noun
palmate venation; palmate vein
Botanical term describing a leaf vein pattern where several main veins radiate from a single point, like fingers from a palm.
カエデの葉は掌状脈を持つ。
Maple leaves have palmate venation.
羽状脈 refers to pinnate venation, where veins branch off a central midrib like a feather, unlike the radiating pattern of 掌状脈.
Compound of 掌状 (palm-shaped) and 脈 (vein). The exact historical derivation is uncertain, but the term is a straightforward descriptive compound in botanical terminology.