STUDIES IN THE COMPOSITÆ. 291 
narrow and acutish in the inner, those of the male heads 
purplish at base, but mainly white, broadly and somewhat 
rhomboidly obovate, acute: pappus-bristles in the male 
dilated at summit and acute. 
A New-Mexican species, but only sparingly, and appar- 
ently not at all recently collected. I have seen it only in 
the U.S. Herbarium, where it exists under Fendler’s num- 
bers 521* and 528, and also in the Mexican Boundary Sur- 
vey collection, under n. 655. 
4. A New Genus of the Senecionidez. 
RAINIERA. 
Stoutish upright milky-juiced perennial, with the aspect 
and inflorescence of a Nabalus, but more nearly the char- 
acters of Mesadenia. Heads racemose, 2 or 3 in the axil of 
each small bract. Involucre simple, cylindrie, of 4 to 6 
firm erect bracts. Receptacle flat, naked, bearing 4 to 6 
tubular flowers; these with narrow cylindric proper tube 
rather shorter than the combined narrow throat and long 
linear segments. Achenes prismatic, glabrous, surmounted 
by a rather coarse pappus of firm sordid or brownish bristles 
which are smooth except at the slightly thickened and 
scabrous apex. 
R. srricta. Prenanthes stricta, Greene, Pitt. ii. 21 (1889). 
Luina Piperi, Robinson, Bot. Gaz. xvi. 43, t. 6 (1891). 
Psacalium strictum, Greene, Pitt. 1i., 228 (1892). Type more 
related to the Atlantic North American genus Mesadenia 
(which also is now known to have a milky juice) than to 
any other; but very distinct from it in characters of invo- 
lucre, receptacle, achenes and pappus. 
b. Some Western Species of ERIGERON. 
ERIGERON coRvMBOSUS, Nutt. Trans. Am. Phil. Soc. vii. 
308. The specimens labelled by this name in the various 
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