﻿86 PLANTiE FENDLERIAN.3E. 



prairies, said to have been made by the buffaloes in wallowing. — The rays are brown 

 only at the base. 



f398. C. involtjcrata, Nutt. in Trans. Am. Phil. Soc. (n. ser.) 7. p. 360. Hollows 

 in the prairies near 110 Creek ; Sept. (444). — The achenia are obovate, repand-trun- 

 cate at the apex, scarcely 2-toothed, entirely awnless ; the margins hispid. 



f399. Cosmos bipinnatus, Cat: Ic. 1. p. 9. /. 14. "Woodland, ten miles west of 

 Las Vegas ; Aug. (447.) — Rays smaller than in Mexican specimens ; the achenia only 

 two-awned. (No. 448 is an autumnal specimen of the same, in fruit ; from Santa Fe.) 

 400. Cosmidium gracile, Ton. §• Gray, Fl. 2. p. 350. Santa Fe, at the foot of 

 irrigating ditches ; and on the Rio del Norte ; May to Sept. (445.) (Also gathered by 

 Fremont on the Upper Platte and Arkansas, and by Wislizenus on the Arkansas, and 

 again at Albuquerque.) — The specimens are all rayless, like that of Dr. James. The 

 corolla is yellow, but turns brownish in fading. The mature achenia are narrowly linear, 

 straight or nearly so, 4 lines long, more or less tuberculate ; their base cohering with that 

 of the chaff, with which they fall away ; the abrupt apex bearing two short and diverging 

 retrorsely barbed persistent awns. — There is a third species, with simple leaves, in Dr. 

 Gregg's collection.* 



S 401. Bidens tenuisecta (sp. nov.) : annua, glabriuscula, caule ramoso tereti ad- 

 scendente ; ramis striato-angulatis apice nudo 1 - 3-cephalis ; foliis (oppositis alternisve) 

 bipinnati partitis vel biternatisectis, segmentis linearibus integerrimis seu 2-3-lobatis 

 rachi paulo latioribus ; squamis involucri hirsuti linearibus; ligulis 5 -8 inconspicuis dis- 

 cum vix aequantibus ; acheniis attenuato-linearibus glabris subtetragonis striatis breviter 

 2-aristatis. — Margins of Pofii Creek (between Bent's Fort and Santa Fe) ; Oct. (449.) 

 — Plant one or two feet high, with a very smooth stem. Segments of the leaves seldom 

 over a line in width, and, except the lowest, little wider than their rachis. Heads 

 rather larger than those of B. bipinnata, and with a greater number of disk-flowers. The 

 naked peduncles in the wild specimens are 5 or 6 inches long, bearing a single head ; in 



nating the stem or the few short branches, on thick peduncles of only half an inch in length. Involucre an 

 inch in diameter. Sterile ray-achenia nearly smooth, with a short pappus : fertile achenia 3 lines long ; the 

 stout awns about the same length, three or four times the length of the rigid lacerate-denticulate squamellas. 

 Although different in aspect from the described species, it agrees in floral characters with Tithonia. 

 / * Cosmidium simplicifolium (sp. nov.) : caulibus e radice perenni simplicibus 1 -3-cephalis ; foliis rigi- 

 diusculis filiformi-linearibus integerrimis ; squamis involucri exterioris ovatis parvis, interioris ad medium con- 

 natis ligulis obovato-cuneatis apice trilobis multo brevioribus ; acheniis valde immaturis dentibus 2 squamaefor- 

 mibus retrorsum hispidis coronatis (maturis ignotis). — High and dry land, battle-field near Buena Vista, 

 Coahuila, Dr. Gregg ; May. — Leaves two inches long ; the radical ones slightly dilated upwards. Ligules 

 half an inch long. 



