Garcinia L. section Garcinia L., Sp. Pl. 1: 443. 1753; S. W. Jones, Morphology and Major Taxonomy of Garcinia (Guttiferae), Ph. D. Thesis (unpublished): 284. 1980; Nazre et al., Phytotaxa 373 (1): 14. 2018; M. Gaudeul et al., PhytoKeys 239: 93. 2024. Type. Garcinia mangostana L., Sp. Pl. 1: 443. 1753. Description. Habit evergreen trees, sometimes with buttresses near the base of the main stem of large trees; latex yellow (i. e., G. exigua and G. mangostana var. mangostana) or white, turning yellow (i. e., G. celebica), sticky; branches decussate, horizontal or nearly horizontal; branchlets 4 - ridged, glabrous. Terminal bud concealed between the bases of the uppermost pair of petioles. Leaves decussate, small (i. e., G. exigua) or big (i. e., G. celebica and G. mangostana var. mangostana); lamina coriaceous or thickly coriaceous, glabrous; secondary veins curving towards the margin and connected in distinct loops and united into one (i. e., G. celebica and G. exigua) or two intramarginal veins (i. e., G. mangostana var. mangostana), with interrupted long wavy lines (glandular wavy lines, also called exudate containing canals) of differing lengths, running across the secondary veins to the apex or the margin; petiole grooved or not grooved above, transversely rugose, usually with a basal appendage clasping the branchlets. Inflorescences terminal, simple cymes, in a cluster of two to several flowers, or sometimes a solitary flower (in the female flowers). Flowers unisexual, plants dioecious, 4 - merous; bracteoles caducous; sepals and petals decussate. Male flowers: stamens numerous, united into a single 4 - lobed (i. e., G. celebica and G. exigua) or 4 - angled bundle (i. e., G. mangostana var. mangostana from Nazre et al. 2018), antepetalous (opposite the petals); anthers small, 2 - thecous; pistillode present or absent. Female flowers: staminodes absent or present; pistil fungiform (mushroom-shaped); ovary unlobed, usually multilocular; stigma sessile, distinctly or weakly lobed and smooth or rough. Fruits berries, subglobose, globose, depressed globose or broadly ellipsoid, small (i. e., G. exigua) or big (i. e., G. celebica and G. mangostana var. mangostana), without or with a short beak at the apex, with thick or thin pericarp, turning woody when dry; persistent stigma flattened or slightly convex, distinctly or weakly lobed; persistent sepals usually larger than in flowering materials. Seeds (1 –) 4–9, usually with a fleshy pulp. Garcinia section Garcinia is characterized by its terminal inflorescences of simple cymes (in a cluster of two to several flowers), or sometimes a solitary flower (in the female flowers); flowers with 4 sepals and 4 petals; male flowers often with a pistillode, stamens united into a single 4 - lobed or 4 - angled bundle, and with 2 - thecous anthers; usually multilocular ovaries, and stigmas with distinctly or weakly lobed and smooth or rough; and fruits with a smooth surface. A section of 15 species worldwide (Gaudeul et al. 2024); three species in Thailand (i. e., two native species: Garcinia celebica L. and G. exigua Nazre, and one cultivated species and variety: G. mangostana L. var. mangostana). Numbers of species in Garcinia section Garcinia recognized by Jones (1980), Nazre et al. (2018), and Gaudeul et al. (2024) is shown in Table 1.

Published as part of Ngernsaengsaruay, Chatchai, Chanton, Pichet, Leksungnoen, Nisa, Chaiprasongsuk, Minta & Thunthawanich, Raweewan, 2024, A taxonomic revision of Garcinia section Garcinia (Clusiaceae) in Thailand, pp. 175-211 in PhytoKeys 244 on pages 175-211, DOI: 10.3897/phytokeys.244.126207