328 A Gray—North American Flora. 
Juniper, and a Yew; those of Canada proper are four or five 
Pines, four Firs, a Larch, an Arbor-Vite, three Junipers, and 
a Yew,—fourteen or fifteen to three. Of Amentaceous trees 
and shrubs, Great Britain counts one Oak (in, two marked 
forms), a Beech, a Hazel, a Hornbeam, two Birches, an Alder, 
a Myrica, eighteen Wiilows, and two Poplars,—twenty-eight 
species in nine genera, and under four natural orders. In 
Canada there are at least eight Oaks, a Chestnut, a Beech, two 
Hazels, two Hornbeams of distinct genera, six Birches, tw 
Alders, about fourteen Willows and five Poplars, also a Plane 
tree, two Walnuts and four Hickories; say forty-eight species 
In thirteen genera, and belonging to seven natural orders. 
The comparison may not be altogether fair; for the British 
flora is exceptionally poor, even for islands so situated. But if 
we extend it to Scandinavia, so as to have a continental and a0 
equivalent area, the native Conifers would be augmented only 
y one Fir, the Amentacez by several more Willows, a Pop: 
lar, and one or two more Birches;—no additional orders no? 
genera. 
_ If we take in the Atlantic United States, east of the Missis- 
sippi, and compare this area with Europe, we should find the 
species and the types increasing as we proceed southward, but 
about the same numerical proportion would hold. 
