer 515 (herb. Columbia Univ.). 

 Distribution: Coahuila, Nuevo Leon, and San Luis Potosi. 



21. Thymophylla setifolia Lag. Gen. & Sp. Nov. 25. 1816. 



Hymenalherum setifolium A. Gray, Proc. Am. Acad. 19: 42. 1883. 

 Hymenalherum setifolium radiatum Brand. Univ. Calif. Publ. Bot. 4: 279. 1912. 

 Dyssodia setifolia B. L. Robinson, Proc. Am. Acad. 49: 508. 1913. 



A cespitose perennial, suffruticose below; stems 1-2 dm. high, densely white-tomentose, 

 much branched; leaves mostly opposite, crowded, with smaller ones fascicled in their axils, 

 tomentose, 1-3 cm. long, pinnatifid into 3-7 filiform, spinulose-tipped segments; peduncles 

 4-6 cm. long; involucre tomentose, turbinate, 4 mm. high, 5-6 mm. broad; bracts united very 

 high up, with lanceolate, acuminate tips, bearing 1-3 glands; ray-flowers usually wanting, 

 rarely present; ligules 3 mm. long, 1 mm. wide; disk-corollas 2 mm. long; tube shorter than 

 the narrowly funnelform throat; achenes 2.5 mm. long, glabrous; pappus of 5-10 squamellae, 

 either all oblong, about 0.5 mm. long, muticous and erose, or the inner lanceolate, awn- 

 tipped and nearly 2 mm. long. 



Type locality: "Nova Hispania" [Mexico]. 

 Distribution: Coahuila to Queretaro and Aguas Calientes. 



22. Thymophylla Greggii A. Gray, Mem. Am. Acad. II: 4: 92. 



1849. 



Thymophylla Greggii radiata A. Gray, PI. Wright. 1: 119. 1852. 

 Hymenatherum Greggii A. Gray, Proc. Am. Acad. 19: 42. 1883. 

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



A perennial, with a cespitose suffrutescent base; stems 1-2 dm. high, densely white-tomen- 

 tose, diffusely branched ; leaves opposite, crowded, tomentose, with smaller fasciculate ones in 

 their axils, 1-1.5 cm. long, mostly 3-cleft into rather stiff, spinulose-tipped, filiform segments; 

 peduncles 4-6 cm. long; involucre campanulate, 4 mm. high and about as broad, tomentose 

 when young, often glabrate in age; bracts with deltoid or lanceolate tips, bearing 1-3 glands; 

 ray-flowers usually present; ligules 3 mm. long, 1-1.5 mm. wide; disk-corollas 2.5 mm. long; 

 tube half as long as the trumpet-shaped throat; achenes 2.5 mm. long, glabrous; pappus a 

 crown of wholly united rather firm squamellae, sinuately dentate at the apex. 



Type locality: Buena Vista, Coahuila. 



Distribution: Western Texas, New Mexico, and Coahuila. 



Illustration: A. Gray, PI. Wright, pi. 7 . 



15. GNAPHALIOPSIS DC. Prodr. 7: 258. 1838. 



Cespitose, floccose perennials with a woody base. Leaves mostly alternate, entire, 

 densely floccose. Heads radiate, sessile at the ends of the blanches. Involucre campanu- 

 late, densely floccose, without calyculum; bracts in a single series, united to near the apex. 

 Receptacle naked, convex. Ray-flowers few, pistillate and fertile; ligules oblong, yellow. 

 Disk-flowers many, hermaphrodite and fertile; corollas glabrous; tube shorter than the 

 trumpet-shaped throat. Anthers obtuse. Style-branches with subcapitate truncate tips. 

 Achenes elongate-clavate, angled. Pappus double; inner 5 squamellae lanceolate, awn-tipped, 

 equaling the disk-corollas; outer 5 squamellae much shorter and obtuse. 



Type species, Gnaphaliopsis micropoides DC. 



