Hoya carnosa, the porcelain flower or wax plant, is a species of flowering plant in the family Apocynaceae, native to East Asia. It is a common house plant grown for its attractive waxy foliage, and sweetly scented flowers. It is grown well in pots and hanging baskets.
Hoya carnosa has been in cultivation for more than 200 years and has given rise to many cultivars that vary in foliage form or flower color. In cultivation in the UK it has gained the Royal Horticultural Society's Award of Garden Merit.
Description
Hoya carnosa makes faintly succulent shoots with smooth, pale gray, and bare surfaces that twine and climb. The perennial leaves are wide oval to longitudinal oval or heart-shaped. They are slightly succulent, fleshy with a waxy glossy surface, 3–5 centimetres (1.2–2.0 in) wide and 3.5–13 centimetres (1.4–5.1 in) long, with a petiole of about 1–1.5 centimetres (0.39–0.59 in). The spindle-shaped fruits measure 6 to 10 × 0.5 to 1.5 cm.
Flower
The inflorescence is made up of numerous flowers, hanging or more upright, which are grouped in an umbel. The flowers are typically light pink, but may vary from near-white to dark pink; they are star-shaped, and are borne in clusters. The thick flower corollas look as if made from porcelaine or from wax, leading to the plant's common names. The surface of the flowers is covered in tiny hairs giving them a fuzzy sheen. They are heavily scented and may produce excess nectar that drips from the flowers. A single flower (corolla) has a diameter of 1.5 to 2 cm.
Like most species of Hoya, H. carnosa flowers grow from specialised perennial peduncles; sometimes these structures are referred to as spurs. These appear from the axils of the leaves and stem; flowers may not be produced when the spurs first appear, but in time buds emerge from their tips. New flowers are produced on these same spurs every year, so they should not be removed.