Genus 52. . GRASS FAMILY. 217 



1. Trisetum spicatum (L.) Richter. Narrow False Oat. Fig. 523. 



Aira spicata L. Sp. PI. 64. 1753. 

 Aira subspicata L. Syst. Veg. Ed. io, 673. 1759. 

 Avena mollis Michx. Fl. Bor. Am. 1 : 72. 1803. 

 Trisetum subspicatum Beauv. Agrost. 180. 1812. 

 T. spicatum Richter, PI. Europ. 1 : 59. 1890. 



Softly pubescent or glabrous, culms 6'-2 G tall, erect, 

 simple. Sheaths usually shorter than the internodes; 

 ligule 4"-l" long; blades i'-4' long, 4 "-2" wide; panicle 

 spike-like, i'-s' in length, often interrupted below, its 

 branches i4' or less long, erect; spikelets 2-3-flowered, 

 the empty scales hispid on the keel, shining, the second 

 about 24" long, the first shorter; flowering scales 2"- 

 24" long, acuminate, scabrous, each bearing a long bent 

 and somewhat twisted awn. 



In rocky places, Labrador to Alaska, south on the moun- 

 tains to North Carolina, New Mexico and California. Also 

 in Europe and Asia. Downy Oat-grass. Aug.-Sept. 



2. Trisetum flavescens (L.) Beauv. Yellow False Oat. Fig. 524. 



Avena flavescens L. Sp. PI. 809. 1753. 

 Trisetum pratense Pers. Syn. 1 : 97. 1805. 

 T. flavescens Beauv. Agrost. 88. 181 2. 



Culms ii°-2i° tall, erect, simple, smooth and gla- 

 brous. Sheaths shorter than the internodes, more or 

 less pubescent; ligule 4" long; blades i4'-s' long, 

 i"-3" wide, scabrous, sometimes sparingly hairy; 

 panicle open, 2'-s' in length, the branches ascending 

 or erect, somewhat flexuous, naked below, the lower 

 i'-2' long; spikelets 3-4-flowered ; empty scales 

 smooth and glabrous, the second acute, 24" long, the 

 first about half as long, narrower, acuminate ; flow- 

 ering scales 24"-3" long, scabrous, bearing a long 

 bent and twisted awn. 



Introduced into Missouri and Kansas. Native of 

 Europe and Asia. Panicle yellow, turning dull brown. 

 Golden, Tall or Yellow Oat-grass. July-Aug. 



3. Trisetum pennsylvanicum (L.) Beauv. Marsh 

 False Oat or Oat-grass. Fig. 525. 



Avena pennsyhvanica L. Sp. PI. 79. 1753. 



Avena palustris Michx. Fl. Bor. Am. 1 : 72. 1803. 



Trisetum pennsylvanicum Beauv.; R. & S. Syst. 2: 658. 181 7. 



Trisetum palustre Torr. Fl. U. S. 1 : 126. 1824. 



Culms i°-3° tall, erect, simple, slender and often weak, 

 smooth and glabrous. Sheaths shorter than the internodes, 

 sometimes scabrous ; ligule 4" long; blades i'-6' long, 

 i"-3" wide, rough; panicle 2 r -8' in length, yellowish, nar- 

 row, the branches ascending, the lower i'-a' long; spike- 

 lets 2-flowered ; outer scales smooth, shining, subequal, the 

 second 2"-24" long; flowering scales 2"-24" long, scabrous, 

 the lower not long-awned, but a rudimentary awn some- 

 times present, the upper with a long bent and twisted awn. 



In swamps and wet meadows, Massachusetts to Illinois, south 

 to Florida and Louisiana. Ascends to 3500 ft. in Virginia. 

 Panicle sometimes loose and nodding. June-July. 



