silk tree
棔 refers specifically to the silk tree, a flowering tree known for its delicate, silky blossoms.
棔 combines 木 (tree) with 昏, which likely contributes the sound and may relate to dusk or dimness, possibly referring to the tree's appearance or blooming time.
A tree 木 with a dusk-like 昏 quality: imagine a silk tree whose pink, silky flowers look like a soft sunset glow.
For コン, picture a silk tree with a cone-shaped cluster of blossoms: cone -> コン, and the tree's flowers form a cone.