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Hoya (plant)

From Wikipedia, the free encyclopedia

Hoya
Hoya lanceolata subsp. bella
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Gentianales
Family: Apocynaceae
Subfamily: Asclepiadoideae
Tribe: Marsdenieae
Genus: Hoya
R.Br.[1]
Species

See List of Hoya species

Synonyms[1]
Hoya carnosa
Hoya mindorensis, Sydney, Australia.

Hoya is a genus of over 500 species of plants in the dogbane family, Apocynaceae, commonly known as waxflowers.[2] Plants in the genus Hoya are mostly epithytic or lithophytic vines, rarely subshrubs, with leathery, fleshy or succulent leaves, shortly tube-shaped or bell-shaped flowers with five horizontally spreading lobes, the flowers in umbels or racemes, and spindle-shaped or cylindrical to oval follicles containing flattened egg-shaped to oblong seeds.[2][3][4]

Description

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Plants in the genus Hoya are mostly epithytic or lithophytic vines that rarely form roots in the ground, or rarely more or less shrubby. They have creeping or climbing, pendent, left-twining stems, with white latex, and sometimes with adventitious roots. The stems are cylindrical in cross section, and more or less sparsely branched. The leaves are leathery, often fleshy or succulent, elliptic, egg-shaped, rhomboid or lance-shaped, may be glabrous or hairy, and usually have a petiole.[2][3][4][5][6]

The flowers are often fleshy or waxy, arranged in umbels or racemes on a peduncle between the leaves, the peduncle usually persisting from year to year. The petals are wheel-shaped or tube-shaped, with five fleshy, more or less jug-shaped, horizontally spreading lobes attached to the staminal column, and forming a prominent ring alternating with the petal lobes.[2][3][4][5][6]

The fruit is a spindle-shaped to oval follicle containing flattened, egg-shaped to oblong seeds with a tuft of hairs at one end.[2][4][5]

Taxonomy

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The genus was first formally described in 1810 by botanist Robert Brown in his book Prodromus Florae Novae Hollandiae et Insulae Van Diemen,[7] and honours Thomas Hoy, the gardener for the Duke of Northumberland.[2] The first species of Hoya that Brown described (the type species), was Hoya carnosa.[7]

Species list

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Use in horticulture

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Many species of Hoya are popular houseplants in temperate areas (especially H. carnosa), grown for their attractive foliage and strongly scented flowers. Numerous cultivars have been selected for different leaf forms or flower colours. Hoyas grow well indoors, preferring bright light, but will tolerate fairly low light levels, although they may not flower without bright light. Hoyas commonly sold in nurseries as houseplants include cultivars of H. carnosa (Krimson Queen, Hindu Rope − compacta), H. pubicalyx (often mislabelled as H. carnosa or H. purpurea-fusca), and H. kerrii. Hoyas are easy to propagate, and are commonly sold as cuttings, either rooted or unrooted, or as a potted plant.[citation needed]

Hoya carnosa has been shown in recent studies at the University of Georgia to be an excellent remover of pollutants in the indoor environment.[8]

Various cultures have used hoyas medicinally, especially Polynesian cultures.[citation needed] Some are toxic to livestock and sheep poisonings in Australia are reported.[citation needed]

Several Hoya species and cultivars are excellent terrarium plants.[citation needed]

Rachel Colette Conroy was appointed the International Cultivar Registration Authority for Hoya in 2023.[9]

References

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  1. ^ a b "Hoya". Plants of the World Online. Retrieved 27 November 2024.
  2. ^ a b c d e f Forster, Paul Irwin; Liddle, David J. "Hoya". Flora of Australia. Australian Biological Resources Study, Department of Climate Change, Energy, the Environment and Water: Canberra. Retrieved 27 November 2024.
  3. ^ a b c Harden, Gwen J.; Williams, John B. "Genus Hoya". Royal Botanic Garden, Sydney. Retrieved 27 November 2024.
  4. ^ a b c d "Hoya". Northern Territory Government. Retrieved 27 November 2024.
  5. ^ a b c Albers, Focke; Meve, Ulrich, eds. (2004). Illustrated Handbook of Succulent Plants. Vol. 4. Berlin: Springer-Verlag. pp. 147–148. ISBN 978-3-540-41964-8. Retrieved 29 November 2024.
  6. ^ a b "Hoya". FloraBase. Western Australian Government Department of Biodiversity, Conservation and Attractions.
  7. ^ a b Brown, Robert (1810). Prodromus Florae Novae Hollandiae et Insulae Van Diemen. London: Typis R Taylor, veneunt apud J. Johnson. pp. 459–460. Retrieved 27 November 2024.
  8. ^ "UGA research shows some plants can remove indoor pollutants". University of Georgia. UGA Today. 31 March 2009. Retrieved 27 November 2024.
  9. ^ "ICRA Report Sheet". International Society for Horticultural Science. Retrieved 12 October 2023.

Bibliography

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