Clethra

Clethra is a genus of flowering shrubs or small trees described as a genus by Linnaeus in 1753.
Clethra 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 (inflorescences), which correspond to racemes or panicles. The flowers are quite small, white or pinkish, and each bear 5 free petals, numerous stamens, and a 3-chambered seed capsule. The leaves, simple, ovate, and alternate or opposite, bear characteristic stellate hairs. The seeds are very small and numerous.
Distribution
Clethra species are native to a variety of habitats, including swamps, woodland, and rocky sites from temperate to tropical climates in eastern and southeastern Asia, Malesia, North and South America, and one species (C. arborea) on the island of Madeira.
Fossil record
Several fossil fruits and seeds of †Clethra cimbrica have been described from middle Miocene strata of the Fasterholt area near Silkeborg in Central Jutland, Denmark.
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 (series) has cut the number accepted for China from 35 to seven species, and the US Department of Agriculture recognises only two in the United States, synonymising C. tomentosa with C. alnifolia. The following are accepted by the World Checklist of Selected Plant Families:
Clethra acuminata – mountain pepper bush; S Appalachians (Alabama to Pennsylvania)
Clethra alcoceri - Hidalgo, Jalisco
Clethra alexandri - Jamaica
Clethra alnifolia – sweet pepper bush; S + E United States (Texas to Maine)
Clethra arborea – lily of the valley tree; Madeira, Canary islands†, Azores
Clethra arfakana - New Guinea
Clethra barbinervis – Japanese sweet shrub; SE China, Korea, Japan
Clethra bodinieri – S China
Clethra canescens - Philippines, E + C Indonesia, New Guinea
var. clementis – Borneo
Clethra castaneifolia - Peru
Clethra chiapensis - Chiapas
Clethra consimilis - Panama, Costa Rica
Clethra conzattiana - Oaxaca
Clethra crispa – Ecuador
Clethra cubensis - Cuba
Clethra cuneata - Peru, Bolivia
Clethra delavayi – SW China, Assam, Myanmar, Bhutan, Vietnam
Clethra elongata - Peru, Bolivia
Clethra fabri – S China, Vietnam
Clethra fagifolia - Ecuador, Colombia, Venezuela
Clethra fargesii – C China
Clethra ferruginea - Peru
Clethra fimbriata – Peru, Ecuador, Colombia
Clethra formosa - Costa Rica
Clethra fragrans - Jalisco, Michoacán, Guerrero
Clethra galeottiana - Puebla, Oaxaca, Chiapas
Clethra gelida - Costa Rica, Panama, Honduras
Clethra guyanensis - Guyana, Venezuela
Clethra hartwegii - C + S Mexico
Clethra hendersonii - Peninsular Malaysia
Clethra hirsutovillosa - Guerrero
Clethra hondurensis - Tabasco to Costa Rica
Clethra javanica - Java, Bali, Lombok, Timor
Clethra kaipoensis – SE China
Clethra kebarensis - New Guinea
Clethra licanioides – Guatemala, Honduras
Clethra longispicata – Borneo, Philippines, Sulawesi, Maluku
Clethra luzmariae - Oaxaca
Clethra macrophylla - Veracruz, Puebla
Clethra mexicana – C + S Mexico, Central America, Colombia, Venezuela, Trinidad
Clethra oaxacana - Oaxaca
Clethra obovata – Ecuador, Peru
Clethra occidentalis - Jamaica
Clethra oleoides - C + S Mexico, Central America
Clethra ovalifolia – Colombia, Venezuela, Ecuador, Peru
Clethra pachecoana - Chiapas to Honduras
Clethra pachyphylla – Borneo
Clethra papuana - New Guinea
Clethra paralelinervia – Ecuador
Clethra × parvifolia - Chiapas
Clethra pedicellaris - Colombia, Ecuador, Peru
Clethra peruviana - Ecuador, Peru
Clethra petelotii – Vietnam, Yunnan
Clethra poilanei - Laos
Clethra pringlei - Mexican summersweet - Mexico
Clethra pulgarensis - Palawan
Clethra purpusii - Oaxaca, Chiapas
Clethra pyrogena - Panama, Costa Rica
Clethra repanda – Colombia, Venezuela
Clethra retivenia - Peru
Clethra revoluta – Colombia, Bolivia, Ecuador, Peru
Clethra rosei - Mexico
Clethra rugosa – Colombia, Ecuador
Clethra scabra – Brazil, Bolivia, Paraguay, NW Argentina
Clethra skutchii - Guatemala
Clethra sleumeriana - Hunan
Clethra suaveolens - S Mexico, Central America
Clethra sumatrana - Sumatra
Clethra sumbawaensis - Lesser Sunda Islands
Clethra symingtonii - Perak
Clethra talamancana - Costa Rica
Clethra tomentella - Philippines
Clethra tutensis - Panama
Clethra tuxtlensis - Veracruz
Clethra uleana - S Brazil
Clethra vicentina - S Mexico, Central America
References
External links
Ericales genera
Taxa named by Carl Linnaeus