Nesohedyotis

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St Helena dogwood
MELLISS(1875) p371 - PLATE 35 - Hedyotis Arborea.jpg
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Gentianales
Family: Rubiaceae
Subfamily: Rubioideae
Tribe: Spermacoceae
Genus: Nesohedyotis
(Hook.f.) Bremek.
Species:
N. arborea
Binomial name
Nesohedyotis arborea
(Roxb.) Bremek.

Nesohedyotis is a genus of flowering plants endemic to the island of Saint Helena in the South Atlantic Ocean. It in the family Rubiaceae (the family that includes coffee).

Contents

It is a monotypic genus containing the single species Nesohedyotis arborea (Roxb.) Bremek., which grows on the central ridge of the island. It is known commonly as the St. Helena dogwood. [1] The vernacular name recalls the similarity between its inflorescences and those of Cornus species, the dogwoods of Europe and North America. [2] Although it is one of the commoner endemic species on Saint Helena its small population size and small geographical distribution make it endangered.

This species is a small, erect tree growing up to 7 meters tall. The leaves are oppositely arranged. They are lance-shaped with a pointed, downcurved "drip tip". The white flowers are 3 or 4 millimeters wide and the fruit is a brown or black capsule. [2]

This tree is a keystone species in the thickets of the island. The leaves collect mist, which condenses and falls from the "drip tips" into the vegetation below, providing water. [2]

See also

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<i>Dicksonia arborescens</i> Species of fern

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<i>Trochetiopsis ebenus</i> Species of flowering plant

Trochetiopsis ebenus, the dwarf ebony or Saint Helena ebony, is a species of flowering plant that is endemic to the island of Saint Helena in the southern Atlantic Ocean. It is not related to the ebony of commerce, but is instead a member of the mallow family, Malvaceae. Saint Helena ebony is now critically endangered in the wild, being reduced to two wild individuals on a cliff, but old roots are sometimes found washed out of eroding slopes. These are collected on the island a used for inlay work, an important craft on Saint Helena. A related species, Trochetiopsis melanoxylon is now completely extinct.

<i>Wahlenbergia roxburghii</i> Extinct species of flowering plant

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<i>Trochetiopsis melanoxylon</i> Extinct species of flowering plant

Trochetiopsis melanoxylon, the dwarf ebony or St Helena ebony, of the island of Saint Helena is related to Trochetiopsis ebenus but is now extinct. It differed from T. ebenus by having much smaller flowers, sepals hairless on their interior surfaces and leaves densely hairy on both surfaces.

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<i>Commidendrum robustum</i> Species of flowering plant

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<i>Trimeris</i> Genus of flowering plants

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<i>Mellissia</i> Genus of flowering plants

Mellissia was formerly a monotypic genus in the family Solanaceae with the single species, Mellissia begoniifolia, , endemic to the island of Saint Helena. It was named by Joseph Dalton Hooker in honour of John Charles Melliss, a 19th-century engineer and amateur naturalist who worked on Saint Helena. The plant is now known correctly as Withania begoniifolia (Roxb.) Hunz. & Barboza, the genus Mellissia having been subsumed in the genus Withania.

<i>Banksia arborea</i> Species of plant in the family Proteaceae native to Western Australia

Banksia arborea, commonly known as Yilgarn dryandra, is a species of tree that is endemic to Western Australia. It has serrated, sharply pointed leaves, and yellow flowers and is found inland north of Southern Cross.

<i>Cinchona pubescens</i> Species of plant

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<i>Anogramma ascensionis</i> Species of fern

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References

  1. 1 2 Cairns-Wicks, R. 2003. Nesohedyotis arborea. The IUCN Red List of Threatened Species 2003. Downloaded on 24 November 2015.
  2. 1 2 3 Percy, D. M., & Cronk, Q. C. B. (1997). Conservation in relation to mating system in Nesohedyotis arborea (Rubiaceae), a rare endemic tree from St Helena. Biological Conservation, 80(2), 135-145.

Further reading