174 COMPOSITE. Erigeron. 



y. pubescens (Hook. ! 1. c.) : stem and leaves hirsute throughout with a 

 spreading pubescence. o /-i • 



Prairies and open plains, Missouri, Nuttall! Mr. Nicollet! S^v. St. Croix 

 River, Dr. Houghton ! Saskatchawan, Drmmnond! and throughout the 

 woody country to lat. 64°, Richardson! Also in Oregon near the Rocky 

 Mountains, Nuttall! ^r. and on Lewis River, Mr. Tolmie! i3. Missouri, 

 Nuttall ! to Arctic America, Rkhanhon ! y. Prairies in the Rocky Moun- 

 tains (lat. 52°), Drummond! July-Aug.— Stems 10 inches to 2 feet high, 

 often several from the same root ; the lower portion, as well as the radical 

 leaves often entirely glabrous : the upper cauline leaves usually small arid 

 scattered, lanceolate or nearly linear, pointed. Heads about as large as in 

 E. bellidifolium, or sometimes nearly equalling those of E. speciosurii, to 

 which this species is evidently allied. Rays pale purple or blue, sometimes 

 nearly white. — The pubescence is exceedingly variable, and we have a full , 

 series of specimens, connecting the most hairy forms with the nearly smooth 

 and glabrous plant. 



* ♦ Exterior pappibs of manifeB, subulate or squamcllate setcE: rays nearly in a 

 single series. 



23. E. pumilum (Nutt.) : very hirsute throughout with spreading rigid 

 hairs; stems numerous from the same root, or ca3spitose, simple or sparingly 

 branched, terminated by solitary heads ; leaves entire, lanceolate or linear, 

 tapering to the base ; the radical and lowermost linear-spatulate, tapering into 

 a petiole ; rays somewhat in a double series, twice the length of the very 

 hirsute involucre ; achenia sparsely hairy ; exterior pappus setaceous-subu- 

 late, very shovi.— Nutt. ! gen. 2. j;. 147, Sfin trans. Amer. phil. soc. I. c. ; 

 DC. jnodr. 5. p. 286. E. hirsutum, Pursh ! fl. 2. p. 742, not of Lour. 



Upper Missouri, Bradbury! Nuttall! Mr. Nicollet! and plains of the 

 Platte near the Rocky Mountains, Nuttall ! May-June.— Stems 6-10 inches 

 high, rather stout, clothed like the leaves with almost hispid hairs, simple or 

 forked, or rarely divided into 3 or 4 branches, naked at the summit, bearing 

 snigle heads nearly as large as those of E. alpinum. Leaves rather rigid ; 

 the lowest 2-3 inches long, including the margined petiole, 2-3 lines wide 

 near the apex. Rays white. Bristles of the inner pappus 15-20, scabrous, 

 slightly shorter than the corolla; the exterior rather fewer, very sliort, but 

 forming a distinct outer series.— In Nuttall's Genera, the pappus is said to be 

 "double, the internal short, about 12-rayed": in Mr. Nuttall's recent me- 

 moir it is said to be single, of about 20 rays. The exterior pappus is abun- 

 dantly manifest in all tlie specimens we have examined. 



24. E. concinnum: very hirsute throughout with long spreading hairs; 

 stems several from the same root or caudex, slender, leafy, branching above ; 

 the branches or peduncles terminated by single heads; leaves narrowly 

 linear, elongated, entire, attenuate at the base, the lowermost tapering into a 

 petiole ; rays narrowly linear, numerous (about 50), in a single series, twice 

 the lencrth of the very hirsute involucre; achenia (immature) hirsute; ex- 

 terior pappus setose-scjuamellate. — Distasis ? concinna, Hook. Sf Am. ! bat. 

 Beecliey, suppl. p. 350. 



" Snake River, below the Salmon Falls in the Snake Country" (interior 

 of Oreeon), Mr. Tolmie! — Stems about a span high; the plant hoary or 

 canescent with the hirsute pubescence, resembhng the preceding species, but 

 much more slender throughout. Heads about the size of a Daisy ; the rays 

 in the dried specimens bright blue. Inner pappus of 8-10, or more commonly 

 12-15, hispid-scabrous bristles, nearly the length of the corolla : the exterior 

 fe~wer, somewhat chail-like, squamellate-subulate (as in Chrysopsis), form- 

 ing a distinct outer pappus, rather shorter than the ovary. Receptacle areo- 

 lafe. Appendages of the style, as in all the genus, very short and obtuse. 



