Moist ground, wet meadows, seepage areas and along streams, in N.M. (Colfax, 

 Otero and Union cos.) and Ariz. (Apache, Coconino, Cochise and Pima cos.), 

 July-Oct.; s.e. Ida., s. through Colo., N.M., Ariz, into Chih. 



13. Bidens Bigelovn Gray. Fig. 772. 



Annual herb, erect, almost glabrous, 4-10 dm. tall; leaves petiolate (petioles 

 10-25 mm. long), including the petiole to 8 cm. long, tripartite, the segments 

 3- to 5-partite, their lobes oblong or cuneate and pinnatifidly incised (with the 

 rather few teeth mucronate), membranous, more or less ciliate; peduncles to 

 15 cm. long; heads subsolitary, at anthesis about 6-9 mm. broad and equally tall; 

 involucre basally hispid; outer phyllaries 6 to 9, linear, dorsally glabrous, mar- 

 ginally ciliate, terminally sharp-apiculate, 5-7.5 mm. long; inner phyllaries 

 lanceolate, often shorter; rays absent or 3 to 5 in number, whitish, 5-7 mm. 

 long, oblong-obovate; achenes subquadrangulate, dimorphic, the 1 to 4 exterior 

 ones linear-cuneate, truncate, papillose-hispidulous and very scabrous, often cas- 

 taneous, the body 5-7 mm. long, the apex either essentially awnless or with 2 or 3 

 short retrorsely barbed pappus awns; inner achenes narrowly linear, black, glabrate 

 below but commonly erect-hispid above, the body 8-12 mm. long; pappus awns 

 2 or 3, retrorsely barbed, 1.5-3 mm. long. 



Rather frequent in moist canyons, on wet stream banks and wet shady places 

 in the Tex. Trans-Pecos mts., N.M. (Dona Ana, Grant, Sierra and Socorro cos.) 

 and Ariz. (Apache, Greenlee, Gila, Cochise and Santa Cruz cos.), summer; Colo., 

 N.M., Tex., Ariz, and Son. 



14. Bidens bipinnata L. Spanish needles. Fig. 773. 



Annual herb, erect, commonly glabrous but rarely minutely setose-hispid, 

 branched, 3-12 (-17) dm. tall; leaves petiolate (petioles 2-5 cm. long), including 

 the petioles 4-20 cm. long, normally 2- or 3-pinnate, membranous, ciliate, the 

 ultimate segments often deltoid- (or rhombic-) lanceolate, toward the base 

 cuneate; peduncles to 1 dm. long; heads 5-7 mm. high, 4-6 mm. broad; involucre 

 pubescent at base; outer phyllaries 7 to 10, linear, apically acute (var. bipinnata) 

 or distally dilate (var. biternatoides Sherff), 3-5 mm. long; inner phyllaries linear- 

 lanceolate, half again as long; rays inconspicuous, yellowish-white, not exceeding 

 the disk florets, lanceolate or obovate-lanceolate, apically entire or 2- or 3-lobulate; 

 achenes linear, tetragonal, the body commonly black, distally attenuated and often 

 sparsely setulose, glabrate below, 10-18 mm. long (the outer shorter and often 

 castaneous); pappus awns usually 3 or 4, yellowish, retrorsely barbed, 2-4 mm. 

 long. 



In rich alluvial soils and other wet places in Okla. (Dewey and Ottawa cos.) 

 and e. Tex., rare (var. biternatoides) in moist canyons of Trans-Pecos mts. and 

 N.M. (Dona Ana Co.) and Ariz. (Greenlee, Cochise and Santa Cruz cos.), summer; 

 most of e. U.S.; Mex.; Braz., Arg., Chile, etc.; widely adv. in Old World. 



35. Cosmos Cav. Cosmos 

 A genus of perhaps 50 species of the warmer parts of America. 

 1. Cosmos parviflorus (Jacq.) Pers. 



Annual herb, erect, slender, often branched above, 3-9 dm. tall; leaves 

 scarcely petioled or with petioles wing-margined and to about 5 mm. long, with 

 total length of about 3-7 cm., bipinnate; segments very narrowly linear, only 

 0.1-0.6 mm. broad, glabrous above and below, often strongly spinulose-ciliate, 

 apically acute or subobtuse, the rachis and its branches somewhat winged; heads 

 singly terminating peduncles 1-3 dm. long, 15-25 mm. broad, 6-9 mm. high; 

 outer phyllaries commonly 8, lance-acuminate or linear-elongate, often spreading 

 or even reflexed, on the outer surface green and marked with 3 to 5 black nerves, 



1672 



