COMPOSITAE (COMPOSITE FAMILY) 549 



64. HELIANTHELLA T. & G. 



Perennial herbs with mostly simple stems, entire, scattered, and sessile 

 leaves, and solitary heads with yellow ray and yellow or purplish-brown disk- 

 flowers. Heads many-flowered, the ray-flowers neutral; those of the disk 

 perfect. Bracts of the involucre in about 2 series, loose, somewhat foliaceous. 

 Chaff of the receptacle persistent, embracing the achenes. Corolla of the disk 

 cylindrical, elongated, 5-toothed, with a very short proper tube. Branches of 

 the style very hispid, more or less obtuse. Achenes compressed, with one or 

 both margins slightly winged and produced at the summit into short auricu- 

 late and lacerate-persistent appendages or into an awn, sometimes with inter- 

 mediate squamellae. 



Disk yellowish; the anthers dark. 



Heads large; disk 2-3 cm. broad; rays 3-4 cm. long . . . 1. H. quinquenervis. 



Heads half as large 2. H. Parryi. 



Disk purple. 



Heads several, small; rays 5-6 mm. long . . . . . 3. H. microcephala. 



Heads solitary or few, larger; rays 20-25 mm. long . . . 4. H. uniflora. 



1. HeHanthella quinquenervis (Hook.) Gray, Proc. Am. Acad. 19: 10. 1883. 

 Somewhat hirsutely pubescent or almost glabrous; stems solitary or scat- 

 tered, 6-12 dm. high: leaves mostly opposite, oblong- or ovate-lanceolate, 

 acuminate, 1-2, dm. long, uppermost sessile; the lower ones tapering into mar- 

 gined petioles, and the lowest (2-3 dm. long) into longer petioles: head mostly 

 long-ped uncled, ample, the disk 2-3 cm. in diameter: rays 15-20, pale yellow, 

 commonly 3-4 cm. long: pappus of 2 slender awns, half the length of the 

 achene, and nearly thrice the length of the squamellae, which form a con- 

 spicuous, finely dissected fringe. Mountains; from Dakota and Montana to 

 southern Colorado. 



2. Helianthella Parryi Gray, Proc. Acad. Phila. 68. 1863. Hispidulous- 

 hirsute; stems numerous from a thickened root, 3-4 dm. high, rather slender: 

 leaves mostly alternate, more rigid, lanceolate and 3-6 cm. long, or the 

 lowest and radical oblong-spatulate and double the size: heads and rays 

 barely half the size of the preceding: pappus of fimbriately dissected squamel- 

 lae only, or with a pair of slender awns not surpassing them. Mountains of 

 Colorado and New Mexico. 



3. Helianthella microcephala Gray, Proc. Am. Acad. 19: 10. 1883. His- 

 pidulous-scabrous; stems numerous from a greatly thickened root, 2-3 dm. 

 high, slender, somewhat paniculately or corymbosely branched at summit and 

 bearing several heads: leaves rigid, all but the lower alternate; the radical 

 lanceolate-spatulate : the upper cauline nearly linear and sessile, 2-3 cm. long: 

 involucral bracts linear-oblong, mostly obtuse: rays not over 6 mm. long: 

 pappus of several slender squamellae intermixed with the long hairs, 2 mar- 

 ginal ones often extended and awn-like. Borders of Colorado and adjacent 

 New Mexico and Utah. 



4. Helianthella uniflora (Nutt.) T. & G. ex Gray, 1. c. Minutely pubescent 

 or glabrate; stems 3-6 dm. high: leaves more commonly opposite, sometimes 

 all alternate, oblong-lanceolate, 5-12 cm. long; the lower short-petioled : invo- 

 lucre pubescent or slightly hirsute: rays 25-30 mm. long: chaffy bracts of the 

 receptacle firm-chartaceous: achenes more or less ciliate; pappus a pair of long 

 awns and rather conspicuous squamellae. (H. multicaulis Eat. Bot. King's 

 Exp.) Mountains of Montana and eastern Idaho to southern Utah. 



55. XIMENESIA Cav. 



Annual caulescent herbs, with pubescent foliage. Leaves alternate or 

 sometimes opposite, simple, toothed or somewhat laciniate. Heads solitary 

 or few, radiate, showy, peduncled. Receptacle convex, chaffy. Ray-flowers 

 pistillate, numerous, yellow; disk-flowers numerous, perfect. Stigmas with 

 slender pubescent appendages. Achenes flat, winged. Pappus of short and 

 straight awns. 



