LAMSON-SCRIBNER AND MERRILL GRASSES OF ALASKA. 75 



branches glabrous, the lower ones usually in pairs, spreading or ascending, 3 to 4 cm. 

 long, bearing a few flowers toward the apex; naked below; spikelets 3 or 4-flowered, 

 6 to 8 mm. long, purplish; glumes unequal, the first 1.5 to 2.5 mm. long, the second 

 about 2.5 to 3.5 mm. long, obtuse, 3-nerved; lemmas lanceolate, somewhat obtuse, 

 4.5 to 5 mm. long, rather prominently 5-nerved, appressed silky-pubescent on the 

 back toward the base, glabrous above; palea equaling the glume, the keels scabrous. 



Type U. S. National Herbarium no. 592344, collected by C. Wright on Arakamtchet- 

 chene, or Kayne Island (Siberia), on the Pacific Exploring Expedition under Com- 

 manders Ringgold and Rodgers, 1853-56. Distributed as "Glyceria arctica Hook." 



This was also secured at Port Clarence, by P. A. Walpole in low sandy tundra, 

 1891, 1893, and 1901, forms with less pubescent glumes than the type. A peculiar 

 species approaching Poa, but apparently quite closely related to Colpodium humile 

 Griseb. (C. bulbosum Trim), differing in its greater size and the pubescence of the 

 longer lemmas. The base of the culms in our species is somewhat thickened, as in 

 ( \ humile. 



2a. Colpodium wrightii flavum subsp. nov. 



Panicles bright yellow, otherwise as in the species. 



Type, U. S. National Herbarium no. 379007, collected August 21, 1901, low sandy 

 tundra, Port Clarence, by F. A. Walpole (no. 1891a), the only specimen seen. 



Colpodium pendulinum (Vahl) Griseb. is reported from Alaska, mouth of the 

 Klondike, R. 8, Williams « in 1899, but we have seen no specimens of this species 

 from Alaska, and accordingly have not admitted it. 



20. DUPONTIA R. Br. 



Dupontia R. Br. Suppl. App. Parry's Voy. 290. 1824. 



Spikelets 2 to 5-flowered, hermaphrodite; rachilla articulated above the glumes, 

 the callus of the lemmas distinctly hairy; glumes 2, membranaceous, awnless, exceed- 

 ing the lemma, this attenuate-pointed and entire, or finely and minutely toothed at 

 the apex . Low arctic grasses with flat leaves and small narrow or spreading panicles. 



Lemmas pilose below _ \ j) fi sc fi er i 



Lemmas glabrous _ 2 . D. psilosantha. 



1. Dupontia fischeri R. Br. Suppl. App. Parry's Voy. 291. 1824. 



Melica fischeri Spreng. Syst. Veg. 2: 32. 1827. 



Dupontia fischeri flavescens Hook. & Arn. Bot. Beechey Voy. 132. 1841. 



Graphephorum fischeri A. Gray, Proc. Amer. Acad. 5: 191. 1862. 



A slender, erect perennial, 10 to 25 cm. high, with flat leaves and contracted simple 

 panicles 4 to 7 cm. long; spikelets 2 or 3-flowered, 6 to 7.5 mm. long, with lanceolate 

 acute glumes and obtuse or acute lemmas, the latter silky-pilose on the back toward 

 the base. 



In moist soils, arctic Alaska and Seward Peninsula; also Europe and Asia. 



Specimens examined: Point Barrow, Murdoch in 1891; Port Clarence, Walpole 

 1630, 2017. 



2. Dupontia psilosantha Rupr. PI. Samoj. Cisural. 65. pi. 6. 1845. 



Poa psilosantha Rupr. loc. cit. 



Graphephorum psilosanthum Fourn. Bull. Soc. Bot. France 24: 182. 1877. 



Graphephorum fischeri psilosanthum A. Gray, Proc. Amer. Acad. 5: 191. 1862. 



A slender, erect, glabrous perennial 15 to 40 cm. high, with flat leaves and panicles 

 7 to 12 cm. long, their branches spreading, at least in flower; spikelets 6 to 7 mm. long, 

 with attenuate-pointed glabrous lemmas. 



In moist soils, Seward Peninsula and Pribilof Islands; also in Europe and Asia. 



Specimens examined: St. Paul Island, Macoun 16225; Port Clarence, Walpole 

 1792, 1822, 1882, 1982. 



« Nash, Bull. N. Y. Bot. Gard. 2: 157. 1901 



