Haworthia marumiana var. marumiana
Haworthia marumiana Uitewaal var. marumiana
Family: Asphodelaceae
Common names: Karoo cliff haworthia (Eng.), karroo-dwergaalwyntjie (Afr.)
Introduction
Haworthia marumiana var. marumiana is a dwarf plant with numerous rosettes of dark green, ovate-lanceolate, succulent leaves that hug the cliffs in the mountains of the Great Escarpment near Graaff-Reinet in the Eastern Cape. It flowers in summer, when a solitary inflorescence bearing white flowers appears. Best grown in containers.
Fig. 1. A close-up of the rosettes of the Haworthia marumiana var. marumiana, during the dry season, on a farm near Cradock, Eastern Cape.
Description
Description
The plants are stemless, rosulate succulents up to 30 mm in diameter, proliferating from the base to form large clusters. The leaves about 20 × 8 mm, ascending (outer spreading), dark to brownish-green, flattened, ovate-lanceolate, the upper surface flat to subconvex and the lower surface convex with centric keel towards tip. Both surfaces with 3–6 translucent, longitudinal lines, the margin and keel with soft spines, leaf tips tapering to a needle-like hair (aristate). The inflorescence is an erect raceme up to about 230 mm long. The flowers are about 10, the pedicels up to 3 mm long, ascending and the white corolla up to 11 mm long, the floral tube compressed at the base, 4 mm long, curved and funnel-shaped. The segments are free, with green keels, bilabiate, the upper segments erect, slightly recurved. The stamens 7–8 mm long. Ovary 4 mm long; style 1 mm long, white, not capitate. Flowering occurs mainly in summer (January and February, southern hemisphere).
Fig. 2. A cluster of Haworthia marumiana var. marumiana growing in a sandstone cliff crevice on a farm near Cradock, the plants are coming into flower.
Conservation Status
Status
Confined to the mountains of the Great Escarpment near Graaff-Reinet in the Eastern Cape, this species is well protected by its sheer cliff-face habitat that falls within a greater conservation region, consequently, it is not at risk of extinction.
Fig. 3. The mudstone cliffs on a farm near Cradock, Eastern Cape, habitat of Haworthia marumiana var. marumiana, and a close-up of a large, mat-forming cluster growing on the cliff.
Distribution and habitat
Distribution description
Widely distributed in the Great Karoo, it is also found further north beyond the Escarpment mountains to Queenstown in the east, southwards to Willowmore and westwards to Beaufort West, at an altitude of 1 300–2 000 m. The habitat consists mainly of south-facing cliffs, where plants grow firmly rooted in crevices, and size of the plants often depends on the growing space allowed by the crevice. Temperatures are high in summer (35–40°C). Winters are cooler but frost is absent or limited to flat terrain. The average annual daily maximum temperature is about 24°C and the average annual daily minimum temperature about 10°C. Rainfall occurs throughout the year but with a peak in spring and summer, 300–400 mm per annum in the form of thunder showers or cyclonic winter rain.
The associated vegetation consists of Grootrivier Quartzite Fynbos of the Fynbos Biome as well as Camdebo Escarpment Thicket of the Albany Thicket Biome (Mucina et al. 2005). The companion plants on the cliffs on the farm Altydsomer near Cradock include a species of Delosperma, a species of Aizoon and Haworthiopsis tesselata.
The geology consists of Beaufort shales, Adelaide Subgroup (Karoo Supergroup). The substrate has many ledges, crevices and fissures, ideal for the establishment of plants.
Derivation of name and historical aspects
History
Haworthia marumiana was named by the Dutchman Uitewaal in Cactussen en Vetplanten (1940). The name honours Dr M. van Marum.
Haworthia marumiana var. marumiana resembles H. monticola, another small cliff-dwelling plant from near Willowmore. Haworthia marumiana var. batesiana is also related but lacks the soft spines on the leaf margins of H. marumiana var. marumiana.
