1 62 Rhodora Quly 



THE GREEN ALDERS OF NEW ENGLAND. 

 M. L. Fernald. 



Alnus viridis, DC. {A. AInobeiiila, K. Koch) is the type of a sub- 

 genus which is represented in alpine or cool situations in nearly all 

 parts of the northern hemisphere. The European shrub, A. viridis, 

 a species of mountain districts, has glabrous twigs, thinnish but finally 

 firm leaves which are glabrate and pale beneath and in maturity 3 to 

 6 cm. long, the mature fertile aments 0.8 to 1.3 cm. long, 5 to 9 mm. 

 thick. In northeastern America it is represented by two shrubs, 

 both of which have been generally referred to it. 



A. CRISPA, Pursh, El. 623 (18 14). Bctula crispa, Alton, Hort. 

 Kew. iii. 339 (1789). This is the nearest ally of A. viridis in Amer- 

 ica, but differs from the European shrub in its much firmer thick leaves 

 which are more rugose and with greener under surfaces. It occurs 

 from Labrador and Hudson Bay south to the Alpine summits of Mts, 

 Katahdin, Washington, Mansfield, and W^hiteface (New York). For 

 the identification of our alpine shrub I am indebted to Mr. Edmund G. 

 Baker of the British Museum of Natural History, who has obligingly 

 compared material of this and of the following shrub with the orig- 

 inal of Alton's Bctula crispa which proves to be essentially like the 

 firm-leaved glabrate shrub of Mt. Katahdin. 



A. mollis, n. sp. Young branches and peduncles pubescent: 

 mature leaves 4.5 to 10 cm. long, closely serrate with sharp unequal 

 teeth, and permanently covered beneath with a soft short plush-like 

 pubescence: mature fertile aments 1.3 to 2 cm. long, 0.9 to 1.2 cm. 

 thick. — Cold bogs, swamps, exposed rocky banks, etc., Newfound- 

 land to Lake Winnipeg, south to southern Maine and New Hamp- 

 shire, western Massachusetts, New York and Lake Superior. Speci- 

 mens examined : — 



Newfoundland, near Topsail, Conception Bay, August, 1901 

 {Ho7ve 6- Lang, no. 1342) ; St. John's, August i, 1894 {Robinson &> 

 Sc/irenk, no. 24) : New Brunswick, Kent County, 1870 {Fo^vler): 

 Nova Scotia, Point Pleasant, June 18, 1884 {Macoiin) ; Pictou, 

 July, 1901, Digby, July, 1901, Yarmouth, June, 1901 {Howe ^^ Lang, 

 nos. 552, 273, 46): Maine, St. Francis, Aug. 17, 1893 — no. 98, 

 Ashland. June 13, 1898 — no. 2445, Island Falls, Aug. 26, 1897, 

 Blanchard, Sept. 4, 1897, Orono, May 24 and Aug. 18. 1890, Cut- 

 ler, July I, 1902, Southport, Aug. i, 1894 {M. L. Fertiald) ; Dover, 

 May and July i, 1896 (G^. B. Fernald, nos. 5, 45, 62, 65); Man- 

 chester {Scribner) ; Northport {Furbish): New Hampshire, White 



