﻿102 PLANTS FENDLERIAN.E. 



Nutt., which I referred to Hymenoxys in the Flora of N. America, is doubtless distinct, 

 as Mr. Nuttall insists.* The naturalists of the Exploring Expedition met with this 



HYMENOTHRIX, Nov. Gen. 



Capitulum multiflorum, heterogamum ; fl. radii 8-10 ligulatis foemineis, disci tubulosis. Involucrum tur- 

 binatum, disco brevius, e squamis circiter 10 lanceolato-oblongis, subbiseriatis, sequalibus, appressis. Kecep- 

 taculum parvum, planum, nudum, papillosum. Ligula; spathulato-oblonga?, apice 3-dentata?, discum haud 

 superantes. Corollce fl. hermapb. elongate, tubo gracili minutim glanduligero, fauce infundibuliformi 5-loba 

 lobisque margine vix incrassatis glabris. Anlherae ecaudata?, exsertas, appendicula ovata superatoe. Sty li 

 rami fl. hermaph. lineares, cono brevi superati. Achenia lineari-cuneata, sub 4-5-gona, glabriuscula. Pap- 

 pus simplex, radii et disci conformis, corolla paulo brevior, e setis 12- 13 equalibus sursum barbellulalis infra 

 medium membranula hyalina lanceolata integerrima utrinque limbalis. — Herba annua? amara, subglabra ; 

 caule erecto corymboso; foliis alternis petiolatis biternatisectis, segmentis integris vel trifidis lobisque lineari- 

 bus ; capitulis corymbosis ; floribus radii et disci flavis. 



s H. Wislizeni. — Grassy places, Ojo de Gallejo, between El Paso del Norte and Chihuahua, August, Dr. 

 Wislizenus. — Stem two feet high, rigid, loosely and amply corymbose at the summit; the branches, leaves, 

 involucre, &c, minutely appressed-puberulent. Lower leaves triternately, the upper biternately, dissected ; 

 those of the branches 3-5-parted, or the uppermost simple; the segments a line or less in width, half an 

 inch or more in length. Heads 4 lines long, on slender and minutely bracteate peduncles; the fully de- 

 veloped flowers nearly twice the length of the herbaceous and appressed involucre. Disk-corollas 3 lines in 

 length, fully as long as the spreading rays ; the sinuses between the ovate lobes slightly unequal. Branches 

 of the style narrowly linear, semicylindrical or more flattened, glabrous, or minutely puberulent on the back, 

 the prominent stigmatic lines extending to the base of the short, minutely bearded cone with which they are 

 tipped. Pappus longer than the achenium, formed of narrow and diaphanous palea; with a very strong midrib 

 which is gradually excurrent into a prolonged, barbellate-denticulate awn. — I know of no genus of Euhele- 

 nieoe with which this plant can be immediately compared, except CliEetymenia, Hook. Sf Am. (in Bot. Beech., 

 which the authors refer to Tagetinece), Burrielia, DC, and Oxypappus, Benth. In habit, foliage, &c, it is 

 very unlike either of these: the pappus is much as in the former; but the style differs widely from the 

 description and figures of this and the last-named genus. 



* It appears to me almost certain that botli Plilomeris and Dichcvla of Nuttall should be united to Burri- 

 elia, DC, with the character a little extended as to the pappus. Plilomeris affinis, Nult. in Jour. Acad. 

 Philad. (n. ser.) 1. p. 174, differs from P. aristata s. Californica, Nult., only in having the scales of the pappus 

 minutely pectinate-ciliate down the sides ; and from P. coronaria, Null., only in the want of awns. A specimen 

 of P. tenella, Null. 1. c, accords exactly in the pappus, and sufficiently so in other respects, with the anterior P. 

 mutica, Nutt. The achenia of the ray are certainly fertile in some specimens of several, if not all, of these 

 plants ; nor do I find them infolded in the involucral scales any more than in Burrielia. The subjoined species 

 technically belongs to Dichrela, but differs from Burrielia (especially B. gracilis) only by having very short 

 and obtuse scales of the pappus interposed between the aristiform ones, and in the sparingly lobed leaves : — 

 / Dich^ta Fremontii (Torr. ined.): caulibus e radice annua adscendentibus gracilibus ; foliis anguste 

 linearibus nunc integerrimis nunc segmenta filiformia utrinque 1-2 gerentibus ; squamis involucri et ligulis 

 late ovalibus 8 ; pappo ex aristis 4 e basi subulata setiformibus tubum gracillimum corolla subsuperantibus et 



