3 Rhodora [January 



Panicle-branches smooth or nearly so: lemmas 2.3-2.8 mm. 



long, firm in texture 7. P. laurctdiana. 



Panicle-branches strongly scabrous: lemmas thin in texture. 

 Lemmas 2.5-3 mm. long: grain 1.4 1.6 mm. long. 



8. /'. macra. 

 Lemmas 2 mm. long or less: grain 1-1.2 mm. long. 



9. P. airoides. 



D. Lemmas essentially entire 11. I' ■ paupcrcula. 



B. Grain 1.8-2.5 mm. long. F. 



F. Flowering culms stout : leaves 2.6-6 mm. wide: lower panicle- 

 branches densely floriferous nearly to the base: midrib of 

 the coriaceous lemma prolonged to the apex, often excurrent 



as a short mucro 4. /'. rupestrit. 



F. Flowering culms slender: leaves 0.5-2 mm. wide: lower 



panicle-branches floriferous chiefly above the middle: lemma 



with hyaline margin; its midrib not excurrent. G. 



G. Glumes and lemmas serrulate and erose-ciliolate under 



a lens. 



Gray-green: panicle-branches ascending or spreading, 



not reflexed, smooth or nearly so: lemmas firm, 2.3- 



2.8 mm. long 7. P. luurcntiaua. 



Bright-green: panicle-branches at length reflexed, sca- 

 brous: lemmas thin and lustrous, 3-4 mm. long. 



10. P. lucida. 

 G. Lemmas essentially entire, not ciliolate. 



Lemmas 2-4 mm. long, tapering to a blunt point or obtus- 

 ion: second glume 2-3 mm. long: panicle 0.2-1.8 

 dm. long. 

 Lemmas 2-2.5 mm. long: panicle 1-0 cm. long. 



11. P. paupercula. 

 Lemmas 3-4 mm. long: panicle 0.3 1.8 dm. long. 

 (11.) P. paupercula, var. alaakana. 

 Lemmas 4.5-6 mm. long, acute or acuminate: second 

 glume 7-9 mm. long: panicle 1-2.5 dm. long. 



(11.) P. paupcrcula, var. longiglumis. 



* Anther 1.5-2.2 mm. long: perennials, often, stoloniferoua late in the 



season (usually after anthesis). 



1. P. maritim.v (Huds.) Pari. Figs. l-(>. Coarse; the smooth 

 culms 2-8 <lm. high, forming dense clumps: leaves pale, firm, usually 

 involute in age, 0.25-1.7 dm. long; ligule 1-3 mm. long, entire, blunt- 

 pointed: panicle 0.45-2.7 dm. long, usually somewhat exserted; the 

 ascending or finally spreading, but not reflexed, branches and the 

 pedicels scabrous: spikelets 0.5-1.2 cm. long, 4-11 -flowered: 1st 

 glume 2.2-3.4 mm. long, 3-nerved, acute; 2d glume ovate, 3-4.5 mm. 

 long, 3-nerved, tapering abruptly to a short apex: lemma 4-5 mm. 



