fg TRIANDRIA.— x¥ONOGYNIA. 



HAB. Bog-meadows. Aug. If. A foot and ahalj 



high, angul. ; leav. pubesc. ; spik. lateral and term. ; 



brist. 3—4. 

 Q. pumila : culm pubescent above ; leaves smooth ; 



throat of the sheaths hairy ; spikes 1 — 3, terminal. 

 HAB. Wet sandy places. Aug. Culm 3 — 6 in. high ; 



spikes mostly 3 ; pet. ovate-lanceol. ; brist. 3 — 4. 



42. CENCHRUS. Burr-grass. Graminece. 



C. echinatus : spike with the flowers approximated ; 

 involucrum subglobose, villose; culm compressed. 



HAB. Sandy arid soils. Aug. 0. Erect, or pro- 

 cumb., 1 — 2 ft. long; involucrum spiny , cartilagi- 

 nous. 



(3. tribuloides : spikes and margin of the sheaths white, 

 pubescent. 



HAB. Sea-coast and near salt-water. Aug. 0. A 

 foot high ; leav. eonduplicate ; rachis and involucr. 

 very white. 



43. SPARTINA. Marsh-grass. Graminece. 



I. S. cynosuroides : spikes numerous, (10 — 40,) pedun- 

 culate, panicled, spreading; leaves broad, flat, at 

 length convolute ; calyx with a short awn on one 

 of the glumes ; style 2-cleft at the summit. 

 HAB. Salt marshes. Aug. ^. 4— 9 ft. high; leaves 

 2 — 4 ft. long ; fl. closely imbricate ; style bifid. 



i. S. juncea : leaves distichous, convolute, spreading ; 

 spikes few, 1 — 3, pedunculate ; peduncles smooth ; 

 corolla rather obtuse ; styles 2. 

 HAB. Sea coast, and gait marshes. July — Aug. il . 

 Root creeping ; culm 18 in high, slender, rigid; cal. 

 very unequal ; anth. purple. 



\. S. glabra: leaves concave, erect ; spikes alternate, 

 sessile, erect, appressed ; corolla nearly smooth on 

 the keel ; style cleft about half way down. 

 HAB. Borders of salt-marshes. Aug. — Sept. U 

 Very smooth, 3—5 ft. high ; spikes 8 — 14; anth. 

 yellow. 



44. ORYZOPSIS. Graminece. 

 0. asperifolia : culm nearly naked ; leaves erect 



