48. Polygonum viviparum, L.—Hook. Fl. Bor. Am. ii. p. 130.
Amentaceæ, Juss.
49. Salix Richardsoni, Hook. Fl. Bor. Am. ii. p. 147, Tab. 182.
50. Salix vestita, Ph.—Hook. Fl. Bor. Am. ii. p. 152.
51. Salix Arctica, Br.—Hook. Fl. Bor. Am. ii. p. 152.
52. Betula glandulosa, Mx.—Hook. Fl. Bor. Am. ii. p. 156.
53. Betula nana, L.—Hook. Fl. Bor. Am. ii. p. 156.