Origin and Habitat: Hoya lacunosaSN|26371]]SN|26371]] comes from India, China, Malaysia, Singapore, Thailand, Indonesia (Borneo, Java, Sumatra)
Habitat and ecology: It is a creeping epiphyte growing in open places and along forest edges often in masses closely covering the trunk and limbs of the host trees. In nature, H. lacunosa climbs along tree trunks, where ants build tunnels and nests among its roots and stems.

• Hoya lacunosa Blume
• Otostemma lacunosum Blume

• Hoya lacunosa Blume
• Otostemma lacunosum Blume
• Hoya lacunosa var. pallidiflora Hook.
• Hoya suaveolens Miq.

Description: Hoya lacunosaSN|26371]]SN|26371]] is an epiphytic diminutive trailer or climbing shrub with small, dense, cascading shining leaves and clusters, cream-white flowers. Flowers are white with yellow crowns. They are fuzzy little stars tightly curled appearing to be little balls. The blooms have a very clean, pleasant scent, especially fragrant at night, and appear in abundance from the spurs typical of hoyas. It is attractive both in leaf and flower. There are many cultivars and hybrids of this plant now.
In habit and mode of growth this species reminds one of the Hoya bellaSN|23711]]SN|23711]].
History: Hoya lacunosaSN|26371]]SN|26371]] appears to have first received conservatory culture at Kew over a century ago when it served as the basis of an illustration (t. 4826) in Curtis's Botanical Magazine under the common name “Furrowed Hoya”.
Stems: Thin, terete, very slender, to 1.5 m long, glabrous or sparsely pubescent, green, rooting from various points especially at the nodes.
Leaves: Leaves opposite, ovate or lanceolate, small (2-)3-5(-7) cm long, (1.2)2.5-3 cm wide, glabrous or subglabrous, veinless, coriaceous and fleshy, shining, apex acute, base rounded or wedge-shaped, marked above with a depressed line or midrib, lateral veins 2-4 pairs, obscure and with sections between the veins lacunose (slightly sunken) and convex beneath, whence the name we presume of lacunosa. Petiole short (ca. 3-12 mm long), thick, nearly glabrous.
Inflorescences (umbels): Developing along the stems. Peduncles in leaf-axils generally robust shorter than the leaf solitary bearing a flattened umbel of numerous flowers. Pedicels 5-13 mm long and thickened upwards.
Flowers: Pale yellow or white with a rich, cinnamon fragrance especially early in the morning or after dark. Sepals obtuse. Calyx of five ovate or elliptical rounded lobes denticulate on the margins and keel. Corolla radially symmetrical, 6-7 mm in diameter, white to greenish yellow, eventually reflexed, the inner surface clothed with a circle of velvety hairs. Tube conspicuously white villous inside; lobes suborbicular, much longer than tube. Corona lobes ovate, constricted at middle, outer angle rounded, inner angle acute, surface with a thin keel. Staminal crown of five spreading lanceolate lobes concave at the top, without furrows beneath exceeding stigma head. Pollinia subobovate.
Fruits: Follicles lanceolate, 5-7 cm long.

Bibliography: Major references and further lectures
1) Sir William Jackson Hooker, David Prain, Otto Stapf “Curtis's Botanical Magazine”, Volume 81 Reeve Brothers, 1855
2) George Don “A General System of Gardening and Botany” Rivington, 1838
3) Focke Albers, Ulrich Meve “Illustrated Handbook of Succulent Plants: Asclepiadaceae: Asclepiadaceae”, Volume 4 Springer Science & Business Media, 2002
4) Umberto Quattrocchi “CRC World Dictionary of Medicinal and Poisonous Plants: Common Names, Scientific Names, Eponyms, Synonyms, and Etymology” (5 Volume Set) CRC Press, 03 May 2012
5) “Plants & Gardens” Volumes 43-44 Brooklyn Botanic Garden, 1987
6) Dale Kloppenburg und Ann Wayman “The World of Hoyas - a pictorial guide”. A revised version. Orca Publishing Company, Central Point, Oregon, 2007
7) Anders Wennström und Katarina Stenman “The Genus Hoya - Species and Cultivation.” Botanova, Umeå 2008
8) Flora of China “9. Hoya lacunosa Blume, Bijdr. 1063. 1826.” FOC Vol. 16 Page 232 <http://www.efloras.org> Web.

