and Old World Birches. 179 
mens are practically identical with Rosenvinge’s Nos. 174 and 
210 from Greenland. ris shrub or dwarf tree offers consid- 
erable variation in the outline and toothing of its leaves, but 
no more than does the same form abroad ; and since the young 
branchlets and leaves are sometimes pubescent as in B. alba 
its treatment as a dwarf variety seems the wiser course, and 
the shrub may be known as Betula alba, var. minor (Tucker- 
man). 
Betula alba, var. carpatica. 
A shrub growing on Anticosti Island at the mouth of the 
St. Lawrence (Muacoun in Herb. G an., No. 23,823) 
differs somewhat markedly from other American forms. It is 
iferous branchlets the first cited specimen tends toward &. 
microphylla, Bunge. An old specimen collected by Dr. Rich- 
ardson on the Franklin Expedition (sheet No. 23,628, Herb. 
Geol. Surv. Can.) is apparently the same. 
BetTULA PENDULA. 
Betula pendula, var. japonica. 
Aside from Betula papyrifera and B. occidentalis the only 
birch of the section A/hae generally recognized in America 
until within three years has been B. populifolia, a purely 
* Spach, Ann. Sci. Nat., ser. 2, xv, 196 (1841). + Regel in DC., 1. c. 168. 
