This beauty is one of the standout blooms at Verloren Valei despite the fierce competition.
By Gerrit van Ede
When in flower, this orchid is very noticeable in the sour-grass veld of Verloren Valei, and is one of the beauties of the Reserve. Standing up to 700mm high, the bulk of the inflorescence is normally above the grass, and with its pale to darker pink colouring it stands out in the veld. The rarer white form is even more noticeable.
A distinct feature of the flower is the prominent spur that protrudes some 50mm. What is not so noticeable is the green labellum (lip), which is tucked in underneath the other parts of the flower.
The plants tend to occur in damp areas in moist grassland and in pockets among rocks. They will sometimes be found in areas that may seem at first glance to be dry but which, on closer inspection, are found to retain moisture for some reason. However, Disa cooperi does not occur in wet and near-wet areas like the edges of streams or marshes.
This species tends to live in scattered colonies on the Reserve, with a single plant relatively seldom seen. Colonies of 20 or more plants in flower have been observed.
When in flower or bud, this plant has two distinct shoots: one flowering and one sterile, which only puts out leaves. The fertile shoot uses the energy stored in the existing tuber, which then withers away and dies. Meanwhile, the sterile shoot creates the new tuber for next year’s flowering. Many of our terrestrial orchids share this characteristic—a new tuber must be produced each season to ensure the plant survives the dormant period as the previous tuber has been depleted. These orchids rely on some root fungi called mycorrhiza for the germination of the seed and the creation of the new tuber.
Disa cooperi has a fairly narrow flowering window of about three weeks starting normally in the last week of December and ending in mid-January. However, the exact dates of this flowering period may vary from year to year depending on climatic conditions. Some individuals may flower either before the start of the period or after the end of the period.
Disa cooperi is named after Thomas Cooper (1815-1913), an English plant collector who must have been quite active in South Africa, judging by the fact that six plants bear his name.