Crossword puzzle clue "trees related to aspens"

POPLAR, a genus of rapidly growing trees of the willow family

ALAMO, (Spanish) a kind of poplar tree

CEDAR, a large evergreen coniferous tree

FIR, an evergreen tree

(German) vowel change in related words, esp. that in Indo-European, which survives in English in e.g. sing, sang, sung, song

a skin disease caused by inflammation of the sebaceous follicles, esp. on the face, neck, and shoulders

a sense of hearing