It is a tree reaching 22 meters in height. The young, yellow to gray-brown branches are slightly to densely hairy and also have sparse lenticels. Its egg-shaped to elliptical, slightly leathery to leathery leaves are 9-20 by 3–7.5 centimeters. The leaves have pointed to blunt bases and tapering tips, with the tapering portion 8-24 millimeters long. The leaves are hairless on their upper and lower surfaces. The leaves have 10-16 pairs of secondary veins emanating from their midribs. Its sparsely to very densely hairy petioles are 4-13 by 1–2.5 millimeters with a broad groove on their upper side. Its Inflorescences occur in groups of 2–7 on branches, and are organized on indistinct peduncles. Each inflorescence has 1-2 flowers. Each flower is on a densely hairy pedicel that is 4-11 by 0.3-0.7 millimeters. The pedicels are organized on a rachis up to 5 millimeters long that have 2 bracts. The pedicels have a medial, sparsely hairy bract that is 0.2-1 millimeters long. Its flowers are unisexual. Its flowers have 3 free, oval sepals, that are 0.5-1.5 by 0.7-2 millimeters. The sepals are hairless on their upper surface, sparsely to densely hairy on their lower surface, and hairy at their margins. Its 6 petals are arranged in two rows of 3. The white to yellow, oval, outer petals are 1-2 by 1-2 millimeters with hairless upper and densely hairy lower surfaces. The white to yellow, heart-shaped to diamond-shaped, inner petals have a 2-7 millimeter long claw at their base and a 4-10 by 2-5 millimeter blade. The tips of the male flowers have two concave sides while those of the female flowers are pointed. The bases of the male flowers are heart-shaped to flat while those of the female flowers are flat. The inner petals are densely hairy on their upper and lower surfaces. Male flowers have 30-45 stamens that are 0.5-0.8 by 0.4-0.6 millimeters. Female flowers have 6-7 carpels that are 1.4-1.6 by 0.6-0.9 millimeters. Each carpel has 3-5 ovules arranged in two rows. The female flowers have up to 6 sterile stamens. The fruit occur in clusters of 1–5 on sparsely to densely hairy pedicles that are 9-13 by 1–2.5 millimeters. The brown, globe-shaped fruit are 12-21 by 11-18 millimeters. The fruit are smooth, and very densely hairy. Each fruit has 3-5 hemispherical to lens-shaped seeds that are 9–11.5 by 6.5-9 by 2- millimeters. The seeds are wrinkly.[5]
Reproductive biology
The pollen of P. pamattonis is shed as permanent tetrads.[6]
Habitat and distribution
It has been observed growing in limestone and clay soils in lowland and mountain forests at elevations of 70–670 meters.[5]
^ abSu, Yvonne C.F.; Saunders, Richard M.K. (2006). Monograph of Pseuduvaria (Annonaceae). Systematic Botany Monographs. Vol. 79. American Society of Plant Taxonomists. pp. 1–204. JSTOR25027955.
