Stangeria eriopus, not often seen in cultivation, develops into a most attractive perennial with large fern-like leaves, which is why it is often mistaken for a fern.
Stangeria eriopus is a slow-growing perennial which lives to a great age. The body of the plant consists of a large tuberous root which is swollen and carrot-shaped. The upper portion is the stem which branches and can form up to 10 heads. Each growing point of the stem produces one leaf at a time. When young, the leaf is rolled up at the tip (circinate) and fern-like, varying in length from 0.25-2 m depending on the habitat. A single cone is produced on each growing point. Cones seem to be produced throughout the year and are 100-250 x 30-40 mm. Male and female cones are borne on separate plants. The male cone is cylindrical and tapers at the apex. The female cone, 180 x 80 mm, is egg-shaped with a rounded tip.
Distribution and habitat
Stangeria eriopus occurs in coastal grassland and inland forests along the east coast of South Africa, from the Bathhurst District, ± 33° 30' S, to just south of the Mozambique border, 27° S. Plants usually never occur further than 50 km from the coast. They occur near the sea, but in sheltered habitats as they do not tolerate the salt spray.
Stangeria eriopus grows in full sun in short grassland, in light shade under trees and in dense shade in the coastal forests. Generally Stangeria grows in sandy soils as well as on granite soils. In the Transkei, plants have been seen to grow on heavy black clay which is slightly acid. Annual rainfall varies from 1 000 mm in the north to ± 750 mm in the southern part of the distribution area. About two thirds of the rainfall occurs in the summer months. The average minimum temperature in the southern part of the distribution range is 14° C, increasing to 17° C in the Durban area and probably higher on the Mozambique border. Frost occurs very seldom in this area.
Derivation of name and historical aspects
This species was first described by Kunze in 1836 from a sterile specimen collected by Drège. It was misidentified as a fern. Dr William Stanger sent a live plant to England and in 1851 it coned, which revealed its true identity. It was named by Moore in 1853 as Stangeria paradoxa ; however, in 1892, Baillard resurrected Kunze`s specific name eriopus. Stangeria eriopus is the only member of the family Stangeriaceae. The generic name honours Dr Stanger and the specific name eriopus refers to the velvety hair which covers the stem of the leaf when it first appears.
At Kirstenbosch, all cycads are hand pollinated to prevent hybridization and improve the production of viable seed. Stangeria eriopus is an exception as there is no danger of it hybridizing with the other cycads. It is left to pollinate naturally by wind and insects which produces good quantities of viable seed.
Uses and cultural aspects
Extensive use is made of Stangeria by the Xhosa and Zulu people for medicinal purposes, especially the root which is used as a purgative and in the treatment of headaches; it is applied to damaged teats of cattle. Xhosa women with babies wear a necklace of Stangeria root pieces.
Huge quantities of Stangeria eriopus are removed by users of traditional medicines. Crouch (2000) mentions research by Osborne which estimated that 3 410 lignotubers (totalling 2 380 kg) were traded at Durban`s Victoria and Isipingo medicinal plant markets during July of 1992 alone.
Growing Stangeria eriopus
From a gardening point of view, Stangeria is a most attractive plant with its large fern-like leaves and is an ideal plant for shady gardens. They are long-lived and require little maintenance once established. Stangeria is also an ideal pot plant provided they are planted in a large container which provides plenty of room for root development. Restricting root development retards the growth of the plant and it tends to struggle.
This species does best in shady areas in a well-drained soil. Planted in a group of three or five will create an attractive large group featuring their large, fern-like leaves. Suitable companion plants would be are Plectranthus species, Scadoxus multiflorus subsp. Katharinae, Clivia miniata, C. gardenia, C. caulescens and Crinum moorei. When planting a group of Stangeria, space them one metre apart, adding plenty of mature compost and bonemeal in the hole before planting. To maintain a healthy plant, regular feeding is essential. A 50 mm layer of well-matured compost applied as a mulch in the autumn helps to improve the soil and benefits the plants. In early spring apply a mixture of bonemeal, organic fertilizer and a balanced inorganic fertilizer to each plant.
High pressure irrigation systems which produce a strong jet of water will destroy those beautiful leaves; Stangeria will be better suited to rather use an irrigation system which provides a gentle application of water.
The only pests which I have encountered which is detrimental to Stangeria are mealybugs. They need to be sprayed with a systemic insecticide.
Propagation of Stangeria eriopus can be achieved by sowing seed or by rooting leaf stem cuttings. Provided both male and female plants are planted in a group, they will be pollinated by insects or wind and viable seed will be produced. As the female cone begins to disintegrate, the seed should be harvested. Place the seed in water for a day and then remove all of the soft tissue. The clean seeds are then stored in a cool, dry place until the following spring when it is sown on a bed of clean coarse sand which has a bottom heat of 25-28°C. The seeds are pushed into the sand so as that they are level with the surface of the sand. Water each day and within two months the seeds begin to germinate by producing a root followed by leaves. Within10 months the seedlings are removed and potted into a 3 litre plastic sleeve containing a well-drained growing medium which contains some agricultural lime. The seedlings are watered sparingly until they show signs of growth. Within a year these seedlings need to be repotted into 30 cm pots to encourage the plants to develop. Keeping Stangeria in small containers prevents them from growing. Once in the open ground they develop well.
To produce plants from cuttings, an entire leaf needs to be broken off the stem of the plant. This ensures that a portion of stem is attached to the base of the cutting which is essential for rooting. The leaf itself is trimmed back to prevent loss of moisture. The base of the cutting is treated with a rooting hormone and placed in a rooting medium of clean, coarse sand at a depth of 8 cm. Within 10-14 weeks, callus and root development occurs and after 18 months a well-developed root system is established.
References and further reading
- Crouch, N.R., Donaldson, J., Smith, G.F., Symmonds, R., Dalzell, C.G.M. & Scott-Shaw, C.R. 2000. Ex situ conservation of Stangeria eriopus (Stangeriaceae ) at the Durban Botanic Gardens, South Africa. Encephalartos 63: 16-24. The Cycad Society of South Africa.
- Douwes, E., Gillmer, M., Mattson, M. & Dalzell, C. 2004. Vegetative propagation of Stangeria eriopus from leaf material. Encephalartos 80:28-30. The Cycad Society of South Africa.
- Giddy, C. 1984. Cycads of South Africa. Struik, Cape Town.
- Vorster, P. & Vorster, E. 1985. Stangeria eriopus. Encephalartos 2: 8-17. The Cycad Society of South Africa.
Kirstenbosch Botanic Garden