Pseuduvaria rugosa is a species of plant in the family Annonaceae.[1] It is native to Java, Laos, the Lesser Sunda Islands, Peninsular Malaysia, Myanmar, the Nicobar Islands, Sumatra and Thailand.[2] Carl Ludwig Blume, the botanist who first formally described the species under the basionym Uvaria rugosa, named it after its wrinkled (Latin: rugosus in Latin) fruit.[3] [4]
It is a tree reaching 40 meters 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 10-23 by 3–8.5 centimeters. The leaves have pointed, wedge-shaped or blunt bases and tapering tips, with the tapering portion 6-15 millimeters long. The leaves are hairless on their upper and lower surfaces. The leaves have 10-18 pairs of secondary veins emanating from their midribs. Its sparsely to densely hairy petioles are 4-12 by 0.8-3 millimeters with a narrow groove on their upper side. Its Inflorescences occur in groups of 3–6 on branches, and are organized on very densely hairy peduncles that are 1.5-4 by 0.5-0.7 millimeters. Each inflorescence has 1-2 flowers. Each flower is on a very densely hairy pedicel that is 7-24 by 0.3-0.8 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 0.5-1.5 millimeters long. Its flowers are unisexual. Its flowers have 3 free, triangular sepals that are 0.9-1.5 by 0.8-1.5 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 1–2.5 by 1–2.5 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 3–7.5 millimeter long claw at their base and a 4-10 by 2-4 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 30-58 stamens that are 0.5-0.8 by 0.4-0.7 millimeters. Female flowers have 5-13 carpels that are 1-1.5 by 0.5-0.8 millimeters. Each carpel has 2-6 ovules arranged in two rows. Female flowers can have 4-6 sterile stamens. The fruit occur in clusters of 1-9 and are organized on densely hairy peduncles that are 3-5 by 1-2 millimeters. The fruit are attached by sparsely hairy pedicles that are 12-27 by 0.8-3 millimeters. The yellow-green to brown, globe-shaped fruit are 10-20 by 10-20 millimeters. The fruit are winkled, and very densely hairy. Each fruit has 2-6 hemispherical to lens-shaped seeds that are 10-14 by 5–7.5 by 3.5-5 millimeters. The seeds are wrinkled.[5]
The pollen of P. rugosa is shed as permanent tetrads.[6] [7]
It has been observed growing on granite and limestone substrates in evergreen forests, dry ridge forests, or freshwater swamp forests, at elevations of 100–450 meters.[5]
Bioactive molecules extracted from its leaves and twigs have been reported to have cytostatic activity in tests with cultured human cancer cell lines.[8]