266 FIELD COLUMBIAN MUSEUM BOTANY, VOL. II. 



and unequally sinuate-dentate, contracted below into a narrowly 

 winged petiole and subamplexicaul by a slightly auricular base: 

 inflorescence terminating the stem and branches in a paniculate 

 cyme: heads 4 to 5 mm. high, radiate: ray-flowers many- 

 seriate; corollas minute, 1.5 to 2 mm. long, less than 0.5 mm. 

 broad: disk-flowers numerous; corollas about i mm. long, 

 4-5-toothed; tube on the outer surface glandular-pilose : achenes 

 slightly compressed, produced above into a somewhat irregular 

 saucer-shaped subcartilaginous pappus. MEXICO. State of 

 San Luis Potosi: river banks, Las Palmas, 4 June, 1890, C. G. 

 Pringle, no. 3531 (hb. Field Mus.) ; and in the same locality, 18 

 June, 1892, C. G. Pringle, no. 4101 (hb. Field Mus.). 



E. Pringlei is readily distinguished from E. viscosa Less, by 

 the ovate or obovate undivided leaves, the more numerous 

 heads, shorter hairs on stem and branches, and finally by the 

 smaller narrower rays, the more conspicuously flaring pappus, 

 and the less conical receptacle. 



Erigeron pacayensis Greenman, sp. nov. 



Suffruticose : stems erect or ascending, branched, i to 1.5 

 dm. high, pubescent with upwardly appressed or but slightly 

 spreading hairs: leaves narrowly linear-oblanceolate, i to 2 

 cm. long, i to 3 mm. broad, acute or obtusish, entire or bearing 

 a single tooth on one or both margins, gradually narrowed below 

 to a subpetiolate base, sparingly pubescent on either surface to 

 nearly glabrous: heads few, small, 5 to 6 mm. high, less than 



1 cm. in diameter including the rays, terminating the stem 

 and branches on long slender appressed-pubescent peduncles 

 6 cm. or less in length: involucre subcampanulate ; bracts of 

 the involucre about 3 -seriate, unequal, lance-linear, acute, 

 appressed-pubescent, more or less purplish; the outer bracts 

 shorter: ray-flowers 3-seriate, many; rays narrow, white or 

 roseate : flowers of the disk numerous : pappus bristles slender, 



2 to 2.5 mm. long: achenes pubescent. GUATEMALA. Depart- 

 ment of Amatitlan: crater of the Volcano of Pacaya, altitude 

 2,500 m., 6 January, 1907, W. A. Kellerman, no. 6m (hb. Field 

 Mus., and hb. Gray). 



The species here proposed has its affinity with Erigeron Ervend- 

 bergii Gray, and *E. irazuensis Greenman. From the former 

 it differs in having smaller heads, appressed instead of spreading 

 hairs on the involucre, more unequal involucral bracts, etc. 

 Although similar in habit to E. irazuensis, yet it differs in several 

 particulars, namely in having narrower and less pubescent 

 leaves, also in the appressed pubescence on the stem and pedun- 

 cles, as well as in other details. 



I am indebted to Mr. H. H. Bartlett of the Gray Herbarium 

 for a critical comparison of Professor Kellerman's plant with the 

 type of E. irazuensis. 



* By oversight published as Erigeron irazuense. 



