ROBINSON & GREENMAN: CONTRIB. GRAY HERBARIUM. 89 
GYMNOLOMIA, HBK. (Name. from yvuvds, naked, and 
AGpua, margin; taken by some to refer to the rays destitute of pis- 
tils, by others the achenes lacking pappus.) Heads small, medium- 
sized, or large, heterogamous, many-flowered, pedunculate, solitary 
or more often 3 to many at the ends of the branches. Involucre 
hemispherical or subcylindric; the bracts mostly numerous, in 2 to 
4 series, very variable in size and thickness, the outer mostly nar- 
row; receptacle elevated, conical, chaffy; pales conduplicate, 
entire or somewhat 3-toothed. Ray-flowers (5 to 20) in a single 
series, neutral ; ligules linear to elliptic-oblong, exserted and spread- 
ing, entire and slightly toothed at the tip, yellow or very rarely 
crimson ; disk-flowers numerous, perfect, regular, concolorous; tube 
short, cylindrical or somewhat dilated at the base, usually puberu- 
lent; throat cylindrical or narrowly campanulate; the limb 5- 
toothed. Achenes of the ray-flowers abortive and empty, of the 
disk-flowers obovoid, thickish, but more or less compressed laterally 
or 4-angled, rounded at the summit; pappus none or rarely present 
as a short cup or ring of 2 to 4 laciniate scales. Nov. gen. et 
spec., 4, 217, t. 878, 874; Gray, Proc. Amer. acad., 5, 182; Syn. 
tl, 1, pt. 2, 66, 269; Benth. and Hook. f., Gen., 2, 363; Hemsl., 
Biol. Cent.-Amer. Bot., 2, 161; Baill., Hist. pl., 8,211; Hoffmann 
in Engl, and Prantl, Nat. Pflanzenf., 4, ab. 5, 2338. Gymnopsis, 
DC., Prodr., 5, 561, in part. Heliomeris, Nutt., Journ. acad, Phila., 
ser. 2, 1,171. Zaluzania, Sch. Bip., Flora, 1861, p. 553; 1864, 
p. 216, in part.—Nearly 40 species, chiefly perennial herbs, in 
habit passing almost imperceptibly from plants of the Perymenium 
type to others of the Tithonia type. The following arrangement is 
believed to show approximately the natural affinities of the species. 
Subg. 1, Cananticarta. Corolla-tube in the disk-flowers con- 
siderably dilated at the very base, the expansion, thus developed, 
forming a sort of cap over the summit of the achene: stems shrubby, 
except perhaps in G@. tripartita: heads medium-sized; scales of the 
involucre mostly narrow. 
* Leaves rather small, i aaa entire or os undulate : scales of the 
ucre obl ping) & de btuse. P 
1. G. GREGen, Gray.” rages ected pene leaves opposite, 
ovate, obtuse, cuneate to short petioles, pale green above, white- 
tomentulose beneath, 2 to 3 cm. long (incl. petiole), 1 to 1.8 em. 
broad: peduncles long, mostly solitary at the ends of the branches. — 
