Keyed Out #048 — Platanus × acerifolia

Question 1

Broad, hand-shaped blades sit singly up the shoot, and each leaf stalk is swollen and hollow where it meets the twig, fitting over the winter bud like a snuffer, so no bud stands exposed above the leaf scar.

Accepted Answer

sycamore family

Question 2

Every hanging winter ball breaks apart into hundreds of dry, one-seeded {achenes}, each carrying a brush of stiff bristles at its foot that floats it off on the wind, rather than a nut cradled in a woody cup or cone.

Accepted Answer

Platanaceae

Question 3

Coal smoke and city grime never darken this trunk for long, and by late summer a scatter of stiff, curling chips the size of a playing card collects around its foot.

Accepted Answer

the dead outer bark is shed in plates, exposing pale new bark beneath

Question 4

Anyone pruning it while the leaves are still expanding ends up coughing, yet those same leaves are almost smooth to the touch by midsummer.

Accepted Answer

new growth is clothed in branched hairs that are shed as it hardens

Question 5

Its pendulous fruit stalks carry the bristly balls, each 1 to 1.5 inches (2.5 to 4 cm) across, in twos, not one riding alone at the tip and not a string of three to six.

Accepted Answer

Platanus × acerifolia

Question 6

The blade is cut only about a third to halfway toward the centre, into 3 to 5 broad lobes roughly as long as they are wide, above a base cut straight across or notched, rather than slashed nearly to the midrib into narrow tapering lobes.

Accepted Answer

Platanus × acerifolia