''Pseuduvaria bruneiensis '' 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

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Borneo Borneo (; id, Kalimantan) is the third-largest island in the world and the largest in Asia. At the geographic centre of Maritime Southeast Asia, in relation to major Indonesian islands, it is located north of Java, west of Sulawesi, and eas ...

Yvonne Chuan Fang Su Yvonne Chuan Fang Su is a Hong Kong evolutionary biology, evolutionary biologist who is notable for her co-discovery of Pseuduvaria bruneiensis and Pseuduvaria borneensis. Her doctoral work at the University of Hong Kong focused on the Phylogenet ...

and

Richard M.K. Saunders Richard M. K. Saunders (born 1964) is a botanist. Work Among other subjects, his work has focused on the systematics and evolution of Annonaceae, a Family (biology), family of flowering plants. Legacy He is the authority for the followin ...

, the botanists who first formally described the species, named it after

Brunei Brunei ( , ), formally Brunei Darussalam ( ms, Negara Brunei Darussalam, Jawi alphabet, Jawi: , ), is a country located on the north coast of the island of Borneo in Southeast Asia. Apart from its South China Sea coast, it is completely sur ...

where the specimens they examined were collected.

Description

It is a tree reaching 6 meters in height. Its branches have sparse

lenticels 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 ...

. Its papery leaves are 12–18 by 4–6.5 centimeters and come to a point at their tips. The leaves are hairless on their upper and lower surfaces and except for the midrib which is densely hairy on the lower surface. The leaves have 12–16 pairs of secondary veins emanating from their midribs. Its hairy petioles are 5–10 millimeters long with a groove on their upper side.

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 organized on short, densely hairy peduncles, 1–1.5 millimeters in length. Each inflorescence has up to 6 flowers. 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 ...

10-13 millimeters in length. The flowers are unisexual. Its flowers have 3

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 ...

, 0.8–1 by 0.5 millimeters. The sepals are smooth on their upper surface, hairy on their lower surface, and have fine hairs on their margins. Its 6 petals are arranged in two rows of 3. The outer elliptical petals are 1.5 by 1–1.5 millimeters with smooth upper surfaces and densely hairy lower surfaces. The outer petals are cream-colored. The inner petals have a 0.7–1.2 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 2–2.5 by 2–2.5 millimeter blade. The cream-colored inner petals are smooth on their upper surface and densely hairy on their lower surface. Each inner petal has a crown-shaped gland at the base of its outer surface. Male flowers have up to 29

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 0.6 millimeters long. Female flowers have up to 7

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'' ...

per flower and 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 per carpel. Fruit are on pedicels 12–17 millimeters in length. The fruit consists of up to 3–6 monocarps. Each mature monocarp is a 6–8 by 6–8 millimeter globe. The mature monocarps have a distinctive equatorial ridge. The mature monocarps are green, have an irregular surface and are hairy. Each monocarp has around 2 seeds. The wrinkly, elliptical seeds are 7–7.5 by 6–6.5 millimeters.

Reproductive biology

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

References

External links

* Flora of Brunei Plants described in 2006 bruneiensis Taxa named by Yvonne Chuan Fang Su Taxa named by Richard M.K. Saunders {{annonaceae-stub