Note 197 — Chapter II
Reading edition
M. Meyen (Geog. of Plants, p. 302) and Mr. Balfour (Botany, p. 567) suppose that in America 40° is about its limit; and this is the case in regard to its extensive cultivation; but it is grown certainly as high as 52°, perhaps as high as 54°, north latitude: see Richardson's Arctic Expedition, 1851, vol. ii. pp. 49, 234.