Genvs 77.] 



THISTLE FAMILY. 



449 



2. Picradenia scaposa (DC.) 



Britton. Dotted Picradenia. 



(Fig. 3969.) 



Cephalophora scaposa DC. Prodr. 5: 663. 1836. 

 Aclinella scaposa Xutt. Trans, Am. Phil. Soc. 

 (II.) 7: 379. 1841. 



Perennial by thick roots .ind a slender 

 branching caudex; scapes tufted, slender, 

 monocephalous, pubescent or glabrate, some- 

 times woolly below, 6'-i5' high. Leaves all 

 basal, or near the base, linear or narrowly 

 spatulate, entire (rarely somewhat cleft), 

 glabrous, or slightly villous, conspicuously 

 punctate, \'-2\'z' long, i"-2^" wide; heads 

 I'-Iji' broad; involucre nearly hemispheric, 

 its bracts often obtuse, densely tomentose; 

 rays 12-20; pappus of about 5 ovate or oblong 

 awned scales. 



In dry soil, Nebraska to Texas, Mexico and 

 New Mexico. May-Nov. 



3. Picradenia acaiilis (Nutt.) Britton. 

 Stemless Picradenia. (Fig- 3970.) 



Aclinella acaulis Nutt. Gen. 2: 173. 1818. 



Similar to the preceding species,perennial from 

 thick roots and a stout branched caudex; scapes 

 tufted, rather stout, or slender, densely silky 

 or tomentose, ■2'-'$,' high. Leaves all borne on 

 the ends of the branches of the caudex, spatu- 

 late, entire, obtuse or obtusish, I'-i' long, I'/i"- 

 3" wide, densely silky or villous; heads 9"-i8" 

 broad; involucre hemispheric, its bracts densely 

 villous; rays 10-15; pappus of 5 or 6, ovate or 

 oblong, awned scales. 



In dry or rocky soil, Northwest Territory to Mon- 

 tana, Nebraska, Arizona and New Mexico. May- 

 Aug. 



4. Picradenia odorata (DC.) Britton. 



Fragrant Picradenia. Limonillo. 



(Fig. 3971.) 



Hymenoxys odotala DC. Prodr. 5: 661. 1836. 

 Aclinella odorata A. Gray, Mem. .\m. Acad. (II.) 4: 

 loi. 1849. 



Annual; stem much branched, puberulent, spar- 

 ingly hirsute or glabrous, i°-2° high, leafy. Leaves 

 i'-2' long, 1-3-parted into filiform entire somewhat 

 pubescent segments about Yz" wide; heads com- 

 monly numerous, ()"-io" broad; involucre cam- 

 panulate, puberulent, its outer bracts 6-9, lanceo- 

 late, keeled, acute, united at the base; rays 7-10, 

 cuneate; pappus-scales lanceolate, acuminate. 



In dry soil, Kansas to Texas, Mexico and southern California. .A.pril-July. 



29 



