102 XE: PLANTEH FENDLERIANZE. 
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 ; fi. radii 8— 10 ligulatis foemineis, disci tubulosis. Involucrum tur- 
binatum, disco brevius, e squamis circiter 10 lanceolato-oblongis, subbiseriatis, equalibus, appressis. Recep- 
taculum parvum, planum, nudum, papillosum. Ligulz spathulato-oblonge, apice 3-dentate, discum haud 
superantes. Corolle fl. hermaph. elongate, tubo gracili minutim glanduligero, fauce infundibuliformi 5-loba 
lobisque margine vix incrassatis glabris. Anthere ecaudate, exserte, appendicula ovata superate. Styli 
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 barbellulatis infra 
medium membranula hyalina lanceolata integerrima utrinque limbatis. — 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. 
H. Wistizent. — 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 palez with a very strong midrib 
which is gradually excurrent into a prolonged, barbellate-denticulate awn. —I know of no genus of Euhele- 
nie with which this plant can be immediately compared, except Cheetymenia, Hook. § Arn. (in Bot. Beech., 
which the authors refer to Tagetinewe), 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. 
_” * Tt appears to me almost certain that both Ptilomeris and Dicheta of Nuttall should be united to Burri- 
elia, DC., with the character a little extended as to the pappus. Ptilomeris affinis, Nutt. in Jour. Acad. 
Philad. (n. ser.) 1. p. 174, differs from P. aristata s. Californica, Nutt., only in having the scales of the pappus 
minutely pectinate-ciliate down the sides; and from P. coronaria, Nuéé., only in the want of awns. A specimen 
of P. tenella, Nutt. 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 Dicheta, 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 : — 
Dicnzta Fremonti (Torr. ined.): caulibus e radice annua adscendentibus gracilibus ; foliis anguste 
linearibus nune 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 corolle subsuperantibus et 
