576 GRAMINEJS. (GKASS FAMILY.) 



hand, differing from Panicum meiely in the want of tlie lower glume ; which, 

 however, is occasionally present in some species, as a small scale. Glume and 

 empty palea few-nerved. Flower coriaceous, mostly orbicular or ovate, flat on 

 the inner.side, convex on the outer. Stamens 3. — (Said to have been a Greek 

 name for Millet.) 



* Spikes very numerous in a spiked raceme ; their thin and inembranaceous or folia- 

 ceoiis rhaclds h-oader than the spikelets, and keeled or boat-shaped. 



1. P. flUitailS, Kunth. Glabrous; stems procumbent below and rooting 

 in the mud or floating; leaves lanceolate; rhachis (1" wide) projecting beyond 

 the small slightly pubescent spikelets into a tapering point, scabrous on the 

 back. (J) (Ceresia fluitans, £^.) — Eiver-swamps, Virginia, S. Ohio, Illinois, 

 and southward. Oct. 



* * Spikes one or few ; the rhachis narrower Hum the spikelets. 

 1- Spikelets vei-y obtuse, orbicular : spikes one terminal, and often 1-5 lateraT. 



2. P. setnceum, Michx. Culm ascending or decumbent (1°- 2° long), 

 slender; leaves (2" wide, flat) and sheaths clothed with soft spreading hairs; 

 spikes very slender (2' -4' long), smooth, mostly solitary on u loTig peduncle, and 

 usually one from the sheaths of each of the upper leaves on short peduncles or included ; 

 spikelets (J" wide) nairowly 2-rowed. 1|. (Also P. debile and P. ciliatifoliura, 

 Michx.) — Sandy fields, Massachusetts, near the coast, to Illinois, and southward. 

 August. 



3. P. Iseve, Michx. Culm upright, rather stout (l°-3° high) ; the pretty 

 large and long leaves with the flattened sheaths smooth or somewhat hairy ; 

 spikes 2-6, the lateral ones somewhat approximated near the summit of an elon- 

 gated naked peduncle, spr&aAmg (2' -4' long), smooth, except a bearded tuft at 

 their base; spikelets broadly 2-rowed (over 1" wide). IJ. 1 — Moist soil, S. New 

 England to Kentucky, and southward. August. — Either glabrous or sometimes 

 the lower sheaths, &c. very hairy. 



4- -i- Spikelets acute: spikes always a pair at the summit of the naked peduncle. 



4. P. disticlmm, L. (Joint-Geass.) Nearly glabrous, rather glau- 

 cous; culms ascending (about 1° high) from a long creeping base ; leaves linear- 

 lanceolate (2'-3' long) ; spikes short and closely-flowered (3'-2' long), oneshort- 

 pedunclcd, the other sessile ; rhachis flat on the back ; spikelets ovate, slightly pointed 

 (barely Ij" long). 1). (P. notatum, Fluegge, Sj-c.) — Wet fields, Virginia and 

 southward. July - Sept. 



5. P. Digitaria, Poir. Culms ascending (1°-2J° high) from a creeping 

 base; leaves lanceolate (3' -6' long, J'-^' wide); spikes slender and rather 

 sparsely flowered (l'-4' long), conjugate, both sessile at the apex of the slender 

 peduncle; spikelets ovate-lanceolate (2" long). (Milium paspalodes, EU.) — Vir- 

 ginia (Pursh), and southward. 



59. PAWICUM, L. Panic-Grass. 



Spikelets panicled, racemcd, or sometimes spiked, not involuci-ate, lJ-2- 

 flowered. Glumes 2, but the lower one usually short or minute (rarely want- 

 ing), membranacco-herbaceous ; the upper as long as the fertile flower. Lower 



