Pterostyrax is a small genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of four species of deciduous

Deciduous

Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...

 large shrub

Shrub

A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

s or small tree

Tree

A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

s in the family Styracaceae

Styracaceae

Styracaceae is a small family of flowering plants in the order Ericales, containing 11 genera and about 160 species of trees and shrubs. The family occurs in warm temperate and subtropical regions of the Northern Hemisphere....

, native to eastern Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

 in China

China

Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 and Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

. They grow to 4-12 m tall, and have alternate, simple ovate leaves

Leaf

A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 6-17 cm long and 4-10 cm broad. The flower

Flower

A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

s are white, produced in dense panicle

Panicle

A panicle is a compound raceme, a loose, much-branched indeterminate inflorescence with pedicellate flowers attached along the secondary branches; in other words, a branched cluster of flowers in which the branches are racemes....

s 8-25 cm long. The fruit

Fruit

In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

 is an oblong dry drupe

Drupe

In botany, a drupe is a fruit in which an outer fleshy part surrounds a shell of hardened endocarp with a seed inside. These fruits develop from a single carpel, and mostly from flowers with superior ovaries...

, with longitudinal ribs or narrow wings (the wings are absent in the related genus Styrax

Styrax

Styrax is a genus of about 130 species of large shrubs or small trees in the family Styracaceae, mostly native to warm temperate to tropical regions of the Northern Hemisphere, with the majority in eastern and southeastern Asia, but also crossing the equator in South America...

, whence the name Pterostyrax, "winged styrax").

Species

• Pterostyrax burmanicus W.Wsm.
• Pterostyrax corymbosus Siebold & Zucc. - Japan and China
• Pterostyrax hispidus - Japan
• Pterostyrax psilophyllus
  Pterostyrax psilophyllus
  Pterostyrax psilophyllus is a species of flowering plant in the family Styracaceae. It is endemic to central China. It is threatened by habitat loss....
  
  Diels ex Perkins - China

The species names are frequently given with feminine gender ("corymbosa", etc); however, the genus is correctly of masculine gender.