194 Fernald — American and Old Wo?'ld Birches. 



Plate VI, figs. 25 to 32, B. microphylla. 



Figure 25. — Leaf of young shoot of B. microphylla from the Altai Mts., 



Siberia (ex, herb. St. Petersberg). 

 Figure 26. — Leaf of B. fruticosa, var. cuneifolia, Regel (syn. B. microphylla, 



Bunge) from the Altai Mts., Siberia — after Kegel, Men. Bet. (1861) 



t. 7, fig. 18. 

 Figure 27. — Leaf of fruiting branch of B. occidentalis, Nutt. {B. fontinalis, 



Sargent) from Idaho Springs, Colorado {Engehnann). 

 Figure 28. — Small leaf from fruiting branch of B. occidentalis, Nutt. {B. 



fontinalis, Sargent) from Coulee City, Washington {Lake and 



Hull, No. 790). 

 Figure 29. — Leaf of young shoot of B. occidentalis, Nutt. {B. foyitinalis, 



Sargent) from the Black Hills, South Dakota {Rydberg, No. 1006). 

 Figure 30. — Leaf of fruiting branch of original material of B. alba, subsp. 



soongorica, /? microphylla, Regel, from the Tyan Shan Mts., 



Central Asia (Semenow). 

 Figures 31, 32. — Leaves of fruiting branch of B. occidentalis, Nutt. {B. 



fontinalis, Sargent) from Laramie Peak, Wyoming {A. Nelson, 



No. 1647). 



Plate VI, figs. 33 to 38, B. pumila. 



Figure 33. — Leaf of sterile shoot of B. pumila from Anticosti, Quebec 



(Macoun). 

 Figure 34. — Leaf of sterile shoot of B. alpestris. Fries, from Lapland 



(Laestadius). 

 Figure 35. — Tip of branch from Bonne Esperance, Quebec (Allen, No. 70). 

 Figure 36.— Leaves of glabrate form from Bay of Islands, Newfoundland 



(Waghorne). 

 Figure 37. — Leaves of B. alpestris, Fries, from Norway — after Lange, Fl. 



Dan., Suppl. t. 37. 

 Figure 38. — Leaves of young branch of B. alpestris. Fries, from Lapland 



{Andersson, No. 186), 



Plate VI, figs. 39, 40, B. glandulosa. 



Figure 39. — Leaf of branch from Mt. Washington, New Hampshire (J. A. 



Allen). 

 Figure 40. — Leaves of branch from Hopedale, Labrador {Sornborger, No. 



80). 



Plate VI, figs. 41 to 44, B. glandulosa, var. rotundifolia. 



Figure 41. — Leaf from Mt. Washington, New Hampshire. 



Figures 42, 43. — Leaves from Nunivak Island, Behring Sea (J. M. Macoun). 



Figure 44. — Leaf from the Altai Mts., Siberia (ex. herb. St. Petersb.). 



Plate VI, figs. 45, 46, B. nana. 



Figure 45. — Fruiting branch from Grenjadastad, Iceland {Elizabeth Taylor). 

 Figure 46. — Scale from same, enlarged three times. 



Plate VI, figs. 47 j 48, B. nana, var. Michauxii. 



Figure 47. — Fruiting branch from Grand Lake, Newfoundland {Waghorne). 

 Figure 48. — Scale from same, enlarged three times. 



