Keyed Out #058 — Populus tremuloides

Question 1

Its flowers have neither petals nor sepals, just a fringed scale behind a few stamens or behind a lone ovary, packed into a drooping {catkin}, and any one tree carries catkins of a single sex only.

Accepted Answer

willow family

Question 2

Each ripe {capsule} splits into valves and releases seeds so fine they are invisible without the plume of long silky white hairs that carries them off.

Accepted Answer

Salicaceae

Question 3

Winter twigs end in a true terminal bud, and each bud is sheathed in three or more overlapping, faintly resinous scales that shingle one over the next.

Accepted Answer

Populus

Question 4

The stalk carrying each leaf is flattened side-on, a thin ribbon standing edgewise to the broad blade rather than a rounded stem.

Accepted Answer

Populus

Question 5

The nearly circular blade is edged with 18 to 30 minute even teeth along each side, none of them standing more than 1 mm (0.04 inch) proud of the margin.

Accepted Answer

Populus tremuloides

Question 6

The trunk holds smooth chalky white to greenish cream bark right up into the crown, dusted with a bloom that comes off on the hand and marked with black knots and horizontal {lenticels}, roughening only at the very base of old stems.

Accepted Answer

Populus tremuloides