100 Rhodora [June 
lanceolate-cordate, short-caudate, coarsely and bluntly serrate, 1.5- 
4 em. long, 4-35 mm. broad: peduncles glandular-pilose: heads 
hemispherical, 3-4 mm. high, 3-5 mm. in diameter; outer involucral 
bracts sparsely glandular-pilose; receptacle conical; chaff pale brown, 
linear, minutely ciliate; ray-flowers pistillate, purple, equalling or 
slightly exceeding their achenes, ligule 3-toothed, cruciform, the 
lateral teeth widely divergent, corolla-tube broad, pilose, achene 
obdeltoid, angular, hispid, 2 mm. long, pappus firm, white, longer 
than the corolla-tube, linear, fimbriate and long-aristate; disc-flowers 
perfect, corolla yellow, the tube exceeding the achene, pappus firm, 
white, linear, and long-aristate, equalling or slightly exceeding the 
corolla-tube, achenes obdeltoid, hispid, 1.5-2 mm. long. 
Mexico: altitude 4000-5500 feet, Tumbala, Chiapas, Oct. 20, 
1895, E. W. Nelson, no. 3,356 (rype in Gray Herb.). Costa Rica: 
altitude 4,250 feet, Cartago, Prov. Cartago, Oct., 1887, Juan J. 
Cooper, no. 5,815, in part; altitude 1,500 m., San Rafael de Cartago, 
Aug. 28, 1892, H. Pittier, no. 6,989. 
Recently introduced in eastern North America. MASSACHUSETTS: 
shore of Charles River between Mass. Ave. and Anderson Bridge, 
Cambridge, Sept. 26, 1916, F. S. Collins, no. 3,797. 
4. G. AnISTULATA Bicknell, Bull. Torr. Bot. Cl. xliii. 270 (1916). 
G. parviflora Cav., y. hispida DC., Prodr. v. 677 (1836), not G. 
hispida Benth. 
Native of South and Central America, introduced and becoming 
very common in the eastern United States. In 1866 it was found 
by Joseph Blake at Gilmanton, New Hampshire. 
5. G.: PARVIFLORA Cav., Icon. Deser. Pl. iii. 41, t. 281 (1795). 
Native of South and Central America, and Mexico, introduced 
in the United States, where it is casual, especially near the larger 
cities, from the Atlantic to the Pacific coast. Dr. Gray in his Man- 
ual ed. 2, 225 (1856) reports the plant on waste places at Cambridge, 
New York, and Philadelphia. 
6. G. semicalva (Gray) comb. nov. G. parviflora Cav., var. 
semicalea Gray, Pl. Wrightianae ii. 98 (1853). This native species 
of the mountains of northern Mexico and the southwestern states 
was first collected by Charles Wright in 1851, and described by Asa 
Gray as a variety of G. parviflora. Wright’s no. 1,268, the type of 
var. semicalva has, as Gray pointed out, the ray achenes glabrous and 
lacking pappus. Wright’s no. 1,267, collected in the same region, 
has the ray-achenes "slightly hairy near the summit, and furnished 
with a very small setiform pappus." This collection Gray identified 
with G. caracasana, a purple-flowered species. Wright’s no. 1,267 does 
not appear to have purple rays. Its natural affinity seems to the 
writers to be with G. semicalva, the slender native species of that region. 
An inspection of these two specimens, and others from the adjacent 
regions, shows that the ray-achenes may be hispidulous at summit 
