Hoya

Cladus: Eukaryota
Regnum: Plantae
Divisio: Magnoliophyta
Classis: Magnoliopsida
Ordo: Gentianales
Familia: Apocynaceae
Subfamilia: Asclepiadoideae
Tribus: Marsdenieae
Genus: Hoya
Sectiones: H. sect. Acanthostemma - H. sect. Amblyostemma - H. sect. Angustialatus - H. sect. Angusticarinatae - H. sect. Antiostelma - H. sect. Centrostemma - H. sect. Cystidianthus - H. sect. Eriostemma - H. sect. Hoya - H. sect. Kloiphora - H. sect. Latiretinacula - H. sect. Oreostemma - H. sect. Otostemma - H. sect. Pachystelma - H. sect. Peltostemma - H. sect. Physostemma - H. sect. Plocostemma - H. sect. Pterostelma - H. sect. Unassigned
Species: H. australis - H. camphorifolia - H. campanulata - H. carnosa - H. cinnamomifolia - H. fraterna - H. globulosa - H. imbricata - H. imperialis - H. keysii - H. lanceolata - H. lasiantha - H. longifolia - H. macgillivrayi - H. multiflora - H. obovata - H. purpureofusca - H. ridleyi - H. solaniflora

Name

Hoya R.Br.

Typus: H. carnosa (L.) R. Br.

Synonyms

Heterotypic

* Acanthostemma (Blume) Blume in Rumphia 4: 29. Oct (sero) 1849.
* Absolmsia Kuntze, Rev. Gen. Pl. 2: 417. 5 Nov 1891.
* Antiostelma (Tsiang & P. T. Li) P. T. Li in Novon 2: 218. 1992.
* Centrostemma Decne. in Ann. Sci. Nat. Bot., s 2,9: 271. Mai 1838.
* Cyrtoceras Bennett, Pl. Jav. Rar.: 90. t. 21. 4-7 Jul 1838.
* Cystidianthus Hassk., Cat. Hort. Bot. Bogor.: 126. 1844.
* Madangia P.I.Forst., Liddle & I.M.Liddle, Austrobaileya 5: 54. 1997.
* Micholitzia N.E.Br. in Bull. Misc. Inform. 1909: 358. Oct 1909.
* Otostemma Blume in Mus. Bot. 1: 59. Nov (?) 1849.
* Physostelma Wight, Contr. Bot. India: 39. Dec 1834.
* Plocostemma Blume in Mus. Bot. 1: 59. Nov 1849.
* Pterostelma Wight, Contr. Bot. India: 39. Dec 1834.
* Schollia Jacq., Eclog. Pl. Rar. 1: 5. Oct 1811.
* Sperlingia Vahl Skr. Naturhist.-Selsk. 6: 112. 1810.

References

Wanntorp, L., Kocyan, A., van Donkelaar, R. & Renner, S.S. (2006) Towards a Monophyletic Hoya (Marsdenieae, Apocynaceae): Inferences from the Chloroplast trnL Region and the rbcL-atpB Spacer. Systematic Botany 31(3):586-596.

Vernacular name
Türkçe: Mum çiçeği

Hoya is a genus of 200-300 species of tropical climbing plants in the family Apocynaceae (Dogbane), native to southern Asia (India east to southern China and southward), Australia, and Polynesia. Common names for this genus are waxplant, waxvine, waxflower or simply hoya. This genus was named by botanist Robert Brown, in honour of his friend, botanist Thomas Hoy.

Summary

Hoyas are evergreen climbing vines or shrubs growing to 1-10 m (or more with suitable support in trees). They have simple opposite leaves 5-30 cm long that are typically succulent, and in many species are flecked with irregular small silvery spots.

The flowers appear in axillary umbellate clusters at the apex of 2-3 cm peduncles, with repeated clusters of flowers developing sequentially on each peduncle. The flowering peduncles get 2-3 mm longer with each flowering, and can eventually reach 7 cm or more long; the base of the peduncle is smooth, with growth subsequent to the first flowering of the peduncle is rough with numerous tiny bracts. Each flower is about 1 cm diameter, with five thick, waxy, triangular petals; colours range from white to pink or yellow. They are sweetly scented and produce abundant nectar.

