Koelreuteria elegans subsp. formosana 學問
Deciduous trees, 15-17 m tall or higher. Branches ridged, pubescent. Leaves bipinnate, with petiole ca. 50 cm; leaflets 5-13; petiolules 2-2.5 cm; blades oblong-ovate, 6-8 × 2.5-3 cm, varied in shape and size, subleathery, abaxially glabrous or only barbate at vein axils, base extremely oblique, margin slightly incurved serrate or nearly entire below middle, apex long acuminate to caudate. Thyrses terminal, large, ca. 25 cm; branches and pedicels pubescent. Flowering in autumn, inflorescence of terminal panicle to 25 cm long, yellow. Sepals 5, oval or ovate-triangular, ciliate. Petals 5, lanceolate or oblong, with 2-lobed, tuberculate toothed scale, claw hairy. Stamens 7 or 8; filaments hairy. Capsules inflated, ellipsoid, 3-ridged, ca. 4 cm; carpels subcordiform, abaxially reticulate veined, adaxially shiny. Seeds black, globose, ca. 5 mm in diam.