Cultivation and Propagation: Hoya lacunosa is white-yellow bloomer that flowers prolifically once established. It is considered as an easy-to-care and very temperature-tolerant plan and is suitable for hoya beginners. It is topical plant that once again will do much better with some extra warmth and humidity. In cultivation this species adapts to growing in a basket. When in bloom it is a very interesting plant, if only for the wonderful perfumed scent of the flowers alone. They can transform any room into a sweet smelling paradise..
Growth rate: This is a compact shrubby species that grows really well and strong in optimal condition.
Potting medium: Because it is an epiphyte benefits from being potted up in a very well-draining and porous potting medium that allows some air to get to the roots; typical mixes include, peat, with some fibrous soil and sand along with large-grade drainage material such as perlite, pumice, or ceramic balls. Often specialized hoya growers either use only chopped coconut husk or a good orchid potting mixture for growing their hoya plants. The medium needs to be moisture-retentive.
Fertilization: The plants should be fed regularly with a fertilizer suitable for epiphytic plants.
Watering: Medium and low tolerance to drought growth, so it should be kept moist, but can dry up a bit from time to time without being damaged by it. Water regularly in summer, but do not overwater ( wet-sensitively) and let the plants to dry out between watering and then water again. Its roots are easily lost in pots that stay damp for any length of time. Keep quite dry with ample airflow in winter (It would probably tolerate one watering a month). In the rest period no high atmospheric humidity. Care must be taken with watering as they tends to become swollen and untidy in growth habit if given too much water and shade. This plant will suffer considerably in the dry environment of northern centrally heated homes in the winter. If you want this plant to be happy in the winter grow it in a room with lots of humidity.
Fertilization: During the growing season enrich the soil using a fertilizer rich in potassium and phosphorous, but poor in nitrogen, because this chemical element doesn’t help the development of succulent plants, making them too soft and full of water.
Exposition: This hoya species prefers bright light but no direct sun. Outside half shade to shade (filtered sunlight or afternoon shade tolerated), inside it will need a reasonably light room in order to actually grow, although it will still get by even in a shadier spot and can be positioned almost anywhere in homes or offices. It subject to sunburn if exposed to direct sun for too long. Tends to bronze in strong light, which encourages flowering and heavy leaves production.
Temperature: The ideal for this species, temperature is between 20 and 25 but never below 10ºC. (Outdoor zone: At least Zone 10, possibly cooler).
Spring: When winter ends and they begin to grow again, they will require much water and soaking the pots will no longer put the plants at risk for rot. In the spring they will grow well in partial shade and leaving them out in the rain may provide them with the water they need.
Summer: In the summer months they will tolerate heavy rain, but will be just as happy if the season is dry. They will tolerate hot weather outdoors as long as they are kept in strongly filtered light and this will encourage them to flower. They also enjoy some fertiliser. Moving the plants as they are developing buds may cause them to spontaneously abort the flowers all together.
Autumn: In the fall keep them outdoors until the night time temperatures drop below the 10°C.
Winter: Winter care presents no problems at 12° C with plenty of light. In winter be sure to take extra precautions to keep them dry, because damp cool conditions when the plants are resting is an invitation to fungal infections, but - according to temperatures –some occasional lit watering may be useful.
Maintenance: Prune the plant lightly to keep it tidy.
Repotting: In any season it's best to lay the stems out for several days before replanting them and then pot them only in dry soil and withhold any water until they begin to shrivel or start growing again. Re-pot every 2 years.
Pest and diseases: Hoyas are generally fairly easy to grow, especially if kept pest-free. They are very susceptible to stem and root mealy bug, which can be fought easily with common pesticides, and damage from these may well initiate fungal attack. Any time when there is a dead or dying stem in the pot it is important to remove it immediately and completely before other healthy stems can become ill too, isolate the healthy parts, dry them off, and re-root them in new compost.
Medical uses: In China decoctions of all parts of H. lacunosa are used to detoxify, in insects bites, draw out pus, and reduce swellings.
Warning: As H. lacunosa belongs to the Asclepiadaceae family it contains a white, milky sap, which may cause skin irritations.
Propagation: This species propagates readily from stem cuttings, whether in water, in soil or in a sterile medium (such as perlite).