a. 北的

Boreal \Bo"re*al\, a. [L. borealis: cf. F. bor['e]al. See
{Boreas}.]
1. Northern; pertaining to the north, or to the north wind;
as, a boreal bird; a boreal blast.

So from their own clear north in radiant streams,
Bright over Europe bursts the boreal morn.
--Thomson.

2. (Biogeography) Designating or pertaining to a terrestrial
division consisting of the northern and mountainous parts
of both the Old and the New World; -- equivalent to the
Holarctic region exclusive of the Transition, Sonoran, and
corresponding areas. The term is used by American authors
and applied by them chiefly to the Nearctic subregion. The
Boreal region includes approximately all of North and
Central America in which the mean temperature of the
hottest season does not exceed 18[deg] C. (= 64.4[deg]
F.). Its subdivisions are the Arctic zone and

{Boreal zone}, the latter including the area between the
Arctic and Transition zones.
[Webster 1913 Suppl.] ||