''Pseuduvaria fragrans'' is a species of

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

in the family Annonaceae. It is native to

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is bo ...

. Yvonne Su, Tanawat Chaowasku and Richard Saunders the botanists who first formally described the species, named it after its strongly fragrant (, in Latin) flowers.

Description

It is a tree reaching 4 meters in height. Its elliptical, papery to moderately leathery leaves are 8.5-15.5 by 2.5-6 centimeters. The leaves have pointed to blunt bases and tapering tips, with the tapering portion 9-18 millimeters long. The leaves are hairless on their upper and lower surfaces. The leaves have 8-14 pairs of secondary veins emanating from their midribs. Its hairless to slightly hairy petioles are 4-7 by 0.8-1.9 millimeters with a narrow groove on their upper side. Its

Inflorescences An inflorescence is a group or cluster of flowers arranged on a Plant stem, stem that is composed of a main branch or a complicated arrangement of branches. Morphology (biology), Morphologically, it is the modified part of the shoot of sperma ...

are solitary and are organized on peduncles that are 3.5-8 by 0.5 millimeters. Each inflorescence has up to 7 flowers. Each flower is on a sparsely hairy

pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

that is 3-10 by 0.2 millimeters. The pedicels have a medial, densely hairy

bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

that is 1 millimeters long. The flowers are unisexual. Its flowers have 3 oval

sepals A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

, that are 1-1.3 by 1-1.5 millimeters. The sepals are hairless on their upper surface, and densely hairy on their lower surface and margins. Its 6 petals are arranged in two rows of 3. The cream-colored, oval, outer petals are 3-4 by 3 millimeters with hairless upper surfaces and sparsely hairy lower surfaces. The inner petals are cream-colored with purple highlights on their upper surface. The diamond-shaped, inner petals have a 1.5-2.5 millimeter long claw at their base and a 4.5-5.5 by 3-3.5 millimeter blade. The inner petals have pointed tips and bases. The upper surfaces of the inner petals are densely hairy. The lower surfaces of the inner petals are sparsely hairy. The inner petals have a pair of smooth, round glands on their upper surface. Male flowers have up to 24 stamens that are 0.6 by 0.5 millimeters. Female flowers have up to 3

carpels Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' ...

that are 2.5 by 1 millimeters. Each carpel has 5

ovule In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (or remnant of the megasporangium), and the fe ...

s arranged in a single row. The fruit occur in clusters of 1-3 on hairless pedicles that are 13 by 1 millimeters. The pale green, mature fruit are elliptical and 25 by 3 millimeters with a tapering tip about 8 millimeters long. The fruit are smooth, and densely hairy.

Reproductive biology

The pollen of ''P. fragrans'' is shed as permanent tetrads.

Habitat and distribution

It has been observed growing in evergreen forests or limestone hills at elevations of 100 to 250 meters.

References

{{Taxonbar, from=Q17134934 fragrans Flora of Thailand Plants described in 2010 Taxa named by Yvonne Chuan Fang Su Taxa named by Richard M.K. Saunders