400 



WEEDS AXD USEFUL PLAX'TS. 



ovoid-oblong, yellowisli-greeu ; bristles 4-8 in a cluster, about as long 

 as the spikelets : palege of the i^erfect floret smooth, striately punctate. 



Italian Setaria. Millet. Bens;al Grass. 



Root annual. Culm 2-4 or 5 feet high. Leaves 6-12 and 18 inches long, lance-linear, 

 rather broad, flat, serrulate on the margin ; sheathe striate, pubescent on the margin ; 

 Zi;7mZ€ beard-hke. Spil-e compound (or rather a densely contracted j3anid€), 3-6 inches 

 long, ovoid-oblong or sub-cjdindric ; rachis densely hirsute with long hairs. Bi~istles some- 

 times longer than the spikelets, yellowish. Sterile fioj-et wholly abortive, or neutral, — the 

 upper palea very minute, palea of the perfect Jioj"et smooth, minutely striate-punctate. 



Fields ; cultivated as a fallow crop. Native of Europe and India. ' Ft July. D: Aag. 



Obs. Some years ago, the culture of this plant was introduced into 

 Pennsylvania, and excited considerable interest, for a time, among the 

 farmers, — as affording valuable fodder, when the usual hay- crop "^as 

 likely to be deficient. It was soon found, however, not to be as valuahle 

 as the usual fallow crop (of Oats or Barley), of which it occupied the 

 place ; and was, moreover, remarkably liable to damage from rain. The 

 cultivation, therefore, soon declined, — and is now generally abandoned. 

 There is another species [S. verticillata, Beauv., — vrith the spike com- 

 posed of interrupted verticils of spikelets, and the involucre of retrorsely 

 scabrous bristles, in pairs.) which is becoming something of a nuisance, 

 about gardens, in many places ; but it seems scarcely, as yet, entitled to 

 a more particular notice here. 



30. CEN'CHRUS, L. Bur Grass 



[Greek, KencTiros ; the ancient name of Millet.] 



Spikelets as in Panicum, awnless, but enclosed (1-5 together) in a glob- 

 ular bristly or spinose involucre, which becomes coriaceous, forming a 

 deciduous bur in fruit. Involucres sessile in a terminal .s/^/Zre. Siyle-s 

 united below. 



1. C. tribuloi'des, L. Involucre subglobose, pubescent, spinosely 

 muricate, split on one side. 



Tkibulus-like Cexcheus. Bur Grass. Hedge-hog Grass. 



Boot annual. Culm 1-2 feet long, usually oblique or procumbent, geniculate, branch- 

 ing, smooth. Xeareo 3-6 or 8 inches long, lance-linear, acuminate, ?'y;htly scabrous on 

 the margin; sheaths loose, smooth; liguie beard-like. Raceme terminal, of 6-12 or 14 

 alternate involucrate heads or clusters : rachis angular, flexuose, slightly scabrous. Li- 

 voliLcre urceolate or subglobose, laciniate, usually split to the base on one side, hairy, 

 armed externally with rigid subulate scabrous spines, villous within, embracing 1, 2, cr 

 3 spikelets. ^^terile ^ore< mostly staminate. Sandy fields. Fl. Xag. JPa Sept. 



Obs. The plant is very abundant in sandy districts along the coast and 

 around the great Lakes,— and has found its wny to some of the slaty 

 hills of Penosylvania. It is altogether a worthless grass ; and the 

 prickly involucres are a grievous nuisance, wherever it prevails in oul- 



