Hoya buntokensis – a rare Bornean climber with delicate, sweet-scented blooms
 
Hoya buntokensis is one of the more recent discoveries in the Hoya genus, officially described in 2021 by Siti Rahayu and Michele Rodda in Blumea 66(3): 237. Native to Central Kalimantan, Indonesia, this rare species combines the charm of finely textured foliage with compact umbels of pale pink flowers. It’s a collector’s Hoya that speaks more through subtlety than extravagance — elegant, botanical, and rooted in the rainforests of Borneo.
 
Growth & Form of Hoya buntokensis
Hoya buntokensis grows as a slender, twining epiphyte with a calm, steady pace. Its leathery leaves are elliptic to narrowly ovate, usually 6–10 cm long and 2–3 cm wide, with faint yet structured venation and a light gloss on the upper surface. Once mature, vines can easily reach 1.5–2 metres if given support.
 
When conditions are right, it produces neat, dome-shaped umbels with 15–25 small flowers, each around 5–6 mm in diameter. The corolla is creamy white to soft pink, with a yellowish-pink corona that deepens slightly toward the centre. The flowers curve backward (revolute), typical for Hoyas in section Acanthostemma, and release a gentle sweet fragrance noticeable during the evening hours.
 
Natural Habitat of Hoya buntokensis
In the wild, Hoya buntokensis grows epiphytically on trees or occasionally as a lithophyte on mossy rocks in the lowland rainforests of Central Kalimantan. The type locality near Buntok lies at an elevation of about 100–300 metres. The environment there is consistently warm, humid, and shaded — a microclimate that this species still prefers in cultivation.
 
These natural cues explain why it appreciates stable humidity and good air movement rather than extreme light or dryness. Its resilience in such filtered, consistent conditions makes it suitable for terrariums, grow cabinets, and bright indoor environments with warm temperatures.
 
Care for Hoya buntokensis
Light – Prefers bright, indirect light. Avoid harsh midday sun, which can damage the leaves.
Watering – Water when the upper layer of substrate feels dry; avoid standing water. The roots are fine and sensitive to excess moisture.
Humidity – Performs best at 60–80%. Gentle air circulation prevents fungal issues.
Temperature – Ideal range 20–28 °C; avoid temperatures below 15 °C.
Substrate – Use a coarse, airy mix such as bark, perlite, and sphagnum, or a mineral semi-hydro substrate for steady moisture without stagnation.
Feeding – Apply diluted fertilizer every few weeks during active growth. Less is safer than more.
Propagation – Easy to root from one- or two-node cuttings placed in warm, humid conditions.
Growth rate – Moderate. Once established, vines lengthen steadily throughout the year.
Toxicity – Non-toxic to humans and pets.
 
Common Issues with Hoya buntokensis
Because it naturally prefers stable humidity, leaves may wrinkle or spot if watering becomes inconsistent. Root rot can occur in dense or compact soil. Flowering may delay if the plant is frequently moved or pruned too heavily. Provide consistent warmth, bright light, and minimal disturbance to encourage blooms.
 
Etymology & Taxonomical Context
Hoya buntokensis was described by S. Rahayu and M. Rodda in 2021 (Blumea 66(3): 237). The species name “buntokensis” refers to the town of Buntok in Central Kalimantan, the region where the type specimen was collected. It belongs to Hoya section Acanthostemma, a group characterized by small, recurved corollas and compact umbels. The formal taxonomic citation is:
Hoya buntokensis S.Rahayu & Rodda, Blumea 66(3): 237 (2021) 
 
Additional Notes for Collectors
Hoya buntokensis remains scarce in cultivation, especially outside Southeast Asia. Its delicate floral architecture, subtle fragrance, and authentic wild origin make it a rewarding species for advanced Hoya growers and collectors of true botanical taxa. It thrives in warm, stable indoor conditions and transitions well to semi-hydro setups once established.
 
 
FAQs about Hoya buntokensis
Is Hoya buntokensis a fast grower?
No. It grows at a moderate pace and focuses first on root development. Growth speeds up once the root system is established.
Does Hoya buntokensis need high humidity?
Yes — consistent humidity between 60–80% helps it stay turgid and promotes flowering.
Can Hoya buntokensis grow in semi-hydro?
Absolutely. It adapts well to mineral substrates if roots are transitioned carefully from organic media.
What makes Hoya buntokensis different from similar species?
It has narrow, structured leaves, compact umbels with revolute corollas, and a distinctly sweet scent — a combination rare even within Acanthostemma Hoyas.
Is Hoya buntokensis pet-safe?
Yes, it is non-toxic to cats, dogs, and humans.
 
 
Bring a genuine piece of Borneo’s flora into your collection with Hoya buntokensis — a rare, scientifically described species admired for its refined leaves and soft, fragrant blooms. Ideal for collectors seeking an authentic wild-origin Hoya that grows beautifully indoors under stable, bright conditions.