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Origin and Habitat: Haworthia koelmaniorum var. mcmurtryi was described near Loskop Dam and now it is known from several localities around the highveld areas of Mpumalanga Province.
Habitat: Haworthia koelmaniorum var. mcmurtryi is found on hilly grassland, mostly on rhyolite rocks, both on exposed places or on the shade of grasses. This rock type forms fissures and cavities that are quite often only slightly elevated above the ground. The rosettes are normally flush and well camouflaged with the soil surface and are extremely cryptic. These plants are difficult to spot in their natural habitat. In times of severe drought, the whole above-ground portion of these plants can shrink and be covered by dust and dead leaves, but the swollen succulent roots remains alive. These Haworthias appear to represent an extreme adaptation to regular fires. Their small size and very retuse habit render them almost immune to the effects of grass fires. The retuse leaved “mcmurtryi” were simply adaptations to a fire driven ecology under circumstances where longer leaved haworthias, the typical “koelmaniorum”, would not be able to survive frequent dry season grass fires. Dry grass is highly flammable and burns right down to ground level in fires, unless these are driven by high winds. In such instances the burns are more superficial However fires have little effect on these plants and improve the conditions for the germination of seeds in summers directly after a winter grass fire. Habitats are degraded via the exclusion of fires, by livestock and expansion of rural settlements.
- Haworthia koelmaniorum var. mcmurtryi (C.L.Scott) M.B.Bayer
Haworthia koelmaniorum var. mcmurtryi (C.L.Scott) M.B.Bayer
Haworthia Revisited 181 (1999)
- Haworthia koelmaniorum var. mcmurtryi (C.L.Scott) M.B.Bayer
Haworthia koelmaniorum Oberm. & D.S.Hardy
Fl. Aegypt.-Arab. xxxviii. t. 1502 (1967)
- Haworthia koelmaniorum Oberm. & D.S.Hardy
Description: Haworthia koelmaniorum var. mcmurtryi is a smaller relative of Haworthia koelmaniorum. It is a dwarfer compact plant with more prominent nodular surface markings, that somewhat resembles a reptile's skin. Leaves are shorter, more retuse, and can be obscurely windowed. It is quite variable regarding tubercles and venation and in most colonies typical shorter leaved plants as well as some long leaved examples are found. The latter are often indistinguishable in appearance from typical Haworthia koelmaniorum.
Habit: Usually solitary when growing in exposed places, but in deep shade it tends to offset, forming clumps.
Rosettes: Stemless, smaller than in Haworthia koelmaniorum and reaching only a diameter up to 5 cm, but mostly 2 x 2 cms in size, some even less.
Leaves: Ovate, 2,5 cm long, 1-2 cm broad, scabrid, with more prominent, raised tubercles, opaque, dark brownish-green, tan, reddish or grey or some thing in between, somewhat recurved, margins and keel with small spines.
Inflorescence: Slender, wiry to 35 cm tall. H. koelmaniorum var. mcmurtryi nearly always produces a single flowering stem. (Haworthia koelmaniorum often grows more than one flower stem in a given flowering season usually 2 – 3)
Flowers: 10-15, slender, tepal-tips revolute.
Subspecies, varieties, forms and cultivars of plants belonging to the Haworthia koelmaniorum group
- Haworthia koelmaniorum Oberm. & D.S.Hardy: ia a slowly growing species characterized by dark brownish-green, leaves, with thick, leathery, nodular skin on them, that somewhat resembles a reptile's skin. Distribution: around Groblersdal and Loskop Dam in Transvaal.
- Haworthia koelmaniorum var. mcmurtryi (C.L.Scott) M.B.Bayer: It is smaller in size with more prominent surface markings. Leaves are shorter, more squatter and can be obscurely windowed. Distribution: endemic to the highveld areas of Mpumalanga Province.
Bibliography: Major refetrences and further lectures
1) Urs Eggli “Illustrated Handbook of Succulent Plants: Monocotyledons” Springer, 01/gen/2001
2) M. B. Bayer “The new Haworthia handbook” National Botanic Gardens of South Africa, 1982
3) John Pilbeam “Haworthia and Astroloba: A Collector's Guide” 1983
4) Stuart Max Walters, James Cullen “The European Garden Flora: Pteridophyta, Gymnospermae, Angiospermae” Cambridge University Press, 1986
5) David Hardy, Anita Fabian, Gerrit Germishuizen “Succulents of the Transvaal” Southern Book Publishers, 1992
6) Keith Grantham, Paul Klaassen “The plantfinder's guide to cacti & other succulents” Timber Press, 18/mag/1999
7) E. Retief, P. P. J. Herman “Plants of the northern provinces of South Africa: keys and diagnostic characters” National Botanical Institute, 1997
9) Bruce Bayer. "Haworthia Revisited. A revision of the Genus", Umdaus Press, Hatfield, Pretoria, 1999
10) P.T.A. Bosch. "The geological pedalogical and climatical influence on variety generation in Haworthia koelmaniorum variety koelmaniorum and H. koelmaniorum variety mcmurtryi." Aloe 41: 2 and 3, 2004
11) Charles Craib. "The autecology and status of Haworthia koelmaniorum variety mcmurtryi." Aloe 44: 1, 2007
12) Charles Craib. "An evaluation of the two varieties of Haworthia koelmaniorum and a study of the plants in the western part of their distribution range." In. ed. (Full details will be supplied when the paper is published).
13) Amelia Obermeyer. Haworthia koelmaniorum. in: The Flowering Plants of Africa, Volume 38, Plate 1502, 1967, Botanical Research Institute, Pretoria.
14) Charles L. Scott. The Genus Haworthia a taxonomic revision. in : Aloe Books, Johannesburg, 1985
15) Pemroock seeds and plants newsletter September and October 2008
Cultivation and Propagation: Haworthia koelmaniorum var. mcmurtryi is of relatively easy cultivation, but very slow-growing. Haworthias are winter growers and are dormant in the hottest summer months.
Soil: They are tolerant of a wide range of soils and habitats, but prefer a very porous potting mix to increase drainage. A non-acid soil is ideal. You can grow a plant in a small cm pot for years and have perfectly happy plants. For best results, use a shallow pot.
Exposition: The plant needs light shade to shade, but will take full sun part of the day. (with some sun exposure the leaf develops a nice reddish tint and remains compact).
Watering: During the hot summer months, the soil should be kept moist but not overly wet. During the winter months, water only when the soil becomes completely dry. Wet soil quickly causes root and stem rot, especially during chilly winter months. No water should ever be allowed to stand around the roots. Low ambient humidity is always needed.
Fertilization: The plants are fertilized only once during the growing season with a balanced fertilizer diluted to ½ the recommended strength.
Hardiness: Although the plant will survive mild frost if kept dry (hardy as low as -5° C) it should be protected from severe cold and prolonged frost conditions.
Rot: Rot is only a minor problem with Haworthia if the plants are watered and “aired” correctly. If they are not, fungicides won't help all that much. Care must be given in watering, keeping them warm and wet while growing, and cooler and dry when dormant.
Remarks: Haworthias are best planted in a shaded and airy part of the greenhouse, and not too close to the glass roof or sides of the house as the plants can overheat during hot spells.
Propagation: Haworthia are easily propagated by the removal of offshoots or by leaf cuttings in spring or summer. To propagate by leaf cuttings, remove a leaf and let it lie for about one month, giving the wound time to heal. Then lay the leaf on its side with the basal part buried in the soil. This leaf should root within a month or two, and small plants will form at the leaf base. They can also be grown from seed.
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