SA Orchids: Disperis

Disperis thorncroftiiDisperis is a large genus centred in Africa and also ranges into Asia with a few species (India, Thailand, Phillipines, New Guinea). 26 species are found in both rainfall regions in South Africa. Disperis species are slender plants with small to medium-sized flowers and are thus not very conspicuous despite of their sometimes brilliant colours. The plants grow singly or in small groups and are to be found in forest, scrub and grassland. The pollination of Disperis is interesting, and is carried out mainly by specialized bees that collect oil. Flowering is mainly in spring and summer.


The plants are terrestrial with underground root tubers and are 10-50 cm tall. The one to five leaves are mostly cauline (borne on the stem). In case of two leaves these may be alternate or opposite. Inflorescences are rather laxly one- to few-flowered. The small or medium-sized flowers are white, cream, yellow, green or magenta. Their median sepal is usually hooded, but rarely extended into a prominent spur. A remarkable feature of this genus is the spurred lateral sepals. Basally fused to the column, the lip is very variable in shape and has an appendage that may be larger than the lip itself. The column is very complicated, with parts sticking forward (the lateral rostellum arms).

Selected species and their main distribution
Winter-rainfall area: D. villosa ('moederkappie', 'oumakappie'), D. bolusiana, D. cucullata ('witch orchid', 'moederkappie'), D. capensis ('horing moederkappie', 'mombakkiesblom'), D. circumflexa
Summer-rainfall area: D. anthoceros, D. micrantha, D. lindleyana ('granny bonnet'), D. cardiophora, D. stenoplectron, D. tysonii ('witch orchid'), D. fanniniae ('bonnet orchid')
Both areas: D. paludosa ('moederkappie')


Cultivation


The cultivation of plants of this genus is difficult and therefore seldom attempted.

Winter rainfall species

Some Disperis species are from the winter-rainfall region of South Africa and instructions for growing satyriums can be followed. The plants should be planted in a well drained medium in a deep pot (20 - 30 cm deep). A suitable medium would consist of 70 % river sand and 30 % milled pine bark or well-decomposed compost. Decomposed pine needles are also beneficial. If the river sand is fine and compacts too much, 20 % Polystyrene granules or some other inert medium should be added to the river sand to improve aeration. Additionally some compost or leaf mould can be placed in the base of the pot and the rest of the medium on top.

Pots can be kept under 40 % shade. For species from the winter-rainfall region plants should be watered regularly from the time that temperatures start dropping in autumn until mid spring. Gradually increase the intervals between watering until in midsummer (November till end of February), when watering should stop. This is a crucial dormancy period for the plants, over-watering during this period will cause the tubers to rot. The pots should be kept cool and damp enough so as not to dehydrate completely, i.e. not reach permanent wilting point. A handy way of keeping the medium at the available water capacity level is to grow a non-invasive hardy herbaceous indicator plant in the same pot. The indicator plant can be weeded out when the disperis starts to re-grow at the beginning of the new growth season. In the case of disperis, a summer annual would be suitable. As soon as it appears to start wilting, drench the pot. Plunging the pots and placing a mulch of bark nuggets, wood chips, straw or pine needles on top will aid in keeping the tubers cool and prevent excessive dehydration of the medium.


Summer rainfall species

Disperis species from the summer-rainfall region can be cultivated in the same manner as summer- rainfall region species of eulophias. Plants should be planted in a well drained medium in a deep pot under 40 % shade. A suitable medium would be 70 % river sand and 30 % milled pine bark or well-decomposed compost. Additionally some compost or leaf mould can be placed in the base of the pot and the rest of the medium on top. Most of the cultivated disperis from summer rainfall areas are dormant during the winter period. The plants should thus be treated like bulbs and kept on the drier side during the winter season, commencing with watering only once the new shoots appear. Watering in the summer period can be done once or twice a week, depending on dehydration rate of the medium. Feeding is only done during the summer growth season. Fertilisers that have been used successfully are: Nutrisol, Nitrisol, Seagro, Multifeed 10, Osmocote and Horticote.


Click images to enlarge

Disperis paludosa
D. paludosa
Disperis villosa
D. villosa
Disperis cucullata
D. cucullata

D. capensis
Disperis circumflexa
D. circumflexa
Disperis lindleyana
D. lindleyana


Description and images : Hubert Kurzweil and O.Kurze


Cultivation: Hildegard Crous
October 2000


SANBI Home © S A National Biodiversity Institute
Orchids
Copyright