Species in the genus Rubia:

Rubia akane / Akane
Rubia chinensis var. glabrescens / Ookinutasou
Rubia cordifolia var. pratensis / Kurumabaakane
　

Rubia akane / Akane アカネ

Rubia akane is a perennial vine herb common in fields and mountains. Stems branch well, with downward-facing prickles, and leaves are 3-7cm long, in a triangular-ovate or oblong-ovate shape, with tips gradually narrowing to points and bases cordate. Two leaves in a whorl of four originate in developed stipules. As with the stems, the downward prickles are observable on petioles and leaves' backside veins. Yellow-green flowers come in cymes that emerge from axils. Boom time: August-October.