This charming shrub with attractive flowers which appear to be made of porcelain, is one of the buchus which form part of the citrus family (Rutaceae). Rutaceae have volatile oil glands dotted on the leaves and fruit that release a distinctive scent when touched or crushed.

Description
This evergreen, short, bushy shrub grows to a height of 100-450 mm. With its compact growth habit, showy flowers and aromatic foliage, it is an ideal garden or pot plant.

Solitary, large white flowers, 10-30 mm across, are borne on a slender, reddish branch. The flower has five rounded white petals, the glistening white resembling porcelain, with a suffusion of red along the veins. The underside of the petal is flushed pink and the sepals are leaf-like, glabrous or hairy and rolled. The flowering buds are red before they open and flowers decorate the shrub from mid-winter to spring (July to October). Flowers are mildly fragrant.

New stems are lightly hairy. Each anther is tipped with a tiny, curiously sticky gland. Staminodes are, erect or slightly incurved, 2.5-4.4 mm long, and like the stamens are hairy. The stamens are peculiar, each carrying a conspicuous red terminal knob or gland.

Small, oblong, light green leaves are densely to rather sparsely arranged on branches. The leaves are smooth above with revolute margins (rolling back), are 0.5-1 mm long, sometimes with a recurved apex, and are aromatic, with 10-60 inconspicuous glandular dots (oil glands). The mature seed capsule is enclosed by a large, leaf-like, green calyx segment.

Distribution
Adenandra uniflora occurs on the sandstone slopes of the southwestern Cape mountains from the Cape Peninsula to the Kleinrivier Mountains.

Derivation of name
The genus name of Adenandra is derived from the Greek aden meaning, a gland; ander, a man and uniflora derived from the Latin, meaning one flower.
The genus Adenandra displays large showy flowers but is less scented than the other genera. There are 18 species found in this genus and it is endemic to the southwestern part of Western Cape.

Adenandra uniflora vs. Adenandra villosa
Adenandra uniflora can be distinguished from A. villosa by its relatively soft leaves with revolute margins, solitary flowers, large, leaf-like calyx segments and smaller anthers. A. villosa bears clusters of white flowers at the tips of branches with a maroon streak in the centre of each petal. Leaves are minute and flat, sepals flat. This buchu grows to a height of 1 m and occurs on sandy soils from Malmesbury to Caledon in Western Cape.

Ecology
This buchu is found growing in sand and among sandstone outcrops at low to moderate altitudes, often on burnt patches and sometimes in disturbed habitats.

Seed are borne in a 5-chambered capsule, one black and shiny seed per seed chamber, which separate from each other completely when mature. Each seed case splits down the inner side and through differential drying and contracting of the inner layer, forcibly ejects its single seed. This phenomenon is known as ballistic dispersal.

Uses and cultural aspects
Dried leaves are used for potpourri.

Growing Adenandra uniflora

Adenandra uniflora grows best when planted in full sun and needs adequate water during the hot summer months. It requires a soil that is well drained, composted and enriched with a well-balanced fertilizer (3:2:1). It is slow growing and needs space in the garden bed to allow it to develop to its full potential without being squashed by other faster growing plants.

Buchu naturally occurs in mixed fynbos and ideally should be used in this way in a garden. Plant the china flower with companion plants such as restios, pelargoniums, Helichrysum, Phylica, Euryops, Felicia and Leonotis. It can be grown as a border plant, planted in masses or planted in a pot where its immaculate flowers can be admired at close range.

Like other fynbos plants, planting buchus in your garden is best done after the first good winter rains, (May to July at the Cape). Buchus respond to fairly dense plantings, which help to retain soil moisture. An annual mulching of well-rotted compost is advised, to reduce weeds and keep the soil temperature low.

Buchus can be grown from seed or cuttings. Fresh buchu seed is sown in autumn. The seed are sown into a tray containing a well-drained medium of equal portions of sand, loam and compost. Use some of the medium to cover the seed and water. Place in a covered area with good light and air circulation. Keep medium damp. Germination occurs in 1 to 2 months.

Young seedlings are pricked out into 0.5 litre bags containing a fynbos medium, when four true leaves have developed. Pinch out the growing tips of the seedlings to encourage bushy growth. Flowers are produced after two years.

Cuttings have the advantage of producing a larger flowering plant quicker than seedlings. Tip cuttings, 50-70 mm, are taken from the current year's growth. Prepare cuttings by making a clean cut below the node and remove a third of the foliage. Dip the base of the cutting in a rooting hormone. Firmly place the cuttings in a medium of 50% bark and 50 % polystyrene. Ideally these cuttings should now be placed in a well-aerated propagation unit with a bottom heat of 24° C. Rooting occurs in 9 to 11 weeks. Carefully pot the rooted cuttings using a well-drained, humus-rich fynbos-potting medium (2 parts leaf mould, 1 part coarse sand). Plants will be ready for planting in 7 to 8 months. Feed regularly with a well-balanced nutrient. Yellow leaves can be treated with an application of iron chelate.

References

• GOLD, M. 1992. The buchus. Cultivation and propagation. National Botanical Institute, Kirstenbosch.
• JACKSON, W.P.U. 1977. Wild flowers of Table Mountain. Howard Timmins, Cape Town.
• MACOBOY, S. 1994. What flower is that?. Boks Books International, Durban.
• MASON, H. 1972. Western Cape Sandveld flowers. Struik, Cape Town.
• PALMER, E. 1985. The South African herbal. Tafelberg, Cape Town.
• STOKES, H. 1985. Flora of Table Mountain. Murray Coombes Publishers, Cape Town.
• VAN DER SPUY, U. 1971. South African shrubs and trees. Hugh Keartland Publishers, Johannesberg.

Norma Jodamus,
Horticulturist, Kirstenbosch NBG
July 2003