For the identification of insects and other fauna and flora of South Africa: please click on the following links:
Insects and related species: Antlions - Ants - Bees - Beetles - Bugs - Butterflies, Moths and Caterpillars - Centipedes and Millipedes - Cockroaches - Crickets - Dragonflies and Damselflies - Grasshoppers and Katydids - Mantis - Stick Insects - Ticks and Mites - Wasps - Woodlice
Plants, Trees, Flowers: (Note: Unless plants fall into a specific species such as Cacti, they have been classified by their flower colour to make them easier to find) Bonsai - Cacti, Succulents, Aloes, Euplorbia - Ferns and Cycads - Flowers - Fungi, Lichen and Moss - Grass - Trees
Animals, Birds, Reptiles etc.: Animals, Birds, Fish and Crabs - Frogs - Lizards - Scorpions - Snails and Slugs - Snakes - Spiders - Tortoise, Turtles and Terrapins - Whipscorpions
Other photography: Aeroplanes - Cars and Bikes - Travel - Sunrise - Water drops/falls - Sudwala and Sterkfontein Caves etc.

Friday, October 17, 2014

Karoo Blue Tulip (Morea polystachya)

Family Iridaceae
Distribution and HabitatMoraea polystachya is widespread in central South Africa and Namibia, but its range overlaps that of M. venenata in Namibia and Northern Cape, South Africa. The average annual rainfall ranges from 100 to 700 mm, and is probably considerably less in a 'normal' year. In part of their common range, the sparse rainfall occurs in summer, while the remainder of the range receives rain in winter. The habitat is well-drained flats and slight slopes, with collectors often referring to the presence of calcrete deposits. Light frost occurs, but in mid-summer (when the plants are dormant) the temperatures may regularly exceed 40ยบ C.
EcologyAs mentioned above, in the northern part of the common range, the plants flower mainly in autumn (March to May), but in the south, flowering is more usual in winter (June to August) or even spring (September, October). The complex style structure is known to be specifically adapted for bee pollination, but unfortunately no specific observations on these two species are available.

The plants are thought to increase in number due to overstocking of grazing land. It is interesting that stock animals born and raised in lands infested with these plants are able to recognize and avoid them. Cattle deaths often occur in the winter months when there is no other fresh grazing available. The dried plant material is also toxic and when accidentally incorporated in hay can have disastrous results. A few cases of fatal human poisoning have been reported, where the corms were mistaken for those of edible species, such as Moraea fugax. The toxin has been identified as a cardiac glycoside (heart-poison).
Uses and cultural aspectsOne label attached to a herbarium specimen reports that the 'Hottentots plait the leaves into mats' but this information has not been confirmed elsewhere.

The two species are economically important due to their toxicity. Southern Africa abounds in toxic plants and much time and energy has been devoted to identifying the plants and their toxins by such government organizations as the Veterinary Research Institute at Onderstepoort, Pretoria.