165 



Fig. 159. TRISETTJM PENNSYI.VANICUM (Linn. ) Beauv. in R. & S. Syst. 2: 

 658 1817. {Avenapeniisvlvanica Linn. 8^.^1.79. 1753; A. palitstrismchx.lSOS; 

 Trisetum palustre Torr. 1824. ) MARSH OAT-GRASS. -A slender, loosely tufted 

 perennial 6-9 dm. (2°-3°) high, with flat, soft leaves and loosely flowered, nod- 

 ding, and yellowi.sh-green panicles 5-20 cm. (2'-8') long. Sheaths shorter than 

 the internodes, somewhat scabrous; ligule 1 mm. (h") long; leaf-blades 2-15 

 cm. (l'-6') long, 2-6 mm. (l"-3") wide, scabrous. Spikelets 2-flowered with sub- 

 equal empty glumes ; floral glumes 4-5 mm. (2"-2i") long, the first awnless or 

 rarely with a rudiment, the second with a long bent and twisted awn. -On 

 moist rocks, along brooks, in wet meadows, etc., Massachusetts to Illinois, 

 south to Florida and Louisiana : British Columbia. April to June. 



