10 
upwards, with 3—4 teeth, the ribs deeply furrowed so that the 
stems are regularly 6—8 furrowed with as many sharp ribs. Often 
confounded with the var. anceps of the preceeding species. 
Am.: Kotzebue Sound, Nottingham Island in Hudson Strait, West 
Greenl. 60°—70° (!), Eur.: Spitsbergen (!), Beeren Island, Samoyede Land, 
Kolguevy, Novaya Zemlya to 74°. As.: Mouth of the Yenissei, Lena and 
Kolyma, Chukches Land. 
Geogr. area: Northern North America, Northern Scandinavia, 
Northern Russia, Siberia. 
Sect. II. Subvernalia A. Br. Summergreen. Fertile and sterile stems con- 
temporaneous, branched, fertile stem at first umbranched whitish, afterwards 
green and branched. Spike blunt. 
18. E. silvaticum L. 
Rothrock, Fl. of Alaska p. 459; Lge. Consp. FI. Groenl. p. 193. FI. D. 
t 1182? 
Sterile and at last also fertile stems producing compound verti- 
cillate spreading or deflexed branches. Sheaths loose with ce. 10 teeth, 
compounded to 8 or 4 irregular blunt lobes. 
Am.: Kotzebue Sound, West Greenl. 60°—70° (!). The monstr. poly- 
stachyum Milde, with small spikes on the upper branches, has been 
found in West Greenl. 64° 29’ (!). 
Geogr. area: Northern North America, Iceland, Fzerdes, Northern 
and Central Europe, Northern Asia. 
Sect. III. Vernalia A. Br. Fertile stems vernal, rather succulent and_ pale, 
umbranched. Sterile stems aestival, branched. Spike blunt. 
19. E. arvense L. 
Hook. Coll. of Arct. Pl. p.123; Taylor, Pl. coll. at Davis Str. and Baff. 
Bay p. 87; Lge. Consp. Fl. Groenl. pl. 191; Hart, Brit. Pol. Exped. p. 142; 
Peary, Auxil. Exped. App. C. p.9; Macoun, Catalogue V, p. 249; Ledeb. FI. 
Ross. IV, p. 486; Trautv. Consp. Fl. Noy. Semlja. p. 87, Syll. Pl. Sib. bor. 
orient. p.545, Fl. Kolym. p.573; Kurtz, Fl. d. Tschuktschenh. p.482; Nath., 
Spetsb. Karlv. p. 39; Th. Fries, Beeren Isl. Veget. p. 156; Reichhardt, Fl. 
Jan Mayen p. 10; Feilden, Fl. of Kolgueyv. p. 184, Nov. Zemlya, p. 25; 
Schmidt, Fl. Jeniss. arct. p.130. Fl. D. t. 1942, 2001. 
Fertile stems with loose, 5—10 toothed sheaths, sterile stems 
branched, sheaths slightly enlarged, teeth 6—12 triangular, lanceo- 
late. Branches about 4 ribbed, teeth of the sheaths herbaceous, 
divergent, lowermost sheath of the branches green or brown opaque. 
In Arctic regions forms often occur on which the fertile stems 
in the lower part are more or less branched, also, but more seldom, 
sterile fronds with a little spike on the top. The branches are 
generally simple, but sometimes branched. Teeth on the sheaths 
of the branches are often 3, varying to 4 or 5. These forms are 
however not sharply separated from each other. 
