GEAMINE^. (grass FAMILY.) 647 



•"■ ++ Hispid or hairy on the sheaths, at least the lower: spikelets mostly scattered on 

 slender or capillary pedicels in an ample, loose, at length very effuse panicle: 

 culms mostly branched from the base, erect or ascending (10' -20' high). 



7. P. oapillkre, L. (Old-witch Grass.) All the sheaths and usually 

 the leaves copiously hairy or hispid; panicle mostly very compound, the branches 

 divaricate when old ; spikelets varying from ovoid to narrowly oblong, pointed ; 

 lower glume half the length of the neutral pate which is longer than the elliptical 

 obtuse perfect flower. — Sandy soil and cultivated fields everywhere. Aug. - Oct. 

 — Varies extremely in size and appearance : in depauperate forms the spikelets 

 only I", in the larger forms 1 J" in length. 



8. P. autumn^e, BoscI Root perennial ■? lower sheaths and margins 

 of the small narrow leaves more or less hairy, otherwise glabrous, except some 

 bristly hairs in the main axils oftlie very effuse capillary panicle, its much elongated 

 divisions sparingly branched, or even simple and terminated with solitary spindle- 

 shaped spikelets; lower glume minute; perfect flower lanceolate-oblong and pointed, 

 nearly equalling the lance-oblong obtusish upper glume and the neutral palet. 

 (P. nudum, Walt. 1 P. dichotomiflorum, ifichx. P. divergens, Muhl., not of 

 H.B.K. P. fragile, Kunth.) — Sand-hills, Mason County, Illinois (Mead, E. 

 Hall), and southward. 



^- ^- H- Sterile flower staminate, of 2 palets: lower glume more than half the length 

 of the upper : spikelets large (2"- 2^" long), ovate, pointed, as are tlie glumes, Sfc: 

 perennials, glabrous, with tall or stout and rigid upright culms. 



9. P. virg&tum, L. Tall (3° -5° high); leaves very long, fiat; ligule 

 silky-bearded; branches of the compound loose and large panicle (9' -2° long) at 

 length spreading or drooping ; spikelets scattered, usually purplish. — Moist sandy 

 soil : common, especially southward. Aug. 



10. P. amirum, Ell. Culms (1^° high) sheathed to the top ; leaves in- 

 volute, glaucous, coriaceous, the uppermost exceeding the contracted panicle, the simple 

 racemose branches of which are appressed ; spikelets pale. — Sandy shores, Con- 

 necticut {Barratt, Bobbins), Virginia, and southward. Aug., Sept. 



» * Panicle loosely spreading or diffuse, short or small : perennials. 



I- Lower (sterile) jhwer neutral, or in No. 11, and sometimes in No. li, staminate, 



formed of 2 palets, the upper one scarious and sometimes small and inconspicuous. 



++ Culm-leaves broadly lanceolate or wider, with 9-15 principal nerves. 



11. P. latifblium, L. Culm (l°-2° high) smooth; the joints and the 

 orifice of the throat or margins of the otherwise smooth sheaths often bearded with 

 soft woolly hairs; leaves broadly oblong-lanceolate from a heart-clasping base (often 1' 

 wide), taper-pointed, 11 -15-nerved, smooth, or sparingly downy-hairy; panicle 

 more or less exserted {2' -3' long), usually long-peduncled, the branches spread- 

 ing; spikelets obovate, 1^" long, downy; lower glume ovate, not half the length 

 of the many-nen-ed upper one ; sterile flower often (not always) with 3 stamens. 

 (P. Walteri, Pair. ) — Moist thickets : common. June - Aug. 



12. P. clandestinum, L. Culm rigid (10-3° high), very leafy to the 

 top, at length producing appressed branches, the joints naked; sheaths rough 

 with papillcc bearing very stiff and spreading bristly hairs; leaves oblong-laneeolate 

 from a heart-clasping base, very taper-pointed ; lateral and usually also the ter- 



