Species in the genus Caesalpinia:

Caesalpinia decapetala var. japonica / Jaketsuibara ジャケツイバラ

Caesalpinia decapetala var. japonica is a deciduous liana with sharp thorns on branches, inhabiting lowland forest edges or riversides, creeping up on plants. Leaves are of bipari-pinnate leaf, with 3-8 pairs of pinnules, each with 5-12 lobes, 1-2.5cm long, 5-10mm wide, long oblong. Pedicles and rhachises also have many retrorse prickles on each of them. Twenty to thirty-centimeter-long racemes put yellow flowers in them. The 5-petaled flowers measure 2.5-3cm in diameter; the upper petals are smaller than the other four and have long red stripes. Stamens surrounding pistils are red, which cover pistils. Bloom time: May-June.