Koelreuteria /kɛlrᵿˈtɪəriə/ is a genus of three species of flowering plants in the family Sapindaceae, native to southern and eastern Asia. They are medium-sized deciduous trees growing to 10–20 m (33–66 ft) tall, with spirally arranged pinnate or bipinnate leaves. The flowers are small and yellow, produced in large branched panicles 20–50 cm (8–20 in) long. The fruit is a three-lobed inflated papery capsule 3–6 cm long, containing several hard nut-like seeds 5–10 mm diameter. The genus was named after Joseph Gottlieb Kölreuter, from Karlsruhe, Germany, by Erich Laxmann.