PANICDM GRAMINE^E 719 



minate only. Glumes 4, the 3 lower membranous, empty or the 

 third with a staminate flower, the fourih chartaceous, shining, 

 enclosing a palet of similar texture arid a perfect flower. Sta- 

 mens 3. Styles distinct. Stigmas plumose. Grain free, enclos- 

 ed in the hardened fruiting glume. 



* Spikelets in pairs, one sessile the other pedicelled, crowded on one 

 side of simple flattened branches which are digitately clustered at the 

 top of the stem : lower flower neutral, of a single palet. 



P. SANGUINALE L. Sp. 57, Stems erect or decumbent, 1-3 feet long, 

 often rooting at the lower nodes, smooth : leaves 2-6 inches long, 2-|4 lines 

 broad, acuminate : spikes 3-10, narrowly linear, 2-6 inches long, digitate or 

 in approximate whorls at the summit of the stem : rachis flat, margined : 

 spikelets lanceolate, acute. In fields and waste places throughout North 

 America and Europe except the extreme north. 



* Spikelets disposed in panicles, awnless. 

 *- Annual. 



P. capilare L. Sp. 58. Stem erect or decumbent, 1-2 feet long, sim- 

 ple or sometimes branched: sheaths pilose-hirsute: leaves 6-12 inches 

 long, 3-8 lines broad, more or less pubescent: terminal panicle 3-14 inches 

 long, its lower branches at first included in the upper sheaths, finally ex- 

 serted and widely spreading, 2-10 inches long: spikelets 1-1 ^ lines long, 

 acuminate. In dry soil, throughout most parts of North America and 

 Europe. 



*- -*- Perennials. 



P pubescens Lam. Encycl. iv, 748. Stems at first erect and simple, 

 later profusely branched and leaning or ascending : sheaths hirsute to 

 villous, often papillose : leaves rounded-truncate or often narrowed at base, 

 those of the stem 2-3 inches long, those of the branches much shorter : 

 primary panicle less than 3 inches long, ovoid, the branches ascending: 

 spikelets hardly a line long, pubescent. In dry soil, eastern Washington 

 to the Eastern States. 



P. dichotomum L. Sp 58. Smooth and glabrous or the lower nodes 

 bearded : stems erect, 6-24 inches high, at first simple, later profusely di- 

 chotomously branched at about the middle: leaves light green, generally 

 much narrowed toward the base, the primary ones distant, 2-3 inches long 

 by 2-3 lines broad, those of the branches much smaller, sometimes invo- 

 lute: primary panicle usually long-exserted 1-2 inches long, the branches 

 loose and spreading, bearing few glabrous ellipsoid spikelets about a line 

 long. In dry woodlands, Washington to the Eastern States. 



P. Scrilmeriannm Nash Bull. Torr, Bot. Club xxii, 421. Stems 

 erect, 6-24 inches high, simple or later in the season dichotpmously branch- 

 ed above, sparingly pubescent: sheaths shortly papillose-hispid, sometimes 

 glabrate : leaves 2-4 inches long, 3-6 lines broad, rounded or truncate at 

 base, acuminate, more or less spreading, smooth above, scabrous beneath : 

 panicles small, the primary one exserted, ovoid, 1-3 inches long, its bran- 

 ches spreading 8-12 lines long, often flex.uous : spikelets turgid obovoid, 

 about 1> lines long. In dry or moist soil, eastern Washington to the 

 Eastern States. 



P. Scoparium Lam. Encycl. iv, 744. ? Stems spreading, 6-24 inches 

 long, geniculate at the lower nodes and at length branched : leaves lanceo- 

 late, 3-5 inches long, 4-6 lines broad, mostly erect and somewhat rigid; 

 hairy beneath and fringed with spreading hairs at base : sheaths hairy 

 panicle 2-3 inches long nearly simple, the simple branches bearing a few 



