Leucospermum cordifolium (Salisb. Ex Knight) Rourke
Common names: Pincushion, Bobbejaanklou, Luisiesboom, Luisiesbos.
From the middle of July to the end of November groups of Leucospermum cordifolium shrubs provide vivid splashed of orange and red in the Fynbos section of Kirstenbosch. Many visitors from all over the world may recognise the flowers from flower arrangements they have seen in their own country. Nurseries in Israel, California, Hawaii, Zimbabwe, Australia and New Zealand produce large amount of cut flowers of hybrids and cultivars of this South African plant. In South Africa it is a popular garden plant as well as a much-used cut flower.
Leucospermum cordifolium is a rounded spreading shrub up to 2 m in diameter and about 1,5 m high, with a single main stem and horizontally spreading stems, hard green leaves and 1 to 3 large inflorescences borne at the end on the stem. The inflorescences consist of a large number of small flowers. It is the stiff protruding styles of the flowers which are the source of the common name "pincushion" for this genus.
Distribution and habitat
It grows in acid, nutrient poor soils in a fairly small area in the South Western Cape, from the Kogelberg to the Soetanysberg near Bredasdorp. It is part of the Cape Floral Kingdom and occurs only in the winter rainfall area with its wet winters from May to September and hot, dry summers from December to the end of February.
Derivation of name and historical aspects
Leucospermum cordifolium belongs to the protea family and is indigenous to South Africa. Other genera of the protea family, which produce striking and ornamental flowers, are Leucadendron and Protea.
An added attraction during flowering time are the numerous birds found near the plants. In the early hours of the morning the abundant nectar flow attracts a variety of small insects, which in turn attract the Cape Sugar bird and three species of Sunbird. These insectivorous birds consume the small insects as well as the nectar, and in the process transfer pollen from one flower to the next. The flowers are not self-pollinating and depend on the small Scarab beetles and the birds for pollination. The birds are accustomed to the visitors in the Gardens and provide great photo opportunities when feeding on the flowers.
Only a few large, hard, nut-like seeds are produced by each inflorescence. In their natural environment the seeds are collected by ants, stored in the soil, and germinate only after a fire has killed the mature plants and returned the nutrients back to the soil.
Growing Leucospermum cordifolium
Seed is sown at the end of February when the nights get cooler. For best results always use fresh seed. Soak Leucospermum seed in water to which hydrogen peroxide has been added, at the ratio of 1% of the total volume. This loosens the outer seedcoat and oxygenates the seed. The softened seedcoat is rubbed off. Dust the seed with a systemic fungicide. Sow on a well-drained medium, firm down and cover with a layer of sand. Seed can be sown in an open seedbed in full sun, or in a seed-tray placed in a sunny position. Germination starts after three to four weeks. The seedlings will have to be pricked out in batches, as the seed germinates at different times. If the root is very long and has been removed without damaging the root-tip, the root-tip should be pinched off to promote root growth.
Cultivars or hybrids are propagated by cuttings, which can be made from November to March. The cuttings should be semi-hardwood, 6-10 cm long, of the current season's growth. The cuttings are dipped for about four seconds in a rooting hormone solution and placed in a growing house with bottom heat (25ºC) and intermittent mist. The young seedlings or cuttings grow fast and are ready to be planted out after a year. Three years after sowing the plants will produce their first flowers.
Leucospermum cordifolium is an excellent garden plant, as a focal point or planted in groups, and provides good, long-stemmed cut flowers. The plants are relatively short lived and become leggy after about eight years. They are very sensitive to the fungal disease Phytophthora cinnamomeum.
Hanneke JamiesonKirstenbosch National Botanical Garden
Plant Type: Shrub
SA Distribution: Western Cape
Soil type: Sandy, Loam
Flowering season: Spring, Winter
PH: Acid, Neutral
Flower colour: Red, Pink, Yellow, Orange
Aspect: Full Sun
Gardening skill: Average