Genus 75.] 



THISTLE FAMILY. 



447 



75. POLYPTERIS Nutt. Gen. 2: 139. 18 18. 



Erect rough, glandular or cinereous, branching herbs, with alternate, mostly entire 

 leaves, or the lower opposite, and corymbose heads of tubular or both tubular and radiate 

 pink or purple flowers. Involucre campanulate or obconic, its bracts in 1 or 2 series, narrow, 

 herbaceous, nearly equal, or with a few exterior shorter ones, appressed, usually colored. 

 Receptacle small, flat, naked. Ray-flowers, when present, pistillate, fertile, the rays 3-cleft. 

 Disk-flowers perfect, fertile, their corollas with slender tubes and deeply 5-parted campanu- 

 late limbs. Anthers entire or emarginate at the base. Style-branches filiform, acutish, 

 glandular-pubescent throughout. Achenes linear or narrowly obpyramidal, quadrangular. 

 Pappus of S-12 lanceolate strongly costate scales, that of the outer achenes often much 

 shorter. [Greek, many-winged.] 



About 6 species, natives of the southern and south-central United States and Mexico. 

 Rays purple, deeply 3-lobed; leaves lanceolate. 1. P. Hookeriana. 



Rays none; leaves linear. 2. P. callosa. 



i. Polypteris Hookeriana (T. & G.) A. Gray. Hooker's Polypteris. 



(Fig. 3965.) 



Stevia sphacelata Nutt.; Torr. Ann. Lye. N. Y. 2: 214. 



Without description. 1827. 

 Palafoxia Hookeriana T. & G. Fl. N. A. 2: 368. 1842. 

 Polypteris Hookeriana A. Gray, Proc. Am. Acad. 19: 31. 



1883. 



Annual; stem rather stout, glandular-pubescent and. 

 viscid above, i-3 high. Leaves lanceolate, entire, 

 acute or acuminate, narrowed at the base, rough on^ 

 both sides, the upper alternate, the lower opposite 

 and slender-petioled, 2 / -4 / long, 3 // -5 " wide; bracts 

 of the involucre 10-16, linear-lanceolate or spatulate, 

 glandular-hispid, the inner with purplish tips; ray- 

 flowers 8-10; rays rose-purple, deeply 3-cleft, some- 

 times small, or none; achenes about A," long and y^" 

 thick; pappus-scales of the disk-flowers 6-S, lanceolate, 

 awned, more than half the length of the achene, those 

 of the ray-flowers as many, spatulate, obtuse, shorter. 



In dry soil, Nebraska to Texas and Mexico. July-Sept. 



2. Polypteris callosa (Nutt.) A. Gray. 

 Ray less Polypteris. (Fig. 3966.) 



Stevia callosa Nutt. Journ. Acad. Phila. 2: 121. 1821. 

 Polvpteris callosa A. Gray, Proc. Am. Acad. 19: 30. 



1883. 



Annual, glandular, at least above; stem slender, 

 paniculately branched, i-2 high. Leaves linear, 

 or linear-lanceolate, \'-2 l / 2 ' long, \ ,/ -2% // wide, 

 entire, short-petioled, mostly alternate; heads dis- 

 coid; bracts of the top-shaped involucre 8-10, 

 linear or narrowly oblong, herbaceous, pubescent, 

 about X / l n g; corollas purple, deeply 5-parted; 

 achenes narrowly obpyramidal, pubescent or gla- 

 brous, nearly as long as the involucre; pappus- 

 scales obovate or nearly orbicular, rounded, or 

 retuse, or sometimes minute, or none. 



In dry soil, Missouri to Texas and New Mexico. 

 June-Oct. 



76. BAH I A Lag. Gen. et Sp. Nov. 30. 1816. 

 Herbs or shrubs, more or less woolly, wtth opposite or alternate leaves, and small or 

 rather large, corymbose or solitary heads, of both tubular and radiate, yellow flowers. In- 

 volucre campanulate or hemispheric, its bracts in 1 or 2 series, herbaceous, obtuse, appressed, 

 nearly equal. Receptacle small, nearly flat, naked, foveolate. Ray-flowers in 1 series, pis- 

 tillate, Yertile. Disk-flowers perfect, fertile, their corollas with campanulate or cylindric, 



