Hylomecon japonica

Hylomecon japonica or yamabukiso (scientific name: Hylomecon japonica) is a perennial herbaceous plant belonging to the Papaveraceae family native to Japan and China. It grows in clusters in deciduous forests in the mountains and fields of Honshu, Shikoku, and Kyushu. The leaves have both rootlets and stems. It has an odd pinnate compound leaf and a tridentate compound stem leaf. Two to three four-petaled flowers bloom from the upper leaf axils of the stem in spring or early summer.
A similar flower Japanese kerria or yamabuki (scientific name: Kerria japonica) is a flower of a different genus (Rosaceae) , has five petals and is a tree, not a grass.

Common Name:Hylomecon japonica or yamabukiso, scientific name: Hylomecon japonica, Locality: Japan, China, Life-type: Perennial, Grass height: 30 to 50 cm, Leaf color: green, [Radical leaves] Leaf shape: odd pinnate compound leaf consisting of 5 or 7 leaves; lobes: oval; petiole: long; leaf margin: incised + serrated, [Leaves and stems] Leaves: Leaf shape: 3-depressed compound leaf, leaf order: alternate, Flowering season: April to June
Flowering place: 2-3 in the upper leaf axils; corolla: 4-petaled; diameter: 3-5 cm; flower colour: yellow/orange; number of petals: 4; number of stamens: many; fruit type: capsule; propagation: seedling; planting; use: garden planting, potted planting, park, container, medicinal use.