Description from Flora of China
Trees or shrubs (or woody vines with tendrils in Cardiospermum and allied genera), rarely herbaceous climbers. Indumentum usually of simple hairs, often glandular on young parts, buds, and inflorescences. Leaves alternate, usually estipulate; leaf blade pinnate or digitate, rarely simple; leaflets alternate to opposite, entire or dentate to serrate. Inflorescence a terminal or axillary thyrse; bracts and bracteoles small. Flowers unisexual, rarely polygamous or bisexual, actinomorphic or zygomorphic, usually small. Sepals 4 or 5(or 6), equal or unequal, free or connate at base, imbricate or valvate. Petals 4 or 5(or 6), sometimes absent, free, imbricate, usually clawed, often with scales or hair-tufted basal appendages. Disk conspicuous, fleshy, complete or interrupted, lobed or annular, rarely absent. Stamens 5-10(-74), usually 8, rarely numerous, variously inserted but usually within disk, often exserted in male flowers; filaments free, rarely connate; anthers dorsifixed, longitudinally dehiscent, introrse; staminodes sometimes present in carpellate flowers, but filaments shorter and anthers with a thick wall, indehiscent. Ovary superior, (1-)3(or 4)-loculed; ovules 1 or 2(or several) per locule, placentation axile, rarely parietal, anatropous, campylotropous, or amphitropous; style usually apical (terminal), semigynobasic in Allophylus [gynobasic in Deinbollia Schumacher & Thonning]; stigma entire or 2 or 3(or 4)-lobed, usually rudimentary in male flowers. Fruit a loculicidal capsule, berry, or drupe, or consisting of 2 or 3 samaras, often 1-seeded and 1-loculed by abortion. Seeds 1(or 2 or more) per locule; testa black or brown, hard, often with a conspicuous fleshy aril or sarcotesta; embryo curved, plicate, or twisted, oily and starchy; endosperm usually absent. 2n = 20-36.
There is some variation in the circumscription of Sapindaceae in taxonomic treatments, particularly with regard to the inclusion of genera from the closely related, predominately temperate families Aceraceae and Hippocastanaceae. Several studies including Müller and Leenhouts (in Ferguson & Müller, Evolutionary Significance Exine: 407-445. 1976), and more recently those based on molecular data (Stevens, Angiosperm Phylogeny Website, 2001 onward; Harrington et al., Syst. Bot. 30: 366-382. 2005), supported the recognition of a broadly defined Sapindaceae incorporating Aceraceae and Hippocastanaceae. Harrington et al. (loc. cit.) proposed four subfamilies or clades, comprising Sapindoideae (including Koelreuteria and Ungnadia Endlicher), Dodonaeoideae, Hippocastanoideae (including taxa previously referred to Aceraceae and Hippocastanaceae, plus Handeliodendron), and a monotypic "Xanthoceratoideae". Within Hippocastanoideae, Acer Linnaeus and Dipteronia Oliver comprise a monophyletic group and are treated in this Flora as Aceraceae. Similarly, Aesculus Linnaeus, Billia Peyritsch, and the Chinese endemic Handeliodendron Rehder form a monophyletic group and are treated here as Hippocastanaceae. There is some support for "Xanthoceratoideae" being the first lineage to diverge within the broadly defined Sapindaceae assemblage; consequently, Xanthoceras is treated separately from genera in Sapindoideae and Dodonaeoideae in the following account of Sapindaceae s.s. The sequence of genera reflects Müller and Leenhouts (loc. cit.) as modified by recent analyses based on molecular and morphological data, rather than following the order developed by Radlkofer (Sitzungsber. Math.-Phys. Cl. Königl. Bayer. Akad. Wiss. München 20: 105-379. 1890; and in Engler, Pflanzenreich 98a-h(IV. 165): 1-1539. 1931-1934), which was previously followed in FRPS.
The main economic uses of this family include (1) timber: Amesiodendron chinense, Dimocarpus longan, D. confinis, Litchi chinensis, Pavieasia kwangsiensis, and Pometia pinnata; (2) fruit: Dimocarpus longan, Litchi chinensis, and Nephelium lappaceum; (3) medicine: Dimocarpus longan (arillode), Litchi chinensis (seeds), and Sapindus saponaria (roots); (4) oil: Amesiodendron chinense, Delavaya toxocarpa, and Xanthoceras sorbifolium. Saponins occur widely in the family, commonly used as a fish poison and for their detergent properties.
Lo Hsien-shui & Chen Te-chao. 1985. Sapindaceae (excluding Handeliodendron). In: Law Yuh-wu & Lo Hsien-shui, eds., Fl. Reipubl. Popularis Sin. 47(1): 1-72.
One hundred thirty-five genera and ca. 1500 species: widely distributed in tropical and subtropical regions, especially well represented in tropical SE Asia; 21 genera (one endemic) and 52 species (16 endemic, one introduced) in China.
(Authors: Xia Nianhe (夏念和); Paul A. Gadek)