GRAMINKyE. (GRASS FAMILY.) 645 



2. P. 'Walterianum, Schultes. Perennial ; leaves linear, short ; spikes 

 3-7, the lowest i)artl}- ineliuled in the sheath of the uppermost leaf, the rhaciiis 

 blunt; spikclets glabrous. (1'. vaginktuni, ^//.) — Low or wet grounds, New 

 Jersey (Cape May, Auttall), Delaware (Tatnall, Canby), and southward. 



* * Sjiikes with n narrow loiiKjIess rhnehls : perennials, or moslli/ so. 

 ■<- Spikc/cis verij obtuse, orbicuLtr : s/>i/ces one terminal and often 1-5 lateial. 



3. P. set^eeum, Michx. Culm ascending- or decumbent (1°- 2° long), 

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

 spikes lerji slender (2' -4' long), smooth, mostli/ solitunj on a long peduncle, and 

 usnnllij one from the sheaths of each of the upper Icanes on short peduncles or included; 

 spikelels (i" wide) narrowly 2-rowed. (Also P. debile and P. ciliatifolium, Michx.) 

 — Sandy fields : common from E. Mass. to Illinois, southward. Aug. 



4. P. Iseve, Michx. Culm upright, rather stout (l°-5o high) ; the pretty 

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

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

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

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

 land to Kentucky, and southward. Aug. — Either glabrous or sometimes th« 

 lower sheaths, &c. very hairy. As here received this perhaps comprises two or 

 more species. 



-I- -1- Spikelets acute: spikes always a pair at the summit of the naked peduncle. 



5. P. distichum, L. (Joint-Gisass.) Nearly glabrous, rather glaucous ; 

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

 ceolate (2' -3' long); spikes short and closely-flowered (9" -2' long), one short- 

 peduncled, the other sessile ; rhaciiis flat on the back ; spikelets orate, slightly pointed 

 (barely I ^" long). — Wet fields, Virginia and southward. July- Sept. 



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

 base; leaves lanceolate (3'- 6' long, 4" -6" wide) ; sp/fos s/e«f/er, rather sparsely 

 flowered (l'-4' long), both sessile at the apex of the slender peduncle; spikelets 

 ovate-lanceolate (2" long). (Milium paspalbdes, Ell.) — Virginia and southward. 



60. PANICUM, L. Panic-Grass. (PI. 13.) 



Spikelets panicled, racemed, or sometimes spiked, not involucrate, 1 J- 2-flow- 

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

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

 flower either neutral or staminatc, of one palct which closely resembles the upper 

 glume, and sometimes with a second thin one. Upper flower perfect, closed, 

 coriaceous or cartilaginous, usually flattish parallel with the glumes, awnless 

 (except in §3), enclosing the free and grooveless grain. Stamens 3. Stigmas 

 plumose, usually purple. (An ancient Latin name of the Italian Millet, P. 

 Italicum (now Setaria Italicn), thought to come from panis, bread; some species 

 furnishing a kind of bread-corn.) 



§ 1. DIGIT AEIA, Scop. Spikelits crowded 2-3 together in simple nnd mostly 

 \-sidid clustered spikes or spike-like racemes, ivholly aionless and pointless: lowp.t 

 flower neutral, of a single palet : loivei- glume minute, sometimes obsolete ot jc*nt- 

 ing: root annual: plant often purplish. 



