GBAMINEAE (GRASS FAMILY) 107 



ing, 3-6 dm. high, very slender ; sheaths usually less than half as long as the 

 internodes; blades mostly spreading, flat or involute above, 4-8 cm. long, 4 mm. 

 wide or less, the lower wider; panicle 3-6 cin. long, the flexuous branches 

 spreading ; spikelets 2 mm. long ; first glume ^ the length of the spikelet, 

 rounded ; second glume and sterile lemma densely pubescent, equaling the fruit 

 which is minutely pubescent at the apex. In the branching state forming dense 

 prostrate mats, with very numerous crowded short involute-setaceous often 

 falcate leaves. (P. filirameum Ashe ; P. neuranthum of Britton's Man., not 

 Griseb.) Sandy soil, mostly near the coast, se. Va., and south w. 



X). P. Bicknellii Nash. Culms usually stiff, erect or ascending, 2-4 dm, 

 high (rarely higher) ; nodes and lower part of the sheaths and margins sparsely 

 hairy ; blades 7-14 cm. long, 3-8 mm. wide (rarely wider), ciliate at the base, 

 rather rigid, spreading, flat, the uppermost usually the longest ; panicles 5-8 

 cm. long, the stiff slender branches bearing a few long-pediceled spikelets ; these 

 2.5 mm long ; first glume loose, \ the length of the spikelet ; second glume and 

 sterile lemma sparsely pilose or rarely glabrous, equaling the fruit or very slightly 

 exceeding it. Autumnal state ascending or erect, rather sparingly branching 

 from the upper nodes with numerous long rather stiff leaves overtopping the 

 reduced panicles of long-pediceled spikelets. (P. nemopanthum Ashe ; P. 

 Bushii Nash.) Sterile open woods and hillsides, Ct. to N. C., and Mo. 



- 4. Eudichdtoma. Culms solitary or in small tufts, slender, at first simple, 

 with lanceolate leaves and open terminal panicles; later profusely branch- 

 ing, often leaning or decumbent ; basal leaves short, forming flat rosettes 

 in the autumn,' ligule a ring of hairs less than 0.5 mm. long; spikelets 

 elliptical-oblong, not turgid ; second glume and sterile lemma 1 '-nerved. 



- Spikelets glabrous. 



27. P. dich6tomum L. Glabrous, often purplish ; culms 3-5 dm. high, erect 

 from short knotted rootstocks ; sheaths less than half the length of the inter- 

 nodes, rarely ciliate on the margins ; blades spreading, 5-11 



cm. long, 4-8 mm. wide ; panicle 4-9 cm. long, the flexuous /O\ 



branches spreading, spikelet-bearing toward the ends; spike- |jJj 



lets 2 mm. long, rather faintly nerved ; the second glume 



shorter than the fruit, exposing its summit at maturity. V 



Branching state erect, bushy-branched at the top, like a little 



tree ; the leaves croicded and spreading, more or less involute. 63. P. dichotomum. 



Woods, Me. to Mich., Fla., and Tex. Spikelets or lower Spikelet x 5. 



sheaths rarely minutely pubescent. FIG. 63. 



28. P. barbulatum Michx. In the simple state resembling large speci- 

 mens of the preceding, in larger tufts ', culms sometimes 8 dm. high ; lower nodes 

 often sparsely bearded ; sheaths usually with a puberulent ring at the summit ; 

 blades 6-10 cm. long, 6-10 mm. wide ; panicles 6-11 cm. long, as wide or wider, 

 the lower branches drooping at maturity, spikelet-bearing at the ends ; spikelets 

 2 mm. long ; second glume and sterile lemma equal, covering the fruit at maturity. 

 Autumnal state diffusely branched, forming very large top-heavy reclining 

 Inivhes, the slender branches recurved. Rocky woods and hillsides, Ct. to 

 Mich., Mo., and southw. 



29. P. yadkine'nse Ashe. Similar to P. dichotomum ; culms taller (some- 

 times 1 m. high) and stronger; sheaths usually bearing pale glandular spots; 

 blades 9-13 cm. long, 8-11 mm. wide; the basal and rameal leaves correspond- 

 ingly larger than those of P. dichotomum ; panicle about 10-12 cm. long, the 

 slender branches rather strict ; spikelets 2.5 mm. long, acute; second glume and 

 sterile lemma equal, exceeding the fruit, forming a slight beak beyond it. Au- 

 tumnal state leaning, not profusely branched. Moist woods and thickets, Pa. 

 and D. C. to Ga. ; and 111. 



30. P. lucidum Ashe. At first resembling P. dichotomum, but bright green, 

 shining, and with erect leaves; the weak culms soon becoming decumbent, 

 sometimes rooting at the nodes ; sheaths usually ciliate on the margin ; blades 

 4-7 cm. long, spreading in the decumbent state ; panicle fewer-flowered ; spikelets 

 2 mm. long; nerves more prominent than in P. dichotomum; second glume and 



