Gasteria pillansii is the only true winter rainfall species of the genus. It is easily grown in containers in a shady spot, but has to be kept dry during summer months and it prefers shade. It is an ideal water-wise garden plant for dry, succulent karoo gardens.
Gasteria pillansii is stemless, 50-200 X 60-400 mm, proliferating from subterranean stolons and forming dense clusters, up to 150 plants per group and up to 1 m wide. Roots are succulent. The leaves are fleshy, especially after rain, in two opposite rows (distichous), 20-200 mm long and 15-50 mm broad at the base, and are strap-shaped (lorate), ascending to spreading. The leaves are mottled with white spots in transverse bands, and a white cartilaginous tuberculate margin. The hard, leathery leaf tip is rounded.
The inflorescence is a simple, spreading raceme (1-3 per plant), 0.06-1.2(1.65) m long and rarely with a pair of side branches. The flowers, rich in nectar, 25-45 (50) x 6-8 mm, are pendent on flexible flower stalks (9-20 mm); the tubular flowers, slightly swollen at the base, are laxly arranged and all pointing in the same direction (12-40 per raceme). The ovary is 6-8 mm long with a style 18-25(30) mm long, bearing a minute stigma. After fertilization the pedicle becomes hardened and turns upwards. The fruiting capsule is oblong, 15-23 x 7 mm, loculicidal, opening at the margins. The seeds are 4-5 x 2.5 mm. Flowering time: November to April.
Gasteria pillansii is common in many parts of Namaqualand, thus not threatened.
Distribution and Habitat
Gasteria pillansii is endemic to the dry winter rainfall region in a 100-150 km belt parallel to the west coast from just south of Clanwilliam, South Africa, to just north of the Orange River in southern Namibia, occurring in Succulent Karoo vegetation. It is found at elevations from close to sea level to about 1 000 m on the Namaqualand escarpment, mainly confined to the cooler southern and eastern aspects, underneath shrubs or shrublets or in the shade of rocks, rarely in exposed or north-facing aspects.
There is a distribution gap on the Knersvlakte between Vanrhynsdorp and Nuwerus. The rainfall, occurring from April to September, ranges from 25-200 mm per annum. Heavy fog from the Benguella Current (Atlantic Ocean) provides additional moisture. Light frost may occur in the area. Summers are very hot with temperatures often reaching 40º C. It grows on various rock and soil formations, but more commonly on sandstone, granite and shale. The soils are sandy and well drained with a pH of between 6.2 and 7.8.
Populations south of Clanwilliam occur on flat, rocky, sandstone ridges in the shade of Diospyros ramulosa and Montinia caryophyllacea. Other commonly associated succulent species in the habitat include Ruschia rariflora, Lampranthus thermarum, Tylecodon paniculatus, T. reticulatus, Cotyledon orbiculata, Prenia pallens and Stapelia hirsuta.
There is a marked vegetative resemblance to Gasteria disticha of the southern Great Karoo and Breede River Valley, which has similar leaves but G. disticha has smaller flowers of only 12-20 mm in length and the base of the flowers is markedly swollen (gasteriform) for about two-thirds of its length. In floral characters G. pillansii may be confused with G. acinacifolia, G. croucheri and G. batesiana from the eastern Lowveld regions of South Africa, but they are quite different, having leaves that are keeled and are arranged in a rosette. These species have a somewhat similar large perianth but G. pillansii differs from them in that its perianth has a swollen basal part for less than a third of its length.
Gasteria pillansii is very variable especially in leaf and perianth size. Towards the coast, near the Olifants River Mouth, the leaves become more markedly rough and covered with sand and dust. This variation is continuous and the small forms (leaves smaller than 70 mm) have been named G. pillansii var. ernesti-ruschii , which occurs near the Port Nolloth coast to southern Namibia.
Plants from the Oograbies Mountains in the Port Nolloth District occur on steep, rocky, southern and eastern aspects in quartzitic rock crevices. Associated plants in the habitat include Tylecodon racemosus, T. similis, T. schaeferianus, Haworthia arachnoidea, Conophytum stephanii, Crassula hemisphaerica, C. columella and various other succulent and geophytic species. A rich succulent flora probably the richest in the world, predominates in the these mountains.
Derivation of name and historical aspects
Gasteria pillansii is one of 20 species of Gasteria which is mainly confined to South Africa and occurs in the northwestern part of Western Cape, Namaqualand and southern Nambia.
Gasteria pillansii was named by Harry Bolus and Louisa Kensit, better known as Louisa Bolus (Bolus & Kensit 1909). It commemorates Mr N.S. Pillans, a botanist from the Bolus Herbarium who collected plants near Clanwilliam ( Pillans 833 ) and grew this plant in his garden in Rosebank, Cape Town. However, it was known much earlier: there is an early illustration of G. pillansii which is probably the work of Claudius who accompanied Olaf Bergh on his expedition to Namaqualand from 27 August to 24 October, 1683. A reproduction of this early illustration appeared in the 1967 catalogue of pictures in the Africana Museum in Johannesburg.
The smaller Gasteria pillansii var. ernesti - ruschii as named by Kurt Dinter (1938) from plants collected in southern Namibia near Lorelei Mine by Ernest Rusch, a Namibian farmer.
Gasteria pillansii is pollinated by sunbirds. Its fruiting capsules becoming erect after fertilization, opening from the top only to release t he flattish seeds which are dispersed by gusts of wind. thus ensuring a sufficient dispersal distance. The fleshy leaves store water and are drought tolerant.
Uses and cultural aspects
Gasterias pillansii is not used medicinally.
Growing Gasteria pillansii
Gasteria pillansii is easily propagated from leaf cuttings or seed. It grows relatively fast, and is a long-lived species. The leaves should first be allowed to dry and heal on a cool window sill for at least three weeks. Treat the basal part with a fungicide. Plant the leaves in an erect position or lying on their side 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 protected from full sun. The seedlings are slow growing and can be planted out in small containers when they are large enough to handle. The soil should be enriched with compost; they react very well to a liquid organic fertilizer. G. pillansii is a winter growing species and should be kept dry during the summer months.
The following cultivars are recommended:
- 'Clanwilliam': introduced from Clanwilliam with leaves up to 200 mm long and the perianth up to 50 mm long.
- 'Krakadou': a natural mutation with an amalgamation of the leaf spots was found in a normal population south of Clanwilliam; the leaves are whitish green.
- 'Vredendal': near Vredendal, Mr Anthony Mitchell collected an aberrant form with tuberculed leaves.
- 'Rosyntjiesberg': a form with broad, short leaves found in the Richtersveld by the author,
References and further reading
- Bolus, H. & Kensit, Louisa, 1909. Contributions to the African Flora: Gasteria pillansii., Kensit, n. sp. . Transactions of the Royal Society of South Africa 1: 163.
- Kennedy, R.F. 1967. Cataloque of pictures in the Africana museum Vol 2, 307-738. Africana Museum , Johannnesburg.
- Von Poellnitz, K. & Dinter, K. 1938. Die erste Gasteria-art aus Sudwestafrika. Gasteria ernesti-ruschii Dinter et von Poellnitz spec. nov. Kakteen und Andere Sukkulenten, 63: 239.
- Van Jaarsveld, E.J. 1994. Gasterias of South Africa. Fernwood Press, Cape Town.
Ernst van Jaarsveld
Kirstenboch National Botanical Garden