Photographs by Connall Oosterbroek.
The autumn flowering Nerine species from Gauteng, Mpumalanga and the North West Province grow in specific habitat niches. One of them Nerine platypetala is a marginal water plant growing around the moist grassy edges of permanent marshes. It is also found in temporarily inundated depressions which remain damp throughout the later summer months.
Nerine frithii and Nerine rehmanii grow in damp areas at the edges of sheets of exposed rock or else in damp grassy depressions. These areas are usually moist throughout the growing and seeding season. Nerine gracilis grows in similar habitat usually in seepage areas at the edges of sheets of exposed dolerite. These situations usually become inundated during heavy rains in February and March.
There is often no sign of these Nerine species from early to mid-summer if the weather has been hot and dry. Foliage that the plants have produced dies back in hot dry weather but sprouts again within a few days after soaking rains.
Nerine platypetala grows amongst grasses and sedges and as it competes with these plants for growing space, it rarely occurs in huge dense concen-trations. The other species namely N. frithii, N. gracilis and N. rehmanii may become locally plentiful where conditions are suitable. All three species have declined in numbers in recent decades particularly N. gracilis which is likely to dwindle to the point of extinction during the course of this century.
The limited range of habitat occupied by these three species, in regions where they occur, makes them particularly vulnerable to habitat alteration and degradation.
The Leolo Mountains in Sekhukhuneland, a centre of floristic endemism, have numerous seepage areas adjacent to vast sheets of exposed norite rock. This habitat is identical to that occupied by N. gracilis and N. frithii but has not been colonised by a Nerine species. The area is densely populated by an undescribed genus with apparently only one species, related to Tulbaghia.
There is still a possibility that further Nerine species may be discovered and described from remote areas like the Leolo Mountains. Amateur botanists are encouraged to familiarise themselves with described species in order that any novelty can be recognised in the field.
Nerine frithii, N. gracilis and N. rehmanii have declined in numbers in recent
decades. N. gracilis has probably fared the worst owing to extensive habitat degradation on the eastern highveld. Most of the habitat, situated in western Mpumalanga and eastern Gauteng, has been degraded by overgrazing, excessive growth of exotic weeds and elimination of habitats by huge concentrations of exotic kikuyu grass. The plants used to occur in suitable habitat around the Vaal Dam in Gauteng but have not been noticed in this area for some years.
1. Nerine rehmanii photographed in habitat in late February 2003 growing on a rocky ridge in suburbia, east of Johannesburg.
The largest colony of N. gracilis is situated on a farm just within the Gauteng provincial boundary. There are a few smaller colonies on the same farm mostly degraded by weeds and trampling by livestock. The farmer is energetically committed to conserving these plants and a private conservation project has recently been initiated on the farm where the plants occur. This initiative ought to ensure the long-term survival of the species. It is hoped in due course to build boardwalks above a large group of plants to enable plant enthusiasts to view them when in flower.
N. frithii has also declined as a result of habitat destruction and habitat alteration. Much of its habitat in the North West Province has been put under the plough and converted to maize fields. The plants are still, however, found in a few areas in the Zeerust district. In this region they grow near sheets of exposed dolerite in cattle ranching areas. Trampling by livestock is a problem but when grazing animals are moved elsewhere the plants build up their numbers again.
5. Nerine frithii in flower in the Zeerust district of the North West Province.
N. rehmanii used to occur on many of the stony ridges around Johannesburg. It has disappeared from most of these but is still found on some of the ridges east of Johannesburg. The introduction of a new conservation policy in recent times accords these ridges special status. As a result N. rehmanii is likely to survive on some of these ridges surrounded by suburban Johannesburg.
2. Details of Nerine rehmanii flowers photographed in habitat.
Two beautiful forms of N. rehmanii are found on the low ridges of the eastern highveld near Devon and Delmas. The plants found near Delmas are a dwarf form of the species, the smallest known. Those near Devon have a rich lavender bloom to the unopened flower buds. The species is seriously threatened in the eastern highveld by road construction and quarrying activities.
Nerine krigei used to be a common and conspicuous species on the eastern highveld particularly in the Devon and Kinross areas. It has declined at an alarming rate in the last few decades owing to habitat alteration and destruction. The habitat is now heavily trampled and degraded with weeds. If landowners are able to conserve these plants on their property they could increase in numbers, particularly if livestock is kept away from groups of plants at flowering time.
3. Nerine krigei in flower in late February 2003. The few plants remaining in habitat in this area of the eastern highveld are surrounded by dense stands of weeds associated with severe habitat degradation. Habitat degradation has been brought about by overgrazing and trampling by livestock.
Nerine gracilis and Nerine krigei produce huge amounts of seed in good seasons in the wild and this could be used to rehabilitate areas where the plants are declining. Without concerted efforts by the farming community both these species are likely to be extinct by the middle of this century.
It is remarkable how N. gracilis is able to build up its numbers when the causal factors that lead to its decline are checked. A colony near Bethal in Mpumalanga, close to extinction on heavily over grazed veld, has now completely recolonised its habitat. The plants probably now number a few million on an area of about one hectare.
4. Part of the largest remaining colony of Nerine gracilis. This colony is in the process of being afforded formal protection through a private conservation initiative and the efforts of the farmer on whose property the plants are situated.
The photograph was taken in late February 2003, the peak of the flowering season.
Nerine species are easily grown from seeds. Seeds should be harvested at the time when they detach easily from the peduncle. The berries should be kept in a well-ventilated room and placed in cardboard trays until they start to sprout. At this time they should be lightly and evenly scattered over the surface of a bulb growing mixture in deep propagation trays. The ideal mixture consists of a third fine washed river sand, a third sandy ordinary soil and a third loam to which some finely sieved, well-rotted compost has been added. A layer of a few centimetres of small stones should be placed at the bottom of the propagation trays to ensure adequate drainage.
The smaller Nerine species reach flowering size in 3-4 years whereas the larger species such as Nerine krigei usually take 4-5 years to come into flower. The bulbs of all species can be transplanted at the end of their second growing season.
All the Nerine species discussed need to be kept dry in the winter months. They should be well watered in the summer particularly late in the season when they begin to form flower buds and come into flower.
All these Nerines make good container subjects. The bulbs should be allowed to grow undisturbed in the containers for many years, to promote good flowering.
Penrock Seeds and Plants offer seeds, young bulbs and flowering size bulbs of all the species discussed. The details appear on the seed and plant lists which are available on request.