1486 CONTBIBUTIONS FROM THE NATIONAL HERBARIUM 



Chihuahua to Nuevo Le6n; Baja Cahfornia. Western North America-, 

 type from the plains of the Missouri. 



Suffrutescent or suffruticose, hirtellous-puberulent, bushy-branched, 40 cm. 

 high or less; leaves linear-filiform, 2 to 4 cm. long, 1 mm. (rarelj' 1.5 mm.) wide 

 or less, scaberulous; heads very numerous, corymbosely cymose-panicled, 4 to 6 

 mm. high, 2 to 3 mm. thick; phyllaries with narrow, often obscure, green tips. 

 "Hierba de San Nicolas" (Nuevo Le6n); "hierba de vibora," "coyaye" (New 

 Mexico). 



A decoction of the plant is reported to be used in New Mexico aa an emmen- 

 agogue and as a remedy for gastric disturbances. In the southwestern United 

 States this and related species are known variously as "yellow-weed," "brown- 

 weed," "sheep-weed," "broom-weed," and "snake-weed." The plants are 

 often very abundant upon the plains, and their abundance usually indicates 

 that the land has been over-grazed, especially by sheep. 

 7, Gutierrezia grandis Blake, Contr. U. S. Nat. Herb. 22: 592. pi. 55. 1924. 



Coahuila and Nuevo Le6n; type from Icamole, Nuevo Le6n. 



Suffruticose, 30 cm. high or more, strongly glutinous, scabridulous; leaves 

 chiefly linear-oblanceolate, 2.5 to 4.5 cm. long, 2 to 6 mm. wide, triplinerved; 

 heads turbinate or obovoid, larger than in any other of our species, scattered or 

 glomerate; rays 5 to 9; disk flowers 3 to 7. 



DOUBTFUL SPECIES. 

 GuTiERREZi.\ LiNEARiFOLi.\ Lag. Gen. & Sp. Nov. 30. 1816. This species, 

 the type of the genus, was originally ascribed to Mexico. The description does 

 not well agree with any Mexican species, however, and Gray identifies it with 

 much probability with the Chilean plant later described as Brachyrits paniculata 

 DC. 



24. APLOPAPPUS Cass. Diet. Sci. Nat. 56: 168. 1828. 



Herbs or shrul«, often glutinous; leaves alternate (in one species opposite), 

 linear-filiform to obovate, entire to pinnatifid or bipinnatifid; heads small or 

 medium, radiate or discoid, yellow, the rays and more rarely the disk sometimes 

 becoming purplish in age; involucre 2 to 7-seriate, scarcely or strongh^ graduated, 

 the phyllaries dry, usually thin-margined, sometimes with herbaceous tips, not 

 in distinct vertical ranks; achenes usually pubescent, slender, sometimes ribbed; 

 pappus of numerous often unequal bristles. 



Leaves all linear or linear-filiform, rarely spatulate-linear, entire, 3 mm. wide or 

 less. 

 Pappus bright white; heads solitary at tips of branchlets, radiate, compara- 

 tively large, the disk 1 cm. wide or more; involucre 7 to 13 mm. high, the 

 phyllaries lanceolate, scarcely graduated, with subherbaceous center and 

 tip. 

 Leaves 2 to 4 cm. long; ligules 1 to 2 cm. long; involucre 10 to 13 mm. high. 



1. A. linearifolius. 

 Leaves 1 to 2 cm. long; ligules 5 to 10 mm. long; involucre 7 to 10 mm. 



high la. A. linearifolius interior. 



Pappus brownish or dull whitish; heads mostly corymbose-panicled or 

 racemose-panicled, sometimes solitary, usually discoid, the disk 8 mm. 

 wide or less (in A. parrasanus becoming 11 to 12 mm. wide); involucre 

 8 mm. high or less, usually strongly graduated. 

 Heads solitary at tips of short leafy branchlets, these sometimes cymosely 

 arranged. 

 Leaves not punctate; young growth densely hirtellous 9. A. purpusii. 



