KOELREUTERIA

Koelreuteria Laxm., Novi Comment Acad. Sci. Imp. Petrop. 16: 562. 1772; Fl. China @ eFloras.org 12: 9.

Trees or shrubs, rarely climbers, deciduous, polygamo-dioecious (having bisexual and male flowers on some plants, and bisexual and female flowers on others) or polygamo-monoecious (having male, female and bisexual flowers on the same plant). Leaves alternate, imparipinnate or bipinnate, exstipulate, climbers stipulate; leaflets alternate or opposite, usually serrate, rarely entire. Thyrses terminal, rarely axillary, large; branches many, spreading. Flowers small, unisexual, polygamous with male, female and bisexual, actinomorphic or zygomorphic, usually 5-merous, hypogynous. Sepals usually 5, rarely 4, unequal, outer 2 smaller, valvate. Petals usually 4, sometimes 5, slightly unequal in length, adaxially with 2-lobed scales at base, clawed. Disk thick, apex often crenate. Stamens often 8, sometimes fewer, inserted on disk; filaments free, often villous. Ovary 3-locular, ovules 2 per loculus, on upper half of middle axis; style short or slightly longer; stigma 3-lobed or entire. Capsules swollen, ovoid, ellipsoid or subglobose, trigonous, loculicidal into 3 schizocarps, wall of schizocarps membranous, reticulate. Seeds 1 per locule, globose, aril absent, testa black, crustaceous.

3 species

Koelreuteria bipinnata

Koelreuteria bipinnata Franch., Bull. Soc. Bot. France 33: 453. 1886; Fl. China @ eFloras.org 12: 9; K. bipinnata var. puberula Chun, Acta Phytotax. Sin. 3(4): 408. 1955; K. bipinnata var. bipinnata; K. integrifolia Merr., Philipp. J. Sci. 21(5): 500. 1922.

Trees, up to 20 m tall. Branches tuberculate, lenticels orbicular to elliptic. Leaves exstipulate, alternate, spreading, bipinnately paripinnately compound, petiolate; petiole up to 9 cm long, pulvinate at base; rachis up to 60 cm long; pinnae up to 12 in number, alternate, 8.5-24 cm long, rachillae 4-12 cm long, with a narrow adaxial groove, densely pubescent, petiolules 1-2.5 cm long; leaflets 6-16 per pinna, alternate or subopposite, leaflet petiolules 3-7 mm long, pubescent, leaflet lamina obliquely ovate, 4-10 cm x 2-3.5 cm, papery or subleathery, apex acuminate, base broadly cuneate, rounded or oblique, margin incurved, serrate, adaxial surface glabrous, abaxial surface pubescent, especially on veins; basal leaflets of pinnae sometimes 2-3 lobed. Thyrses spreading, large, 35-70 cm long, pubescent with pedicels.

(Flowers pale yellow, small, fragrant. Sepals 5, connate up to middle, lobes broadly triangular or elliptic, hispidulous and fimbriate glandular, margin erose. Petals 4, oblong-lanceolate, 6-9 x 1.5-3 mm, apex obtuse or acute, claw 1.5-3 mm, villous; adaxially with 2 deeply-lobed scales. Stamens 8, 4-7 mm long; filaments spreading, white villous; anthers short and sparsely hairy. Ovary trigonous- ellipsoid, pilose.) (Flowers not observed)

Capsules pale purplish red, brown when mature, ellipsoid or subglobose, trigonous, 4-7 cm x 3.5-5 cm, apex obtuse or rounded, mucronate; loculicidal into 3 schizocarps, valves of schizocarps ellipsoid to subcordiform, abaxially reticulately veined, adaxially shiny. Seeds subglobose, 5-6 mm in diameter.

Flowering and Fruiting: June to October
Common Names: Chinese flame tree, Chinese golden rain tree, Bougainvillea golden rain tree