Hoya linearis
A Himalayan hoya with hanging, hairy stems and narrow, cylindrical leaves up to about 5 cm long. White flowers with a pale pink corona open in stalkless clusters at the stem tips.
Common names: slender wax flower [4]
Traits at a glance
| Leaf shape | Linear (narrow, strap-like) |
|---|---|
| Leaf length | 2.5–5 cm [1] |
| Leaf width | 5 mm [1] |
| Texture | Thick and succulent; Hairy |
| Veins | Veins not visible |
| Leaf markings | Plain green |
| Leaf notes | Flora of China gives a linear blade 2.5–5 cm long and about 5 mm wide with obscure lateral veins [1]. Hooker described living leaves as cylindric, deeply grooved beneath and 1½–2 inches (about 3.8–5 cm) long [3, 2], and RHS calls them fleshy [4]. Hairiness varies: the midrib may be glabrous or hirsute [2]. |
| Growth habit | Trailing or pendent |
| Flower colour | White, Pink |
| Flower diameter | 0.8–1.2 cm [1] |
| Flowers per umbel | 10–13 [4] |
| Fragrance | Fragrant [4] |
| Flower notes | Umbels are terminal, stalkless (sessile) and many-flowered, on pedicels about 2.5 cm long [1]. The corolla is white; Hooker described the corona of the Sikkim plant as very pale pink [3]. |
Identification
Hoya linearis is easy to recognize among cultivated hoyas because its leaves are narrow cylinders rather than flat blades. Flora of China describes the blade as linear, 2.5–5 cm long and about 5 mm wide, with the lateral veins hidden [1]. Hooker, working from a living plant, described the leaves as cylindric, slightly pointed, dark green and deeply grooved on the underside, 1½–2 inches (about 3.8–5 cm) long [3]. In a recent key to the hoyas of Nepal, the character that picks it out is linear leaves less than 5 mm wide [7].
The stems hang rather than climb. Flora of China gives them up to 1.5 m long and hairy [1], and Hooker described the whole plant as more or less covered in soft, spreading hairs, with slender, flexuous, tufted stems a foot or more long [3]. The hairs are not uniform: the midrib may be hairless or hirsute [2].
Flowers come in stalkless clusters at the ends of the branches. The corolla is white and 0.8–1.2 cm across [1]; Hooker gave half an inch for the plant he described and called its corona lobes very pale pink [3].
How to tell it from similar plants. The other narrow-leaved hoya from the region with a page here, Hoya retusa, has flat leaves that widen toward a broad, notched tip, and it is hairless with only one to three flowers together. H. linearis has cylindric, pointed leaves and hairy stem tips and umbels [2].
Naming and trade labels
The accepted name is Hoya linearis Wall. ex D.Don, published in 1825 [8]. The history is slightly tangled. Hooker noted that Wight’s original description was drawn from Wallich’s specimens that combined leaves of one plant with a detached flower of another, which may belong to a different species [2]. He then split the plants into var. nepalensis (corolla papillose and finely hairy inside) and var. sikkimensis (corolla hairless inside, corona lobes longer and narrower), treating them as one species because habit and inflorescence were identical [2, 3]. WCVP now lists both varieties as synonyms of the species [8], so a label with either varietal name refers to H. linearis.
The RHS uses the common name slender wax flower [4], and its hoya growing guide lists the species with the Award of Garden Merit as a trailing plant for hanging planters [5].
Growing it
The RHS publishes a profile for this species, so the notes below are species guidance where cited to that profile, with general hoya advice added where the profile is silent. RHS recommends a fast-draining, peat-free, loam-based compost with extra organic matter, bright but indirect light shaded from hot sun, moderate watering while in growth with a balanced liquid feed each month, and compost kept only just moist in winter [4]. It rates the plant H1b, meaning a minimum temperature range of 10–15 °C, and notes that hoyas resent repotting and can stay in one pot for years [4]. See the light guide, watering guide and substrate guide for the reasoning behind these steps.
The wild habitat points the same way. Flora of China places the species in evergreen forest at 1,500–2,000 m [1], and Hooker recorded it in Sikkim at 3,000–6,000 ft [2], which is cooler than lowland tropical forest. No institution publishes a humidity figure for it; the RHS genus guide suggests a tray of damp gravel under the pot during the growing season [5]. Because the stems hang, the RHS suggests a hanging basket [4]; see trellising vs trailing. The profile lists mealybugs as a possible pest [4]; see hoya pests.
Flowering
Flowers are borne in terminal, sessile, many-flowered umbels [1]. RHS gives 10–13 fragrant, white, star-shaped flowers per cluster in late summer [4]. Flora of China records flowering in September [1], the plant Hooker described flowered in cultivation in October [3], and a Darjeeling survey recorded fertile plants from August to November [6].
