''Pseuduvaria glabrescens'' 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 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

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. L.W. Jessup, the botanist who first formally described the species using the synonym ''Pseuduvaria mulgraveana'' var. ''glabrescens'', named it after the underside of its leaves which have the quality of becoming hairless ( in Latin) as they mature.

Description

It is a tree reaching 9 meters in height. Its young, dark brown to black branches are sparsely hairy but turn hairless. The young branches are also densely covered in

lenticel A lenticel is a porous tissue consisting of cells with large intercellular spaces in the periderm of the secondarily thickened organs and the bark of woody stems and roots of dicotyledonous flowering plants. It functions as a pore, providing a ...

s. Its elliptical to oval, membranous to papery leaves are 7–16.5 by 2–6.5 centimeters. The leaves have rounded bases and tapering tips, with the tapering portion 3-16 millimeters long. The leaves are hairless on their upper surface. The undersides of the leaves are sparsely hairy but become hairless. The leaves have 8-12 pairs of secondary veins emanating from their midribs. Its sparsely hairy petioles are 1.5-6 by 0.6-2.5 millimeters with a broad groove on their upper side. Its

Inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

s are solitary and are organized on indistinct peduncles. Each inflorescence has a solitary flower. Each flower is on a hairless to slightly 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 17-50 by 0.2-1.2 millimeters. The pedicels have a medial, hairless to slightly 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 0.5-1.2 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 1-2 by 1-1.5 millimeters. The sepals are hairless on their upper surface and margins, and hairless to slightly hairy on their lower surface. Its 6 petals are arranged in two rows of 3. The cream-colored, oval to egg-shaped, outer petals are 3.5-6 by 2.5-6.5 millimeters with hairless upper surfaces and sparsely hairy lower surfaces. The inner petals are cream-colored with pink to purple highlights near their edges. The diamond-shaped, inner petals have a 1.5-3.5 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 tarsus ...

at their base and a 6.5-8 by 4.5-7 millimeter blade. The inner petals have pointed bases and tips that form a right angle. The upper surfaces of the inner petals are sparsely hairy except near their tips where the hairs are denser. The lower surfaces of the inner petals are sparsely hairy. The inner petals have a pair of prominent, smooth, elliptical glands on their upper surface. Male flowers have up to 70-80

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

s that are 0.9-1 by 0.6-0.9 millimeters. Female flowers have up to 22-29

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 1.5-2 by 0.5-0.9 millimeters. Each carpel has 1-2

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. Female flowers also have 6-17 sterile stamen. The fruit occur in clusters of 3–18 on hairless pedicles that are 38-55 by 0.7-2 millimeters. The orange, mature fruit are elliptical to globe-shaped and 7-16 by 6-12 millimeters with a tapering tip about 0.5-0.8 millimeters long. The fruit are smooth, and densely hairy. Each fruit has 2 spherical seeds that are 8–9.5 by 7.5-9 by 5-7 millimeters. The seeds are wrinkly.

Reproductive biology

The pollen of ''P. glabrescens'' is shed as permanent tetrads. Its flowers are pollinated by flies.

Habitat and distribution

It has been observed growing in rocky or clay soil types in vine forests at elevations of 100–820 meters.

Uses

Oils extracted from its leaves contain high levels of

elemicin Elemicin is a phenylpropene, a natural organic compound, and is a constituent of several plant species' essential oils. Natural occurrence Elemicin is a constituent of the oleoresin and the essential oil of ''Canarium luzonicum'' (also referred ...

and

methyl eugenol Methyl eugenol (allylveratrol) is a natural chemical compound classified as a phenylpropene, a type of phenylpropanoid. It is the methyl ether of eugenol and is important to insect behavior and pollination. It is found in various essential oils. ...

References

{{Taxonbar, from=Q17135067 glabrescens Flora of Queensland Endemic flora of Australia Plants described in 1987 Taxa named by Yvonne Chuan Fang Su Taxa named by Richard M.K. Saunders