Part 1. 1914] CARDUACEAE: HELENIEAE 9 



10. Psilostrophe Cooperi (A. Gray) Greene, Pittonia 2: 176. 1891. 



Riddellia Cooperi A. Gray, Proc. Am. Acad. 7: 358. 1868. 



A perennial, shrubby at the base; stems in clumps, branched, 3-5 dm. high, densely white- 



pannose when young; leaves narrowly linear, 3-7 cm. long, 1-2 mm. broad, or the lower ones 



broader, green and glabrate in age; heads scattered; peduncles 3-8 cm. long; involucre cam- 



panulate, about 8 mm. long, 5 mm. broad; bracts 15-20, oblong; ligules 4 or 5, rarely 6-8, 



broadly oval, 10-12 mm. long and nearly as wide, broadly 3-toothed; disk-corollas slightly 



glandular-granulif erous ; achenes glabrous ; squamellae oblong or lanceolate, entire or arose. 



Tvpiv locality: Fort Mojave. 



Distribution: Southern California, Nevada, Utah, Arizona, and Lower California. 



9. BAILEYA Harv. & Gray; Torr. in Emory, Notes Mil. 

 Rec. 144. 1,848. 



Annual or perennial floccose herbs. Leaves alternate, once or twice pinnatifid or the 

 upper entire. Heads radiate, several- or many-flowered, on long peduncles. ^Involucre 

 hemispheric, of many nearly equal herbaceous woolly bracts in two series. Receptacle flat 

 or convex, naked, alveolate. Ray-flowers 5-50, in a single series, pistillate, fertile; ligules oval 

 or oblong, broadly 3-toothed at the apex, 7-nerved, becoming scarious-papery, persistent. 

 Disk-flowers many, hermaphrodite, fertile; corolla-tube short; throat tubular-funnelform ; limb 

 5-toothed; teeth glandular-bearded. Anthers linear, minutely sagittate at the base. Style- 

 branches short, with truncate-capitate ends. Achenes oblong-linear, truncate at the apex, 

 somewhat angled, many-ribbed or many-striate, those of the rays callous-thickened at the 

 apex. Pappus none. 



Type species, Baileya muUiradiata Harv. & Gray. 



Ray-flowers 5-6, indistinctly 3-toothed; slender, annual. 1. B. pauciradiala. 



Ray-flowers 20-50, distinctly 3-toothed. 



Ligules 8-12 mm. long, oblong or cuneate-oblong; intermediate ribs of the 



achenes rather prominent, although often not so strong as those of the 



angles. 



Stem erect, branched, leafy for more than half its height; peduncles 



5-10 cm. long. 



Annual; stem erect, branched; branches ascending; ligules 8-9 mm. 



long; leaf-segments linear or oblong. 2. B. pleniradiala. 



Perennial or biennial. 



Leaf -segments obovate, short ; stem branched above with ascend- 

 ing branches; achenes with the principal ribs slightly stronger 

 than the intermediate ones; ligules about 8 mm., long. 3. B. Thiirberi. 



Leaf -segments linear, oblong, or lanceolate; stem branched at 

 the base with erect branches; achenes with the principal ribs 

 much stronger; ligules 10-12 mm. long. 4. B. perennis. 



Stem decumbent and branched at base; leaves numerous, clustered at 

 the base or on the lower half of the stem; peduncles 1-2 dm. long; 



leaf-segments broad, obovate. 5. B. muUiradiata. 



Ligules about 15 mm. long, linear; intermediate ribs of the achenes obsolete. 6. B. aiislralis. 



1. Baileya pauciradiata Harv. & Gray; A. Gray, Mem. Am. Acad. II. 



4: 105. 1849. 



A floccose annual; stem 2-3 dm. high, loosely and densely villous, with ascending branches; 

 lower leaves oblanceolate in outline, 5-10 cm. long, densely villous, more or less pinnatifid with 

 linear or oblong divisions; upper leaves usually entire and linear; heads corymbiform-cymose; 

 peduncles 2-5 cm. long; involucre about 6 mm. high; bracts 8-10; ligules 5-6, oval, truncate, 

 rather indistinctly 3-toothed, 6-8 mm. long, 5-6 mm. broad; disk-flowers 10-20; corollas 3 mm. 

 long, glandular-granuliferous ; achenes about 5 mm. long, linear, slightly clavate, truncate at 

 the apex, indistinctly angled and striate-ribbed, scabrous-hispidulous and somewhat glandular- 

 granuliferous. 



Type locality: California. 



Distribution: Southern California, adjacent Arizona and Sonora, and Lower California. 



