1008 FLORA. 



present, pistillate, fertile, the rays 3 -cleft. Disk-flowers perfect, fertile, thei* 

 corollas with slender tubes and deeply 5-parted campanulate limbs. Style- branches 

 filiform, acutish, glandular-pubescent throughout. Achenes linear or obpyramidal, 

 quadrangular. Pappus of 8-12 lanceolate strongly costate scales, that of the outer 

 achenes often much shorter than that of the inner. [Greek, many- winged.] About 

 6 species, natives of the southern and south-central U. S. and Mex. 



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



Rays none ; leaves linear or linear-lanceolate. 2. /* callosa. 



1. Polypteris Hookeriana (T. & G.) A. Gray. HOOKER'S POLYPTERIS. 

 (I. F. f. 3965.) Annual; stem rather stout, glandular-pubescent and viscid above, 

 3-9 dm. high. Leaves lanceolate, entire, acute or acuminate, narrowed at the base, 

 rough on both sides, the upper alternate, the lower opposite and slender-petioled, 

 tj-io cm. long, 6-IO mm. wide; bracts of the involucre 10 16, linear- lanceolate or 

 spatulate, glandular-hispid, the inner with purplish tips; ray-flowers 8-10; achenes 

 about 8 mm. long and I mm. thick; pappus-scales of the disk-flowers 6-8, lanceo- 

 late, awned, those of the ray-flowers as many, spatulate, obtuse, shorter. In dry 

 soil,' Neb. to Tex. and Mex. July-Sept. 



2. Polypteris callosa (Nutt.) A. Gray. RAYLESS POLYPTERIS. (I. F. 

 f. 3966.) Annual; glandular, at least above; stem slender, paniculately branched, 

 3-6 dm. high. Leaves 3-6 cm. long, 2-5 mm. wide, entire, short-petioled, mostly 

 alternate; bracts of the top-shaped involucre 8-10, linear or narrowly oblong, her- 

 baceous, pubescent, about 6 mm. long; corollas purple, deeply 5-parted; achenes 

 narrowly obpyramidal, pubescent or glabrous, nearly as long as the involucre; 

 pappus-scales obovate or nearly orbicular, rounded or retuse, or sometimes minute, 

 or none. In dry soil, Mo. to Tex. and N. Mex. June- Oct. 



76. PICRADENIOPSIS Rydb. 

 [BAHIA Nutt., not Lag.] 



Herbs or shrubs, more or less woolly, with opposite or alternate leaves, and 

 small or rather large corymbose or solitary heads, of both tubular and radiate 

 yellow flowers. Involucre campanulate or hemispheric, its bracts in I or 2 series 

 herbaceous, obtuse, appressed, nearly equal. Receptacle small, nearly flat, naked, 

 foveolate. Ray-flowers in I series, pistillate, fertile. Disk-flowers perfect, fertile, 

 their corollas with campanulate or cylindric 5 -cleft limb. Anthers entire or emar- 

 ginate at the base. Style-tips mostly truncate and obtuse. Achenes quadrangu- 

 lar; linear or oblong. Pappus of several nerveless or costate scales, rarely none. 

 [Name referring to resemblance of this genus to Picradenia.~\ 



i. Picradeniopsis oppositifolia (Nutt.) Rydb. FALSE BAHIA. (I. F. f. 3967.) 

 Perennial, herbaceous; stem densely cinereous, much branched, 1-3 dm. high, very 

 leafy. Leaves opposite, or the uppermost alternate, 1-4 cm. long, palmately 2-5- 

 parted into linear, obtuse or obtusish, entire segments, finely cinereous on both 

 sides; heads short-peduncled, 12-18 mm. broad; involucre campanulate, or becom- 

 ing hemispheric, its bracts oblong, obtuse, densely tomentose; rays 5-7, short; 

 achenes linear-oblong, glandular-pubescent; pappus of 4-8 spatulate to lanceolate 

 scales with thickened bases. On plains, S. Dak., Neb. and Mont, to Kans. and 

 N. Mex. June-Sept. [Bahia oppositifolia Nutt.] 



77. TETRANEURIS Greene. 



Branched or scapose, villous-pubescent or glabrous, bitter and aromatic herbs, 

 with alternate or basal, often punctate entire leaves, and small or rather large, 

 peduncled heads of both tubular and radiate yellow flowers, or rays rarely want- 

 ing. Involucre hemispheric, campanulate or depressed, its bracts imbricated in 

 2-3 series, appressed. Receptacle convex or conic, naked. Ray-flowers pistillate 

 and fertile, the rays 3-toothed, 3-lobed. Disk-flowers perfect, fertile, their corollas 

 with 4-5-toothed limbs. Anthers entire or minutely sagittate at the base. Style- 

 branches truncate and penicillate at the summit. Achenes turbinate, 5-io-ribbed 

 or angled, villous or pubescent. Pappus of 5-12 thin aristate acuminate or trun- 

 cate scales. [Greek, four- nerved.] About 20 species, natives of western N. Am. 

 and Mex. Besides the following, some 10 others occur in the western U. S, 



