150 CHARACTERS OF SOME GNAPHALIOID COMPOSITÆ. 
NEMATOPUS, nov. gen. 
Capitula biflora, homogama, in glomerulum obconico-hemisphericum 
- densissime aggregata. Znvolucrum generale pauciseriale, glomerulo 
paulo brevius; squamis appressis, oblongo-linearibus, disco paulo 
brevioribus, inter se et cum paleis receptaculi consimilibus (extimis 
2-3 magis herbaceis), apice viridulo lamina parva hyalino-peta- 
loidea aurea rotundata abrupte appendieulatis, Receptaculum gene- 
rale convexum ; partialia brevissima, arcte sessilia. Involucrum par- 
tiale biseriale ; squamis cujusque seriei circiter 5, conformibus, spa- 
thulato-linearibus vel anguste oblongis, concaviusculis, marginibus 
hyalinis, apice parce lanato lamina inflexa aurea (ut squam. glome- 
ruli) appendiculatis, exterioribus ut videtur persistentibus, non raro 
capitulis duobus, uno circ. 5-phyllo, altero 7—10-phyllo, amplecten- 
tibus. Flores hermaphroditi. Corolla 5-dentata, fauce cylindracea, 
tubo brevissimo glanduligero. Anthere breviter caudatæ. Styli 
rami breves, apice capitellati. Achenia, potius ovaria, brevia, teretia, 
glaberrima. Pappus plane nullus.— Herba annua gracili ; caule erecto 
corymboso-ramosissimo ramisque filiformibus cito glaberrimis; glo- 
merulis flavis solitariis ramulos capillares divergentes nudos termi- 
nantibus; foliis lineari-filiformibus alternis laxe lanatis glabratis. 
N. effusus. Swan River, Drummond.—Plant between a span and a 
foot in height. Glomerules a line and a half in diameter; the scales 
sparingly lanate. Scales of the glomerule, paleæ, and proper involu- 
eral scales all alike, except the interior are successively thinner and more 
scarious or hyaline, all abruptly tipped with the same short and rounded 
yellow petaloid appendage.— The plant appears to constitute a very 
distinct genus, between Shirrophorus and Gnephosis. Tt has the habit 
of the latter; but the scales, &c., are all narrow and homogeneous, the 
axis is convex (instead of cylindrical), the partial receptacles sessile (not 
stipitate), and there is no trace of pappus.—The specimen of Gnephosis 
tenuissima in the Hookerian herbarium has lost all the flowers, and 
although some achzenia remain loose in the scarious heads, I can find 
no pappus, &e., to compare with the curious and nearly-allied Pachy- 
surus of Steetz, which was abundantly gathered by Drummond. There 
is another allied plant in Drummond’s collection (No. 201 of the coll. 
1848, also in the earlier collection), which has the habit of Gnephosis, 
but with strict and very flexuous branches, a more compound glome- 
rule, the axes of the few-flowered capitula all arising from the de- 