Cultivation and uses

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 garden use. Hoyas grow well indoors, preferring bright but not direct sunlight, but will tolerate fairly low light levels at the expense of rapid growth and blooming. Hoyas commonly sold in nurseries as houseplants include cultivars of H. carnosa (Krimson Queen, Hindu Rope − compacta), H. pubicalyx (often mislabeled as carnosa), and H. kerrii. Hoyas are easy to purchase on the internet, and are commonly sold as cuttings, either rooted or unrooted.

Leaves

Hoya leaves vary in size, texture, color and venation. In size, leaves range from as small as centimetre in length and from two to four millimetres in width (Hoya engleriana Hosseus) to as large as 25 cm. by 25 cm. (Hoya latifolia G. Don). Hoya coriacea Blume, has been reported have leaves as long as two feet in length. One of the most succulent, Hoya kerrii Craib, has valentine shaped leaves, with notches at the apexes of the leaves instead of at the bases. H. kerrii has two forms, one with glabrous leaves and one with suede textured leaves. There are hoyas with almost perfectly round leaves and others with linear leaves (Hoya linearis Wall. ex. D. Don and Hoya teretifolia Griff. ex Hook. f.). One popular species, Hoya shepherdii Short ex Hook. has leaves that resemble string beans hanging in bunches from their stalks. Hoya linearis Wall. ex D. Don is covered with fine downy hair and greatly resembles masses of Spanish Moss (Tillandsia useneoides) hanging from trees in its native habitat. Some Hoya leaves are smooth and shiny; some are covered with hairs. Some Hoya leaves appear to be veinless while others have very conspicuous veins of a lighter or darker colour than the rest of the leaves. Some have leaves that are mottled with speckles of silvery white (Hoya carnosa R. Br., Hoya pubicalyx). Some hoyas have leaves that are thin and translucent (Hoya coriacea Blume); some are so thick and succulent that they look more like crassulas than hoyas (Hoya australis ssp. rupicola, oramicola and saniae from Australia and Hoya pachyclada from Thailand).

Flowers

Hoya flowers are just as varied as the leaves, despite the fact that all are shaped like five pointed stars. They grow in umbels, usually with many flowers per umbel. Individual flowers range in size from as small as four to five millimetres in diameter (Hoya bilobata Schltr.) to well over three inches in diameter (Hoya imperialis Lindl. and H. macgillivrayi F. M. Bailey). The number of flowers per umbel varies from one (H. pauciflora Wight.) to 55 or even more. Hoya coriacea Blume has been known to have as many as 70, each measuring nearly 2 centimetres in diameter. The single flowered Hoya pauciflora Wight makes up for its paucity by its flower size of nearly an inch and a half in diameter.

Hoya flowers vary in textures as well as size, some being glabrous and shiny and some being quite hairy. They also vary in color. They come in the purest white, varying shades of pink from almost white to rubber-doll or bubble-gum pink, yellowish-pink, yellow, green, purple, brownish-red and brown. There are some that are so dark that they are often referred to as black. Until recently it was thought that a true red hoya was not ever likely to appear but recent discoveries make that seem possible. One of the two clones of Hoya mindorensis Schltr., from the Philippines, which are currently in circulation, comes very close to being a true red. Blue still does not appear to be represented in the Hoya genus.

