Hoya carnosa (L.f.) R.Br.

Where It Grows

Kew currently lists eight native reporting regions: China South-Central, China Southeast, Hainan, Japan, Laos, Myanmar, Nansei-shoto and Taiwan. It lists East Himalaya as doubtful, separately from the native range. Its six introduced regions are Bangladesh, Fiji, Korea, Solomon Islands, Sumatra and Trinidad–Tobago. These broad regions describe reported distribution and do not mean the species grows throughout each area.

Reported distribution

Native, introduced and doubtful records are shown separately, following Plants of the World Online.

Green: native. Amber: introduced. Blue hatching: doubtfully present. Grey provides geographic context.

Introduced records in the Pacific

All reported regions and map notes

Native (8): China South-Central; China Southeast; Hainan; Japan; Laos; Myanmar; Nansei-shoto; Taiwan.

Introduced (6): Bangladesh; Fiji; Korea; Solomon Islands; Sumatra; Trinidad–Tobago. The first five are mapped; Trinidad–Tobago is text-only.

Doubtfully present (1): East Himalaya.

Sumatra and Solomon Islands are display spellings for Kew’s Sumatera and Solomon Is. Introduced records do not establish native origin. A garden, supplier location or nursery label is not a wild collection record.

Distribution adapted from Kew Backbone Distributions (CC BY 3.0). Simplified TDWG WGSRPD reporting-unit outlines reuse the existing Library map geometry. The Asia and Pacific panels use different scales. Grey regions do not establish absence.

Natural Habitat

The 1995 Flora of China account describes Hoya carnosa as a climbing epiphytic shrub and places its regional species treatment in mountain forests, usually on trees, at 200–1,200 m. This is a regional flora account under its historical circumscription, rather than a complete habitat or elevation profile across the species’ present-day range.

Publication and naming history

The original description of Asclepias carnosa in Supplementum plantarum (p. 170) emphasises smooth, fleshy, ovate leaves and gives China as its origin. It also states that the author had seen only two leaves and a flowering umbel. That limited material matters when comparing the short description with later accounts. The scanned title page bears 1781; Kew cites the name as published in 1782.

In his 1810 Prodromus (p. 460), Robert Brown described carnosa with fleshy, oval-oblong leaves, hairy corollas and corona segments grooved underneath. He also cautioned that several species might have been confused under the name. The page cites his separate Wernerian paper; the two works should remain distinct in the naming history.

In the journal version of his Asclepiadeae paper (1811, pp. 26–27), Brown explains that he named Hoya for Thomas Hoy, whom he praised as a cultivator. He again suggests that carnosa may include several species and calls for comparison of living plants. This historical concern does not by itself resolve the identities of plants now sold under the name.

James Traill’s early Chiswick account (pp. 19–22) describes leaves mottled with whitish-green spots and fragrant flowers. He also reports ripe seed and a seed-raised plant with paler flowers and smaller, thinner leaves. These observations document variation in cultivated material; they do not identify today’s named selections.

Historical names explained

Asclepias carnosa L.f. is the original name on which the combination Hoya carnosa (L.f.) R.Br. is based. A change of genus does not, by itself, describe a different species. The original description and Brown’s Hoya account provide the historical evidence; the separate preprint date is explained in the Brown reference under Sources.

Traill’s account shows why historical synonym lists need care. Traill reports a re-examination by Brown of material received from Loureiro, consisting of a leafy branch and separate flowers. He questions whether these belonged to the same plant and rejects the earlier identification with carnosa. This is a historical disagreement about that material, rather than a new ruling on accepted synonymy.

The plant, leaves and flowers

The 1995 Flora of China treatment describes carnosa leaf blades measuring 3.5–13 × 3–5 cm. These dimensions belong to that regional treatment; they are not limits verified for every cultivated selection.

The same treatment describes rounded clusters of about 30 flowers. The corollas are white, sometimes pink-centred, and measure 1.5–2 cm across. That measurement is for an individual corolla, rather than the diameter of the whole flower cluster.

What Research Has Found

In Mochizuki, Furukawa and Kawakita’s 2017 field study, settling moths carried carnosa pollinaria on the adhesive pads of their legs. Observations on Amami-Oshima, Japan, during 2013–2015, combined visitor records with examination of moth legs and flower structures. The authors’ explanation concerns those studied populations; it does not demonstrate the pollinator of every carnosa population or every Hoya species.

The same paper contains a moth-name discrepancy between its results narrative and tables. We retain that as an unresolved source question. The presence of pollinaria on an insect and successful pollen deposition also have different denominators; neither should be presented as a seed-set percentage.

Kuang and colleagues (2025) produced a near-complete reference genome from material recorded as accession 20170662 at South China Botanical Garden, reportedly collected in Yangshan, Guangdong, in 2017. This gives researchers a genomic resource. It does not identify commercial cultivars or resolve their parentage. The paper does not supply a herbarium voucher or determination history for the accession.