Gasteria acinacifolia is the largest of all Gasteria species, strictly coastal and ideal for coastal gardens. It is at once recognized by its large rosette of linear-lanceolate, spotted leaves, flat-topped flowering panicles and large, tubular flowers rich in nectar, attracting sunbirds during spring.
Plants erect or sometimes decumbent rosettes up to 750 mm tall and 650 mm in diameter, solitary or dividing to form small, dense groups. The linear, spear-shaped to strap-shaped, sickle-shaped leaves are up to 600 mm long, 45-100 mm broad at the base. Both surfaces are smooth, dark green, with dense white spots arranged in transverse bands. The whitish margin is firm, leathery, minutely saw-edged, rarely entire and ending in a sharp point. The juvenile leaves are distichous (regularly arranged in two opposite rows, one on each side of the stem), strap-shaped and unlike the adults with a rough texture and a blunt point.
The inflorescence is a simple raceme (flower stalk) at first, becoming flat-topped or ascending-spreading in adult plants and up to 1 m tall. Its flowers are large, tubular, 35-50 mm long; the capsule is 35-43 mm long, truncate or obtuse at the apex. Seeds are 6-8 x 5-6 mm. Flowering time: September to December.
Gasteria acinacifolia is becoming threatened due to urban housing development along the Eastern Cape coast, the habitat of our species.
Distribution and Habitat
Gasteria acinacifolia is one of 21 recognized Gasteria species, all endemic to South Africa and is distributed from Buffels Bay and Knysna (Western Cape) to East London in the east Eastern Cape, occurring on coastal dunes or rocky ridges along the coast. Populations can be seen along the popular Otter Trail of the Tsitsikamma National Park and coastal dunes at Nature's Valley where the plants are often abundant. Just one species, G. pillansii, occurs in Namibia.
It is well suited to coastal gardens where frost is not a problem. Rainfall in its habitat varies from 600-1 000 mm per annum during the winter and summer. The climate is mild and if frost occurs it is a rarity, summers sometimes hot but mostly moderate due to the coastal climate and mild winters. The plants usually grow among dense dune thicket, often in shade but also exposed in full sun. Its brittle leaves, when becoming detached, rapidly root, forming vegetative offshoots. It is thus well adapted to disturbance such as grazing and trampling and the fragmented parts simply re-sprout.
It resembles Gasteria pulchra which has much smaller leaves and an erect inflorescence.
Derivation of name and historical aspects
Gasteria acinacifolia was named by the Europaean botanist Jacquin in 1811, but it is not certain who first brought it into cultivation. It was named from a specimen taken from Holland to Vienna in 1809. This herbarium specimen was destroyed during the Second World War. The specific epithet, acinacifolia, pertains to its sharp, scimitar-shaped leaves.
Gasteria acinacifolia is pollinated by sunbirds. Its large fruiting capsules stand erect and its large winged seeds (largest for the genus) are wind dispersed. Its fleshy leaves store water and it is thus drought tolerant and an ideal water-wise garden plant
Uses and cultural aspects
Gasterias, believed to have magical powers, are popular among the traditional healers. Due to its spotted leaves, it is well camouflaged in nature, so if one is washed with the leaves, it is believed that the user will acquire this camouflage.
Growing Gasteria acinacifolia
Gasteria acinacifolia is easily propagated from leaf cuttings or seed. The leaves should first be allowed to dry and heal and then be placed in a cool area for at least 3 weeks. Preferably treat the basal part with a fungicide. Plant the leaves erect or lying on their sides in sandy soil. Rooting is rapid and young plants can be harvested the following season. Seed should be sown during summer in sandy, well-drained soil and preferably protected from full sun. The seedlings are slow growing and can be planted out in small containers until they are large enough to handle. G. acinacifolia is an ideal plant for difficult coastal gardens and can be grown in full sun or shade. The soil should preferably be enriched with compost.
Companion plants include the kwar (Canthium obovatum), boetabessie (Chrysanthemoides monilifera), cross-berry (Grewia occidentalis), and milkwood (Sideroxylon inerme). Smaller associated species include Protasparagus aethiopicus, Eriocephalus africanus, Pelargonium zonale, Erica speciosa, Cotyledon orbiculata and Crassula orbicularis. It also thrives in containers, but a sandy mixture enriched with compost is advised. It is relatively pest-free, occasionally fungal infection causes dark leaf spots. These can be treated with a fungicide. Snout weevils (Brachycercis monachus) can sometimes be a problem. This can be prevented by using an insecticide during late spring when the weevils are laying eggs.
- Van Jaarsveld, E.J. 1994. Gasterias of South Africa. Fernwood Press, Cape Town
Ernst van Jaarsveld
Kirstenboch National Botanical Garden