Selected species

* Hoya acicularis
* Hoya acuminata
* Hoya acuta
* Hoya aeschynanthoides
* Hoya affinis
* Hoya africana
* Hoya alagensis (Philippines)
* Hoya alata
* Hoya alba
* Hoya albens
* Hoya albiflora
* Hoya aldrichii (Christmas Island)
* Hoya alexicaca
* Hoya amboinensis
* Hoya ambon
* Hoya amoena
* Hoya andalensis
* Hoya angustifolia (Philippines)
* Hoya angustisepala
* Hoya anncajanoae (Philippines)
* Hoya anulata
* Hoya apiculata
* Hoya apoda
* Hoya archboldiana
* Hoya ariadna
* Hoya arnottiana
* Hoya attenuata
* Hoya augustifolia
* Hoya aurantiaca (Philippines)
* Hoya australis - Australian Waxflower (Australia, Papua New Guinea)
* Hoya australis ssp. australis
* Hoya australis ssp. keysii
* Hoya australis ssp. naumanii
* Hoya australis ssp. oramicola
* Hoya australis ssp. rupicola
* Hoya australis ssp. sana
* Hoya australis ssp. tenuipes
* Hoya bandensis
* Hoya bella - Beautiful Hoya
* Hoya benguetensis (Philippines)
* Hoya benitotanii (Philippines)
* Hoya benvergarai (Philippines)
* Hoya betchei
* Hoya bhutanica
* Hoya bicknellii (Philippines)
* Hoya bilobata (Philippines)
* Hoya blashernaezii (Philippines)
* Hoya bordenii (Philippines)
* Hoya brevialata
* Hoya buotii (Philippines)
* Hoya burtoniae (Philippines)
* Hoya cagayanensis (Philippines)
* Hoya callistophylla
* Hoya calycina
* Hoya calycina ssp. calycina
* Hoya campanulata
* Hoya camphorifolia (Philippines)
* Hoya cardiophylla - Heart Leaf Hoya (Philippines)
* Hoya carnosa - Porcelain Flower, Waxplant (China, Souheast Asia, Malesia)
* Hoya caudata
* Hoya cembra - syn. Hoya odorata
* Hoya chlorantha
* Hoya chuniana
* Hoya chunii
* Hoya ciliata - syn. Eriostemma ciliata (Philippines)
* Hoya cinnamomifolia
* Hoya citrina
* Hoya clandestina
* Hoya clemensii
* Hoya clemensiorum
* Hoya collina
* Hoya cominsii
* Hoya compacta
* Hoya conchoi
* Hoya coriacea - syn. Hoya angustisepala (Philippines)
* Hoya coronaria
* Hoya crassicaulis (Philippines)
* Hoya crassipes
* Hoya cumingiana (Philippines)
* Hoya curtisii (Philippines and Thailand)
* Hoya cystiantha
* Hoya dasyantha
* Hoya darwinii - Ant Hoya (Philippines)
* Hoya davidcummingii (Philippines)
* Hoya dennisii
* Hoya densifolia (Philippines)
* Hoya deykei
* Hoya dickasoniana
* Hoya dimorpha
* Hoya diptera
* Hoya dischorensis
* Hoya diversifolia (Thailand, Malaysia, Indonesia, Philippines)
* Hoya dolicosparte
* Hoya edenii
* Hoya eitapensis
* Hoya elliptica (Thailand, Malaysia, Philippines)
* Hoya endauensis
* Hoya engleriana
* Hoya erythrina
* Hoya erythrostemma (Thailand)
* Hoya eitapensis
* Hoya excavata
* Hoya filiformis
* Hoya finlaysonii
* Hoya fischeriana (Philippines)
* Hoya fitchii (Philippines)
* Hoya flagelleta
* Hoya flavescens
* Hoya flavida
* Hoya fraterna
* Hoya fungi
* Hoya fusca
* Hoya fuscomarginata
* Hoya gigantangensis - syn. Hoya benitotanii (Philippines)
* Hoya gigas
* Hoya gildingii
* Hoya glabra
* Hoya globulosa
* Hoya golamcoiana (Philippines)
* Hoya gonoloboides
* Hoya gracilis - invalid name, syn. Hoya memoria (Philippines)
* Hoya graveolens
* Hoya greenii (Philippines)
* Hoya grifithii
* Hoya guppyi
* Hoya halconensis (Philippines)
* Hoya halophila
* Hoya hasselti
* Hoya heuschkeliana (Philippines)
* Hoya heuschkeliana ssp. cajanoae (Philippines)
* Hoya heuschkeliana ssp. heuschkeliana (Philippines)
* Hoya hellwigiana
* Hoya hypolasia (Papua New Guinea)
* Hoya imbricata - syn. Hoya pseudomaxima (Indonesia, Philippines)
* Hoya imperialis (Philippines, Malaysia)
* Hoya imperialis ssp. rauchii (Malaysia)
* Hoya inconspicua
* Hoya incrassata (Philippines)
* Hoya incurvula
* Hoya ischnopus
* Hoya javanica - syn. Hoya multiflora (Malesia)
