Clethra
Encyclopedia
Clethra is a genus
of between 30-70 species
of flowering shrub
s or small tree
s. It is one of two genera in the family Clethraceae
(the other being Purdiaea
). The species may be evergreen
or deciduous
, and all bear flowers in clusters or inflorescences.
They are distributed from temperate
to tropical climates in eastern and southeastern Asia
, Malesia
, Central America
, northern South America
, the southeastern United States
, and one species (C. arborea) on the island of Madeira
.
Selected species
The number of species accepted varies between different authorities depending on taxonomic interpretation, but with a recent trend to reduce the number recognised as distinct; the recent Flora of China has cut the number accepted for China from 35 to 7 species, and the USDA only recognises two in the United States, synonymising C. tomentosa with C. alnifolia. The following is a selection:
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 between 30-70 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of flowering 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. It is one of two genera in the family Clethraceae
Clethraceae
Clethraceae is a small family of flowering plants in the order Ericales, native to warm temperate to tropical regions of Asia and the Americas, with one species also on Madeira...
(the other being Purdiaea
Purdiaea
Purdiaea is a genus of 11-19 species of flowering plants in the family Clethraceae. It is one of two genera in this family, and was formerly classified in the related family Cyrillaceae...
). The species may be evergreen
Evergreen
In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...
or 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...
, and all bear flowers in clusters or inflorescences.
They are distributed from temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
to tropical climates in eastern and southeastern 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...
, Malesia
Malesia
Malesia is a biogeographical region straddling the boundaries of the Indomalaya ecozone and Australasia ecozone, and also a phytogeographical floristic region in the Paleotropical Kingdom.-Floristic province:...
, Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
, northern South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, the southeastern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, and one species (C. arborea) on the island of Madeira
Madeira
Madeira is a Portuguese archipelago that lies between and , just under 400 km north of Tenerife, Canary Islands, in the north Atlantic Ocean and an outermost region of the European Union...
.
Selected species
The number of species accepted varies between different authorities depending on taxonomic interpretation, but with a recent trend to reduce the number recognised as distinct; the recent Flora of China has cut the number accepted for China from 35 to 7 species, and the USDA only recognises two in the United States, synonymising C. tomentosa with C. alnifolia. The following is a selection:
- Clethra acuminata Michx. – Mountain Pepper Bush; southeastern United States.
- Clethra alnifoliaClethra alnifoliaClethra alnifolia , is a flowering plant in the genus Clethra, native to eastern North America from southern Nova Scotia and Maine south to northern Florida, and west to eastern Texas....
L. – Sweet Pepper Bush; eastern United States. - Clethra arboreaClethra arboreaClethra arborea, commonly known as the Lily of the Valley Tree, is a flowering plant in the genus Clethra. It is found in Macaronesia where it is native to Madeira, extinct in the Canary Islands, and considered an introduced species in the Azores...
Ait. – Lily of the Valley Tree; Madeira (considered extinct in the Canary islandsCanary IslandsThe Canary Islands , also known as the Canaries , is a Spanish archipelago located just off the northwest coast of mainland Africa, 100 km west of the border between Morocco and the Western Sahara. The Canaries are a Spanish autonomous community and an outermost region of the European Union...
, also present in the AzoresAzoresThe Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about west from Lisbon and about east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the...
). - Clethra barbinervis Siebold & Zucc. – Japanese Sweet Shrub; eastern China, Korea, Japan.
- Clethra bodinieri – southern China.
- Clethra brasiliensis – northeastern South America.
- Clethra crispa – northwestern South America.
- Clethra delavayi – southern China to Bhutan and Vietnam.
- Clethra fabri – southern China, Vietnam.
- Clethra fargesii – central China.
- Clethra fimbriata – northwestern South America.
- Clethra kaipoensis – southeastern China.
- Clethra lanata – southern Mexico to Panama.
- Clethra mexicana – southern Mexico, Central America.
- Clethra obovata – northwestern South America.
- Clethra ovalifolia – northwestern South America.
- Clethra paralelinervia – northwestern South America.
- Clethra petelotii – Vietnam, Yunnan.
- Clethra pringlei - Mexican Summersweet; northeastern Mexico.
- Clethra revoluta – northwestern South America.
- Clethra rugosa – northwestern South America.
- Clethra scabra – northeastern South America .