Hoya lacunosa, sold as Furrowed Wax Plant, sits in Asclepiadoideae (formerly Asclepiadaceae), a subfamily of Apocynaceae that contains the classic milkweeds and a large radiation of epiphytic succulents. A south-east Asian epiphyte with thick narrow-pointed green leaves marked with a sunken central vein (lacuna), giving the trade name. Produces dense round clusters of small fragrant white flowers in late spring. Most species grow as forest epiphytes draping from tree branches, which is why they suit hanging-pot cultivation indoors.
Care facts at a glance
- Light
- Bright indirect
- Water
- Water when the top 2 to 3 cm of mix has dried.
- Humidity
- 50–80 %
- Temperature
- 18–27 °C
- Soil
- Free-draining epiphyte mix of orchid bark, coco coir, and perlite for excellent aeration.
- Origin
- Tropical and subtropical Asia and Africa, mostly epiphytic in forest canopies.
- Mature size
- Trailing stems to 1 m or more in mature plants.
Overview
Hoya lacunosa belongs to a tropical-Asian and African epiphyte clade closely related to the more familiar Hoyas. A south-east Asian epiphyte with thick narrow-pointed green leaves marked with a sunken central vein (lacuna), giving the trade name. Produces dense round clusters of small fragrant white flowers in late spring. Many species form intricate flower structures with five-pointed coronas, a hallmark of the milkweed family that puts them among the most distinctive cultivated tropicals.
Care Priorities
- Bright filtered light, never direct midday sun.
- Free-draining epiphytic mix with orchid bark.
- Water when the top of the mix has dried.
- Steady humidity above 50 percent supports tight new growth and flowering.
Common Problems
Yellowing leaves are usually overwatering. Brown crispy edges signal dry air. Failure to flower is most often insufficient light or too-frequent repotting — the plants set buds best when slightly root-bound.
Sources & further reading (2)
- encyclopedia — accessed 2026-04-29
- botanical-garden — accessed 2026-04-29
Frequently asked questions
Why is there a deep groove down each leaf?
H. lacunosa leaves carry a characteristic sunken midrib that gives the species its name (*lacunosa* meaning 'furrowed'). The groove is species-typical and consistent across plants regardless of growing conditions.
Are these related to Hoya?
Yes — Dischidia, Ceropegia, and Hoya all sit in subfamily Asclepiadoideae of Apocynaceae. They share the milkweed-style flower structure with a five-pointed corona, the white milky sap, and the epiphytic growth habit, though leaf shapes differ widely between genera.
Can I root cuttings in water?
Yes — most species in this group root readily in water once the cut end has callused for a day or two. Pot up into free-draining epiphytic mix once roots reach 2 cm long.
