290 CONTRIBUTIONS FEOM THE NATIONAL HERBARIUM. 



cushion of soft foliage at base, the short blades spreading; panicles rather densely 

 flowered, the broad spikelets commoDly purple or bronze. 



9. Poa epilis Scribn. Frequent above timber line, in meadows. B. C. to Colo, 

 and Mont. — Plants pale, in dense leafy tufts, the blades narrow, flexuous, folded, 

 rough; panicles dense, pale, and shining. 



10. Poa gracillima Vasey. Frequent above or near timber line, in meadows or on 

 rocky slopes. B. C. to Calif, and Mont. — Plants in loose bunches with a mass of 

 spreading foliage at the base, the culms commonly 25 to 40 cm. tall, the pale purple- 

 tinged spikelets 6 to 10 mm. long. 



11. Poa sandbergii Vasey. At high and middle altitudes, in meadows or on rocky 

 slopes. B. C. to Calif., Colo., and Mont. — Plants in small dense tufts, often purplish 

 at base, the leaves crowded at the base, the short blades commonly curled, the flexuous 

 panicles mostly 5 to 8 cm. long, the spikelets ashy-purple. 



12. Poa lucida Vasey. Belton, in open gravelly soil. Alta. to N. Mex. and 

 S. Dak. — Plants in dense tufts, with slightly scabrous blades and narrow pale shining 

 panicles, the short erect branches spikelet-bearing from near the base. 



22. PANICULAKIA Fabr. 



Tall marsh grasses with flat blades and open panicles, the spikelets with short thin 

 glumes and strongly nerved, obtuse lemmas. 



Spikelets linear, 12 mm. or more long, pale 1. P. borealis. 



Spikelets oval, not over 6 mm. long, dark green or purple. 



Lemmas with 5 prominent nerves, the summit white and delicate. 



2. P. pauciflora. 

 Lemmas with 7 prominent nerves, only the very tip delicate. 



Blades mostly 3 to 7 mm. wide 3. P. nervata. 



Blades 8 to 10 mm. wide 4. P. nervata elata. 



1. Panicularia borealis Nash. Bog at Johns Lake, Vreeland. Alaska to Calif., 

 N. Mex., N. Y., and Me. {Glyceria borealis Batchelder.) — Culms commonly 1 meter 

 tall, rather thick and lush; blades ascending, 5 to 8 mm. wide; panicle 20 to 40 cm. 

 long, the rather few slender branches stiffly ascending or spreading, the spikelets 

 short-pediceled toward their ends. 



2. Panicularia pauciflora (Presl) Kuntze. At low altitudes, in swamps or along 

 streams. B. C. to CaUf., Colo., and Mont. {Glyceria pauciflora'Presl.) — Plants rather 

 fltout, 40 to 80 cm. taU, with creeping rootstocks, rough spreading blades 8 to 12 mm. 

 wide, and nodding many-flowered panicles with flexuous branches; spikelets 4 to 6 

 mm. long, the white summits of the lemmas contrasting with the green or purple 

 body, 



3. Panicularia nervata (Willd.) Kuntze. At low altitudes, in wet soil. Alaska to 

 Mex., Fla., and Lab. (Glyceria nervata Trin.) — Culms 60 to 100 cm. tall, often in 

 large clumps; blades spreading; panicles drooping; spikelets 3 to 4 mm. long. 



4. Panicularia nervata elata (Nash) Piper. At low and middle altitudes, in wet 

 soil. B. C. to Calif, and Mont. (Glyceria elata Hitchc.) — Plants on the average 

 taller than in the preceding, vsrith broader laxer blades and larger panicle, the 

 spikelets 4 to 5 mm. long. 



23. PUCCINELLIA Pari. 



1. PuccineUia nuttalliana (Schult.) Hitchc. East entrance, in low alkali spots on 

 prairie. B. C. to Calif., N. Mex., and N. Dak. — A tufted slender perennial with 

 narrow blades and a relatively large, erect panicle with slender stiff flexuous spread- 

 ing branches naked at the base; spikelets grayish purple, 4 to 7 mm. long. 



