Mitrephora maingayi is a species of plant in the family Annonaceae. It is native to Bangladesh, Borneo, Cambodia, Laos, Peninsular Malaysia, Myanmar, Sumatra, and Vietnam. Joseph Hooker and Thomas Thomson, the British botanists who first formally described the species, named it in honor of Alexander Carroll Maingay, the British botanist who collected the specimen they examined.
It is a tree reaching in height. Its papery, oval to lance-shaped leaves are 5âÂÂ21.5 by 1.5âÂÂ9.6 centimeters. The leaves have pointed or short tapering tips and shallowly angled or rounded bases. The leaves, except for the midribs, are hairless and shiny on their upper surfaces and hairless or sparsely hairy on their undersides. The leaves have 5âÂÂ13 pairs of secondary veins emanating from their midribs. Its petioles are 5âÂÂ14 by 1âÂÂ3 millimeters. Its inflorescences are composed of up to 3 flowers positioned opposite from leaves. Each flower is born on a pedicel that is 10âÂÂ70 by 1 millimeters and densely covered in fine brown hairs. Oval bracts at the base of pedicels are 2âÂÂ4 by 1.5âÂÂ3 millimeters while middle bracts are 1.5âÂÂ4 by 1.4âÂÂ4 millimeters. Its oval sepals are 1.5âÂÂ4 by 2âÂÂ5.5 millimeters. The outer surfaces of the sepals have dense, brown hairs; the inner surfaces are hairless. Its flowers have 6 petals in two rows of three. The oval to elliptical outer petals are 10âÂÂ35 by 7âÂÂ17 millimeters with pointed tips and wavy margins when mature. The outer surfaces of the outer petals have pale hairs; the inner surfaces have short curly hairs near their tips. The outer petals are yellow with red highlights. The inner petals are 6âÂÂ13 by 3âÂÂ9 millimeters and yellow with red highlights. The inner petals have a 2 millimeter-wide basal claw below a heart-shaped blade. The outer surfaces of the inner petals are covered in short pale hairs; the inner surfaces are covered in long brown hairs near their tips. Its flowers have numerous oblong stamen that are 1 millimeter long. Its flowers have up to 10âÂÂ15 carpels that are 1 millimeter long. Its fruit are found in clusters of 5âÂÂ15. The round to elliptical, fruit are 1âÂÂ3 by 1âÂÂ2.5 centimeters. The fruit have dense, short pale hair and longer, sparser brown hairs. The fruit are born on 5âÂÂ30 by 1.5âÂÂ4 millimeter stipes that have dense, short pale hair and longer, sparser brown hairs. The stipes are attached to a pedicels that is 15âÂÂ40 by 3.5âÂÂ4 millimeters and sparsely covered in hairs. The fruit have 4âÂÂ8 seeds that are 6 by 10 millimeters.
Using the synonymous name, Mitrephora teysmannii, Yunyun Shao and Fengxia Xu report that the pollen of M. maingayi is shed as permanent tetrads.
It has been observed growing in lowlands or lower mountainous habitats at elevations up to .
Mitregenin, an acetogenin, has been isolated from its leaves and twigs. Several members of the acetogenin family of compounds have neurotoxic activity.