''Pseuduvaria cymosa'' is a species of

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

in the family

Annonaceae The Annonaceae are a Family (biology), family of flowering plants consisting of trees, shrubs, or rarely lianas commonly known as the custard apple family or soursop family. With 108 accepted genera and about 2400 known species, it is the largest ...

. It is native to

Peninsular Malaysia Peninsular Malaysia, historically known as Malaya and also known as West Malaysia or the Malaysian Peninsula, is the western part of Malaysia that comprises the southern part of the Malay Peninsula on Mainland Southeast Asia and the list of isla ...

. James Sinclair, the Scottish botanist who first

formally described A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...

the species using the synonym ''Pseuduvaria macrophylla'' var. ''cymosa'', named it after its branched inflorescences which are called

cymes In botany, an inflorescence is a group or cluster of flowers arranged on a plant's stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a main axis ( ped ...

Description

It is a tree reaching 18 meters in height. Its elliptical, moderately leathery leaves are 14.5-23 by 4-10 centimeters. The leaves have blunt bases and tapering tips, with the tapering portion 6-14 millimeters long. The leaves are hairless on their upper and lower surfaces except for the midrib which can be sparsely hairy. The leaves have 14-18 pairs of secondary veins emanating from their midribs. Its densely hairy petioles are 5–9 by 1.5-3 millimeters with a broad groove on their upper side. Its

Inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

s are solitary or occur in pairs and are organized on 2-4 millimeter-long, densely hairy peduncles. Each inflorescence has up to 4 flower. Each flower is on a densely 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 5–15 by 0.5-0.9 millimeters. The pedicels are organized on a

rachis In biology, a rachis (from the [], "backbone, spine") is a main axis or "shaft". In zoology and microbiology In vertebrates, ''rachis'' can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the ''rachi ...

up to 5 millimeters long. The flowering pedicels have a medial, densely hairy

bract In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also lo ...

that is 0.5-1 millimeters long. The flowers are unisexual. Its flowers have 3 triangular

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 Etymology The term ''sepalum'' ...

, that are 1.5 by 1.5-2.5 millimeters. The sepals are hairless on their upper surface, and sparsely hairy on their lower surface. Its 6 petals are arranged in two rows of 3. The red to yellowish-purple, oval, outer petals are 2-2.5 by 2.5-3.5 millimeters with hairless upper surfaces and densely hairy lower surfaces. The red to yellowish-purple, triangular, inner petals have a 1.5-3 millimeter long

claw A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or Arthro ...

at their base and a 4-6.5 by 3-3.5 millimeter blade. The inner petals have pointed tips and wedge-shaped bases. The upper and lower surfaces of the inner petals are mostly hairless. There is a solitary, smooth, elliptical gland on the upper surface of the inner petals.Male flowers have up to 65

stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s that are 0.8-1 by 0.5 millimeters. Female flowers have up to 13

carpels Gynoecium (; ; : gynoecia) 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) ...

that are 1.6-1.8 by 0.8-0.9 millimeters. Each carpel has 4

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 sporangium, megasporangium), ...

s arranged in a single row. The female flowers have up to 9 sterile stamen.The fruit occur in clusters of 1-8 and are on sparsely hairy pedicles that are 15–30 by 1-3 millimeters. The mature fruit are round and 5–16 by 5-15 millimeters. The mature, smooth, densely hairy fruit have a sharp point that is 0.3-0.4 millimeters long. Each fruit has up to 2 seeds. The wrinkled, spherical seeds are 9-9.5 by 8.5 by 4.5-5.5 millimeters.

Reproductive biology

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

Habitat and distribution

It has been observed growing near streams.

References

{{Taxonbar, from=Q17134830 cymosa Flora of Peninsular Malaysia Plants described in 1855 Taxa named by James Sinclair (botanist) Taxa named by Yvonne Chuan Fang Su Taxa named by Richard M.K. Saunders