176 SALICACEAE 
pointed, border without notches or teeth, bright green above, pale beneath. 
Pedicel of capsule more than 4 as long as capsule and style. Bogs, 
throughout our area. 
29. §. herbacea, L. (Fig. 6, pl. 22.) Dwarr WItLtLow. Prostrate 
matted shrub with rounded leaves and catkins with few flowers. Height 
from 1 to 6 in. On the summits of the White Mountains. 
One stamen only in the axil of the bract or rarely two 
30. §. Uva-ursi, Pursh. (Fig. 5, pl. 22.) Brarserry Wittow. A 
prostrate herb-like shrub, generally less than 6 in. high, with crooked 
stems and egg-shaped or elliptic leaves, which are generally less than 
3 in. long and 3 or 1/3 as wide, broadest toward apex, slightly toothed. 
Catkins on lateral leafy bases, the pistillate becoming quite long. On 
the summits of the White Mountains and Adirondacks. 
z. POPULUS, L. 
Pistillate and staminate catkins on different trees. Each staminate 
group containing from 8 to 30 stamens. Bract at base of stamens slit. 
Buds without hairs, scaly, resinous. Leaves on long slender leaf-stalks, » 
broad, heart-shaped or oval. Catkins long and drooping. Large trees 
with soft wood. 
Leaves permanently covered beneath by a dense, white, silky coat . . P. alba 
Leaves usually only when young covered beneath by a dense silky coat : 
ete <8 e. -, « Pe ‘heteropinm 
Leaves never covered by dense white coat. 
Leaves narrowly egg-shaped, with rounded leaf-stalks . . P. balsamifera 
Leaves broadly egg-shaped, with leaf-stalks flattened laterally. 
Borders coarsely and deeply toothed . P. grandidentata 
Borders finely toothed, leaves short- pointed at. the apex P. tremuloides 
Leaves with long and slender points. 
Bases) often’ rounded) 47. os ac eel siete telnet ite P. nigra 
Bases generally rounded out . . . . « «2 « = e« P. deltoides 
1. P. alba, L. (Fig. 3, pl. 24.) Wutre Poprar. SILVER-LEAF Pop- 
LAR. Large tree. Leaves somewhat obliquely 4-sided (rhombic) with 
deep sinuous cuttings. Under surface of leaves permanently covered 
by a dense, white, silky coat. March-May. 
2. P. heterophylla, L. (Fig. 1, pl. 24.) Swamp or Downy Poprar, 
Large tree. Leaves egg-shaped with, usually, a somewhat heart-shaped 
base. When young the leaves are covered beneath by a white silky coat 
which usually disappears as the leaf matures. In moist places mostly 
in the southern half of our area. April-May. 
3. P. balsamifera, L. (Fig. 2, pl. 24.) BatsamM Porrar. Large 
tree. Buds large and varnished, shining, resinous. Leaves broadly egg- 
shaped, finely notched at borders, smooth, shining above and beneath. 
Leaf-stalks round. 
Var. P. balsamifera candicans, Gray, is the Balm of Gilead tree common 
in cultivation. P. balsamifera is found throughout our area. April. 
4. P. grandidentata, Michx. (Fig. 4, pl. 24.) Laror Toornrep ASPEN. 
Leaves rounded-egg-shaped, sharply tapering at apex, with very conspieu- 
ous, irregular teeth. Bark rather smooth, greenish. Leaves at ex- 
tremities of branches only. Rich woods throughout our region. April. 
5. P. tremuloides, Michx. (Fig. 5, pl. 24.) AMERICAN ASPEN. 
Wuite Portar. Leaves rounded, heart-shaped at base, sharply tapering 
