Pseuduvaria rugosa is a species of plant in the family Annonaceae. It is native to Java, Laos, the Lesser Sunda Islands, Peninsular Malaysia, Myanmar, the Nicobar Islands, Sumatra and Thailand. Carl Ludwig Blume, the botanist who first formally described the species under the basionym Uvaria rugosa, named it after its wrinkled ( in Latin) fruit.
It is a tree reaching in height. The young, dark brown to black branches are densely hairy but become hairless as they mature. Its elliptical to egg-shaped, papery to slightly leathery leaves are by . The leaves have pointed, wedge-shaped or blunt bases and tapering tips, with the tapering portion 6âÂÂ15 millimeters long. The leaves are hairless on their upper and lower surfaces. The leaves have 10âÂÂ18 pairs of secondary veins emanating from their midribs. Its sparsely to densely hairy petioles are 4âÂÂ12 by 0.8âÂÂ3 millimeters with a narrow groove on their upper side. Its Inflorescences occur in groups of 3âÂÂ6 on branches, and are organized on very densely hairy peduncles that are 1.5âÂÂ4 by 0.5âÂÂ0.7 millimeters. Each inflorescence has 1âÂÂ2 flowers. Each flower is on a very densely hairy pedicel that is 7âÂÂ24 by 0.3âÂÂ0.8 millimeters. The pedicels are organized on a rachis up to 5 millimeters long that have 3 bracts. The pedicels have a medial, very densely hairy bract that is 0.5âÂÂ1.5 millimeters long. Its flowers are unisexual. Its flowers have 3 free, triangular sepals that are 0.9âÂÂ1.5 by 0.8âÂÂ1.5 millimeters. The sepals are hairless on their upper surface, very densely hairy on their lower surface, and hairy at their margins. Its 6 petals are arranged in two rows of 3. The light yellow-green, oval to elliptical, outer petals are 1âÂÂ2.5 by 1âÂÂ2.5 millimeters with hairless upper and very densely hairy lower surfaces. The inner petals are red-purple to red-brown on their upper surfaces and light-yellow-green on their lower surfaces. The diamond-shaped inner petals have a 3âÂÂ7.5 millimeter long claw at their base and a 4âÂÂ10 by 2âÂÂ4 millimeter blade. The inner petals have pointed bases and tips. The inner petals are very densely hairy on their upper and lower surfaces. Male flowers have 30âÂÂ58 stamens that are 0.5âÂÂ0.8 by 0.4âÂÂ0.7 millimeters. Female flowers have 5âÂÂ13 carpels that are 1âÂÂ1.5 by 0.5âÂÂ0.8 millimeters. Each carpel has 2âÂÂ6 ovules arranged in two rows. Female flowers can have 4âÂÂ6 sterile stamens. The fruit occur in clusters of 1âÂÂ9 and are organized on densely hairy peduncles that are 3âÂÂ5 by 1âÂÂ2 millimeters. The fruit are attached by sparsely hairy pedicles that are 12âÂÂ27 by 0.8âÂÂ3 millimeters. The yellow-green to brown, globe-shaped fruit are 10âÂÂ20 by 10âÂÂ20 millimeters. The fruit are winkled, and very densely hairy. Each fruit has 2âÂÂ6 hemispherical to lens-shaped seeds that are 10âÂÂ14 by 5âÂÂ7.5 by 3.5âÂÂ5 millimeters. The seeds are wrinkled.
The pollen of P. rugosa is shed as permanent tetrads.
It has been observed growing on granite and limestone substrates in evergreen forests, dry ridge forests, or freshwater swamp forests, at elevations of .
Bioactive molecules extracted from its leaves and twigs have been reported to have cytostatic activity in tests with cultured human cancer cell lines.