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OF ARTS AND SCIENCES. 177 
fibres: the base of the plant covered with brown wool, as in some 
species of Cacalia: leaves including petioles a foot in length, pin- 
nate, glabrous; leaflets 4-6 pairs and an odd one, elliptic-lanceo- 
late, acute at each end; the terminal one much larger, 8-10 lines , 
long, obscurely crenate, with minute glands in the sinuses of the 
crenation; scapes a foot high, simple or branched, bearing one or 
more linear bracts: involucre double, the outer bracts narrowly ob- 
long, exceeding the broader inner ones, all obtuse: heads solitary, 
exclusive of the rays } inch in diameter: rays’ white, 4-5 lines 
long, fertile: disk flowers yellow, their corollas destitute of an 
annulus at the junction of the tube and throat: achenes slightly 
ciliate on or near the summit, but without a distinct pappus. — 
Wet meadows, Del Rio, State of Mexico, August, 1890 (n. 3668), 
This plant approaches most nearly the genus Leptosyne, differing 
from it, as heretofore limited, chiefly in its white rays and in the 
absence of an annulus on the disk corollas. The neighboring 
genera, Dahlia and Bidens, show, however, what variation is to be 
expected in the color of the rays, and in L. Mexicana, Gray, which 
Dr. Gray pronounces a good Leptosyne, there is scarcely a trace of 
an annulus. Mr. Pringle’s plant is certainly very distinct in its 
habit from any known species of the genus. 
GEISSOLEPIS, n. gen. of the Composite (Galinsogee). 
Heads heterogamous, radiate. Flowers all fertile, rays white, disk 
yellow. Involucre turbinate-campanulate; scales ovate, obtuse, 
closely imbricated in 4-5 rows, the outer regularly shorter. Re- 
ceptacle chaffy in all parts, but not alveolate; chaff obovate, ob- 
tuse, ciliate. Disk flowers regularly 5-toothed, throat not enlarged. 
Anthers entire below. Style divided nearly to the middle; the 
branches flattened, bearing short conical appendages. Achenes 4 
angled, pubescent, crowned with 7-8 very acute awl-shaped, mi- 
nutely and retrorsely ciliated scales. —A prostrate, somewhat 
succulent herb, with alternate entire linear leaves: heads small, 
solitary on lateral peduncles arising opposite the leaves. This 
genus is perhaps best placed just before Blepharipappus. The 
generic name, derived from yeieooy and denis, has reference to the 
well imbricated scales of the involucre, one of the distinctive char- 
acters of the genus. ie 
G. suapmronia. Stems prostrate, giving off numerous sub- 
simple branches: branches 4-6 lines in length, finely pubescent, 
especially at the nodes: leaves glabrous, fleshy, 6-8 lines long, 2 
half a line in breadth, sessile; _ inelnding rays $ ssichae ee 
VOL. XXVII. (N. 8. XIX.) 