Fig. 4. A large rounded cluster of the Haworthia marumiana var. marumiana growing on a sandstone cliff-face growing in its native habitat on a cliff near Cradock in the Eastern Cape.
Ecology
Ecology
During dry conditions, the rosettes become incurved. The leaves are dark to lighter green, becoming purplish during dry periods as the plants aestivate, blocking out excessive light and reducing photosynthesis.
The plants are long-lived, with soft leaves withering from the base. The fleshy leaves becomes turgid after rain, and are channelled during dry periods, an adaptation to the extreme, dry cliff habitat.
The inflorescence is ascending to spreading. The white corolla, attracts the right pollinating flying insect. The seeds ripen during summer and autumn, and are shaken from the capsule by wind. The small angular seeds are ideal for establishment in crevices.
Haworthia marumiana var. marumiana suckers freely from the base, forming dense, rounded clusters. Continual sprouting from the base represents an efficient vegetative backup dispersal strategy for this harsh cliff-face environment. Detached clusters or heads will also root if they fall into a crevice.
Fig. 5. A close-up of the base of a large cluster of Haworthia marumiana var. marumiana.
Uses
Use
No cultural or medicinal uses have been recorded.
Growing Haworthia marumiana var. marumiana
Grow
Plants grow well in cultivation but, like most haworthias, they are best kept in pots. Grow in a sandy, well-drained medium as is found in its natural habitat. Keep partially shaded. Feed with an organic fertiliser during spring and summer and water sparingly in summer. Outside its habitat, it is best suited to a greenhouse where conditions can be controlled.
Plants soon proliferate and are best propagated by division. Divide the plants in spring or summer and plant in a shallow tray in a sandy mixture (e.g. peat, sand and polystyrene) and keep moist. Rooting occurs within 3 weeks and once well rooted transfer to individual containers and place the containers in a shady position but with full light. The south side of a building is ideal.
Sow seed in spring, summer or autumn in a sandy medium. First moisten the substrate with fine rose. Cover the seed lightly with a thin layer of sand. Keep moist and in a shady position. Germination usually occurs within 3 weeks and the young seedlings are relatively fast growing. Transplant the seedlings to individual containers once large enough to handle.
Plants are relatively disease free but aphids, slugs and snails can sometimes be a problem.
References
- Bayer, M.B. 1999. Haworthia revisited, a revision of the genus. Umdaus Press, Hatfield.
- Bayer, M.B. & Van Jaarsveld, E.J. 2001. Haworthia. In U. Eggli. (ed.), Illustrated handbook of succulent plants: Monocotyledons. Springer, Berlin.
- Mucina, L. & Rutherford, M.C. (eds) 2006. The vegetation of South Africa, Lesotho and Swaziland. Strelitzia 19. South African National Biodiversity Institute, Pretoria.
- Scott, C.L. 1968. A new species of Haworthia. Journal of South African Botany 34: 1.
- Van Jaarsveld, E.J. & Forster, P.I. 2001. Bulbine. In U. Eggli, Sukkulenten Lexicon (Band 1). Einkeimblattrige Pflanzen (Monocotyledonen). Ulmer, Stuttgart.
- Uitewaal, A.J.A. 1948. Haworthia batesiana Uitewaal sp. nov. The National Cactus & Succulent Journal 3(4): 101.
Credits
Ernst van Jaarsveld
Kirstenbosch National Botanical Garden (Retired 2015)
Babylonstoren Farm
Extraordinary senior lecturer and researcher,
Department of Biodiversity and Conservation, University of the Western Cape
January 2022
Plant Attributes:
Plant Type: Succulent
SA Distribution: Eastern Cape
Soil type: Sandy
Flowering season: Late Summer
PH: Acid
Flower colour: White
Aspect: Morning Sun (Semi Shade), Afternoon Sun (Semi Shade)
Gardening skill: Easy
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