Microloma

Microloma
Microloma
Microloma tenuifolium inflorescence.
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Gentianales
Family: Apocynaceae
Subfamily: Asclepiadoideae
Tribe: Asclepiadeae
Subtribe: Astephaninae
Genus: Microloma
Robert Brown (botanist) [1]
Type species
Microloma sagittatum (Ceropegia sagittata, Linn. mant.)
L.

Microloma R. Br. in Mem. Werner. Soc.1: 53, (1809), is a genus of some ten or twenty known species of herbaceous perennial, dicotyledonous plants . Microloma species were originally described as members of the genus Ceropegia, in the family Asclepiadaceae, but Brown separated them and created the new genus, still in the family Asclepiadaceae.[1] More recently the Asclepiadaceae have been re-classified as the subfamily Asclepiadoideae of the dogbane family Apocynaceae.

Microloma tenuifolium growing in a tangle without support where fire had removed fynbos scrub a year earlier. Usually the stems would be twining around the branches of perennials.

Common names of Microloma species are various and regional; Manning mentions "wax creeper" and "melktou" (literally "milk-string", a curious name because the plants do not in general produce latex).[2] Other names include "wax twiner" and "bokhorinkies" (literally "little goat- or antelope-horns, a reference to the shape of the fruit). Marloth said: "The Dutch name is, as the flower produces so much nectar that in the morning one may shake out a drop of it from each flower." [3] "Suikerkannetje" means little "sugar-can". Marloth adds:"In spite of this proffered feast, visitors are rare and one must have much patience if one wants to know who the visitors are that respond to the invitation — they are small moths and tiny butterflies like the Lycaena or still smaller kinds." More recent work however has shown that such insects are incidental visitors; the main pollinators are sunbirds; they the pollinia stick to their tongues in a striking example of specialised mutualism.[2]

Microlomas are perennials. Some are climbers and some are shrublets; Microloma massonii (now = Microloma armatum) is so densely branched, with the branches so spiny at their tips, that the colloquial name is "ystervarkbossie", meaning "porcupine bush".[4] Unlike many of the Asclepiadoideae Microlomas have clear sap. Their leaves are opposite, usually sessile and simple.[2] The inflorescences are umbel-like cymes, borne outside the axils. The flowers usually are red or reddish, sometimes yellow, orange or pink. There are five sepals, with the corolla usually longer than the calyx. The five petals are usually glossily waxy, consistently with some of the common names. The corolla tube is usually pentagonal and urn-shaped or oblong, with tufts of downward-pointing hairs low down in the tube opposite the lobes. The petals are arranged spirally and practically close the tube. The stamens arise from the base of the corolla. The anthers generally are sagittate at their bases, and bear pollinia.[5]

Most species grow a fascicle of fleshy roots around the base of the stem and thus may shed shoots and leaves in dry seasons or when fires pass over.[3] An infusion of the fleshy root fascicle of Microloma saggittatum has been used in traditional medicine for relief of griping pains in the abdomen. The infusion is red in colour. If water is unavailable the patient may chew a piece of the root instead.[6]

Species

Genus: Microloma R. Br.[7]

  • Microloma armatum (Thunb.) Schltr.
  • Microloma burchellii N.E. Br.
  • Microloma calycinum E. Mey.
  • Microloma campanulatum Wanntorp
  • Microloma dregei (E. Mey.) Wanntorp
  • Microloma gibbosum N.E. Br.
  • Microloma glabratum E. Mey.
  • Microloma hereroense Wanntorp
  • Microloma hystricoides Wanntorp
  • Microloma incanum Decne.
  • Microloma lanatum Wanntorp
  • Microloma longitubum Schltr.
  • Microloma namaquense H. Bol.
  • Microloma penicillatum Schltr.
  • Microloma poicilanthum Huber
  • Microloma sagittatum (L.) R. Br.
  • Microloma schaferi Dinter
  • Microloma spinosum N.E. Br.
  • Microloma tenuifolium (L.) K. Schum.
  • Microloma viridiflorum N.E. Br.

References

  1. ^ a b Brown, Robert; The Miscellaneous Botanical Works of Robert Brown Vol. II.; Published for the Ray Society 1867. [1]
  2. ^ a b c Manning, John (2008). Field Guide to Fynbos. Cape Town: Struik Publishers. ISBN 9781770072657. 
  3. ^ a b Marloth, Rudolf. “The Flora of South Africa” 1932 Pub. Capetown: Darter Bros. London: Wheldon & Wesley.
  4. ^ Hobson, Nigel (1975). Veld Plants of Southern Africa. Johannesburg: Macmillan South Africa. ISBN 0869540130. 
  5. ^ Dyer, R. Allen, “The Genera of Southern African Flowering Plants”. ISBN 0 621 02854 1, 1975
  6. ^ Watt, John Mitchell; Breyer-Brandwijk, Maria Gerdina: The Medicinal and Poisonous Plants of Southern and Eastern Africa 2nd ed Pub. E & S Livingstone 1962
  7. ^ Arnold T.H., de Wet B.C. (Eds), Plants of Southern Africa: Names & Distribution, MEMOIRS OF THE BOTANICAL SURVEY OF SOUTH AFRICA No. 62, Pub.National Botanical Institute, South Africa.1993 ISBN 1-874907-03-X



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