General RHS hoya advice applies here too: leave old flower stalks in place because new flowers often form on them, and do not move a plant once buds have formed [5]. If a plant never flowers, work through the not-blooming guide.
Care profile
Based on guidance published for this taxon by the institutions cited. About care basis
| In the wild | Plant with hanging stems in evergreen forest at 1,500–2,000 m in northwest Yunnan [1]; Hooker recorded it in Sikkim at 3,000–6,000 ft, roughly 900–1,800 m [2]. A 2022 survey found it growing as an epiphyte at 1,114 m in the Darjeeling hills [6]. |
|---|---|
| Light | RHS advises bright, indirect light with shade from hot sun [4]. The same profile's summary fields list full sun or partial shade, so the cultivation note is the more specific guide. |
| Watering | Water moderately while the plant is growing and keep the compost only just moist in winter [4]. |
| Humidity | No humidity figure is published for this species. General RHS hoya advice is to raise humidity in the growing season by standing the pot on a tray of damp gravel or clay pellets [5]. |
| Potting mix | A fast-draining, peat-free, loam-based compost with extra organic matter [4]. The RHS genus guide suggests equal parts orchid bark, peat-free multipurpose compost and coarse perlite for hoyas in general [5]. |
| Minimum temperature | 10 °C (50 °F), RHS hardiness rating H1b, a minimum range of 10–15 °C [4] |
| Difficulty | Moderate (editorial rating). RHS profiles it as a houseplant with fleshy leaves [4], which meets the rubric's easy test, but its wild habitat is evergreen forest at 1,500–2,000 m [1], which meets the demanding test; with the two signals in conflict it is rated moderate. |
Look-alikes
Hoya retusa
Both have very narrow leaves, but H. retusa leaves are flat, widen gradually to a broad notched tip, and the plant is hairless with flowers borne one to three together; H. linearis leaves are cylindric and pointed, and the stem ends and umbels are hairy [2].
Related guides
Synonyms
Names that WCVP treats as synonyms of Hoya linearis [8]. Plants are sometimes still sold under these names.
- Hoya linearis nepalensis Hook.f.
- Hoya linearis sikkimensis Hook.f.
Sources
- Hoya linearis — Flora of China Vol. 16. eFloras / Missouri Botanical Garden & Harvard University Herbaria. Leaf and flower measurements, habit, habitat and elevation in China. Accessed 30 September 2026.
- The Flora of British India, vol. 4 (1883), Hoya by J. D. Hooker, pp. 52–62 (H. linearis p. 53; H. retusa p. 56). L. Reeve & Co., London (scan via Internet Archive, NCSU Libraries copy). Terete hirsute leaves, terminal sessile umbels, Nepal and Sikkim localities and elevations, varieties, comparison with H. retusa. Accessed 30 September 2026.
- Hoya linearis, Curtis's Botanical Magazine vol. 109, t. 6682 (1 April 1883). L. Reeve & Co., London (scan via Internet Archive, Missouri Botanical Garden copy). Description of the Sikkim plant flowered in cultivation: leaf size and grooving, hairiness, corolla size, pale pink corona, treatment as var. sikkimensis. Accessed 30 September 2026.
- Hoya linearis (slender wax flower) — RHS Plant Profile. Royal Horticultural Society. Common name, fleshy leaves to 5 cm, 10–13 fragrant flowers per cluster, hardiness H1b, cultivation, light, watering and compost. Accessed 30 September 2026.
- How to grow hoya — RHS Growing Guide. Royal Horticultural Society. Genus-level guidance on humidity, compost, leaving flower stalks, not moving plants in bud; lists H. linearis with the Award of Garden Merit. Accessed 30 September 2026.
- Rai & Moktan (2022), An updated checklist of vascular epiphytes in the Darjeeling Himalaya, India. Check List 18(6): 1279–1319. Pensoft (open access). Recorded as a holoepiphyte at 1,114 m in Darjeeling; fertile August–November. Accessed 30 September 2026.
- Rokaya, Kasaju & Khadka (2020), Hoya polyneura (Apocynaceae), an addition to the flora of Nepal. J. Jpn. Bot. 95(6): 354–357. The Editorial Board of The Journal of Japanese Botany (J-STAGE). Key to Nepal hoyas: H. linearis separated by linear leaves less than 5 mm wide; key to its two varieties. Accessed 30 September 2026.
- Hoya linearis Wall. ex D.Don — World Checklist of Vascular Plants record (via GBIF). Royal Botanic Gardens, Kew; dataset published 2026-06-04, CC BY 4.0. Accepted name, authority, synonyms and native range. Accessed 30 September 2026.
- Hoya linearis — Plants of the World Online. Royal Botanic Gardens, Kew. Link built from the IPNI identifier 98540-1; POWO displays the same WCVP data. Accessed 30 September 2026.