* Hoya juanngoiana (Philippines)
* Hoya kanyakumariana
* Hoya kastbergii
* Hoya kenejiana
* Hoya kentiana (Philippines)
* Hoya kerrii - Heart Hoya (Philippines, Thailand)
* Hoya kloppenburgii (Malaysia)
* Hoya krohniana (Philippines)
* Hoya kuhlii
* Hoya lacunosa
* Hoya lacunosa ssp. lacunosa
* Hoya lacunosa ssp. pallidiflora
* Hoya lambii
* Hoya lamingtoniae
* Hoya landgrantensis (Philippines)
* Hoya lasiantha
* Hoya latifolia
* Hoya lauterbachii
* Hoya lazaroi (Philippines)
* Hoya leytensis (Philippines)
* Hoya limoniaca
* Hoya linavergariae (Philippines)
* Hoya linearis
* Hoya litoralis
* Hoya lobbii
* Hoya loheri (Philippines)
* Hoya longifolia
* Hoya lucardenasiana (Philippines)
* Hoya lucyae (Philippines)
* Hoya macgillivrayi
* Hoya macgregorii (Philippines)
* Hoya macrophylla
* Hoya madulidii - syn. Eriostemma madulidii (Philippines)
* Hoya magnifica
* Hoya megalaster
* Hoya meliflua (Philippines)
* Hoya meliflua ssp. fraterna (Philippines)
* Hoya meliflua ssp. meliflua (Philippines)
* Hoya membranifolia
* Hoya memoria (Philippines)
* Hoya meredithii
* Hoya merrillii (Philippines)
* Hoya micrantha
* Hoya microphylla
* Hoya microstemma
* Hoya minahassae
* Hoya mindorensis (Philippines)
* Hoya minibelle
* Hoya mitrata (Malaysia)
* Hoya monetteae (Philippines)
* Hoya montana
* Hoya motoskei - Spotted Waxplant
* Hoya multiflora - Shooting Star Hoya (Malesia)
* Hoya myrmecopa (Indonesia, Philippines)
* Hoya naumanii
* Hoya nabawanensis
* Hoya neo-caledonica
* Hoya neo-ebudica
* Hoya nicholsoniae
* Hoya nummularioides
* Hoya nyhuusiae
* Hoya oblongata
* Hoya obovata
* Hoya obscura (Philippines)
* Hoya obtusifolia
* Hoya obtusifolioides
* Hoya odetteae (Philippines)
* Hoya odorata (Philippines)
* Hoya onychoides
* Hoya oreogena
* Hoya ovalifolia
* Hoya pachyclada
* Hoya padangensis
* Hoya palawanica' (Philippines)
* Hoya pallilimba
* Hoya panayensis (Philippines)
* Hoya panchoi (Philippines)
* Hoya pandurata
* Hoya parasitica
* Hoya parviflora
* Hoya patella
* Hoya pauciflora
* Hoya paxtoni
* Hoya paziae (Philippines)
* Hoya pentaphlebia (Philippines)
* Hoya picta
* Hoya pimenteliana (Philippines)
* Hoya platycaulis (Philippines)
* Hoya plicata
* Hoya polystachya
* Hoya polyneura - Fishtail Hoya
* Hoya pottsii
* Hoya praetorii
* Hoya pseudo-littoralis
* Hoya pubera
* Hoya pubicalyx (Philippines)
* Hoya pulchella
* Hoya purpurea
* Hoya purpureo-fusca
* Hoya pusilla
* Hoya querinoensis
* Hoya quinquenervia (Philippines)
* Hoya quisumbingii (Philippines)
* Hoya ramosi
* Hoya retusa
* Hoya revoluta
* Hoya ridleyi
* Hoya rigida
* Hoya rotundifolia
* Hoya ruscifolia - syn. Dischidia ruscifolia
* Hoya salweenica
* Hoya samoensis
* Hoya schneei
* Hoya scortechinii
* Hoya serpens
* Hoya shephardell
* Hoya shepherdii - String Bean Hoya
* Hoya shortechinii
* Hoya siamica
* Hoya siariae (Philippines)
* Hoya sigillatis
* Hoya sipitangensis
* Hoya solaniflora
* Hoya soligamiana (Philippines)
* Hoya spartioides
* Hoya stoneiana
* Hoya subcalva
* Hoya subglabra
* Hoya subquintuplinervis
* Hoya surigaoensis (Philippines)
* Hoya sussuela
* Hoya telosmoides
* Hoya teretifolia
* Hoya thailandica
* Hoya thomsonii
* Hoya tomataensis
* Hoya tsangii (Philippines)
* Hoya uncinata
* Hoya vaccinioides
* Hoya vanuatuensis
* Hoya verticillata (Philippines)
* Hoya viracensis
* Hoya vitchii
* Hoya vitellina
* Hoya vitellinoides
* Hoya vitiensis
* Hoya wallichii
* Hoya walliniana
* Hoya wayetii (Philippines)
* Hoya waymaniae
* Hoya weebella
* Hoya whistleri
* Hoya wibergiae (Philippines)
* Hoya wightii

References

* Prodromus novae Hollandiae, Robert Brown, 1810.