1897] NORTH AMERICAN SPECIES OF AMBLYSTEGIUM 285 
AMBLYSTEGIUM KocHII Br. & Sch. Plate XII. fig. 5. 
Synon.: Amblystegium kochii Bruch & Schimper, Bry. Eur. Ambly. 13. 
pi. 6. 1853.—Schimper, Syn. Muse. Eur. (1st ed.) 596. 1860. (2d ed.) 716. 
1876.— Milde, Bry. Siles. 327. 1869.— Hartmann, Skand. FI. (10th ed.) Io. 
1871.— Husnot, Musc. Gall. 362, A/. zog. 1894.— Dixon & Jameson, Stud. 
Handb. 449. AZ. 56. 1896. 
Amblystegium curvipes Guembel, Bry. Eur. Ambly. 14. f/. 7. 1853.— 
Schimper, Syn. Musc. Eur. (ist ed.) 597. 1860, (2d ed.) 717. 1876.— 
Macoum & Kindberg, Cat. Can. Pl. 6:220. 1892. 
Amblystegium ambiguum De Notaris, Epil. Bry. Ital. 144. 1869. 
Amblystegium trichopodium var. kochit Lindberg, Acta Soc. Sci. Fenn. 
10:275. 1872.— Braithwaite, Brit. Moss Fl. 3:30. A/. 89. 1896. 
Amblystegium riparium var. kochit R. duBuysson, Ess. anal. gen. Ambly. 
20. 1883.—Boulay, Musc. Fr. 77. 1884 
TYPE in Herb. Guembel, Berlin. 
Gametophyte bisexual, of medium or large size, forming wide 
loose tufts, ordinarily pale, light green, to yellow: stems pros- 
trate, 2 to 4™ long, flattened or obscurely angled, 180 to 300 
in diameter, cortex well differentiated, of two to three layers of 
cells, these 6 to 134 in diameter; central strand 30 to 35m, of 
ten to fifteen rows of cells; cells of ground tissue 13 to 35m in 
diameter ; branches prostrate, ascending or sometimes erect, I to 
3™ long: leaves long acuminate from a broadly-ovate or ovate base, 
acumen slender, two-thirds the length of the body, sometimes 
equaling it or even longer; leaf attaining greatest width in the 
basal eighth, varying from serrulate in the middle leaf region to 
distinctly serrate throughout, costate, costa distinct, extending 
through two-thirds to three-fourths the length of the leaf, ceas- 
ing in the base of the acumen, one-sixth to one-fifth the leaf base 
at the line of insertion, 60 to 85u wide ; many ranked, commonly 
widely Spreading from the base in all directions, scarcely different in 
the dry condition, more or less crowded, 5 30H wide by 1400p 
long, ranging in width from 350 to 64om and in length from 
TIOO to 1500p; leaf cells parenchymatous in basal eighth, prosen- 
chymatous above, cells of alar region oblong to short oblong, occa- 
sionally quadrate, 15.7mwide by 25.8u long, varying in width from 
II to 17 and in length from 18 to 28m, the marginal two to three 
