A Plant that has always been Rare

Borya mirabilis is a small, clumped lily with clusters of stiff, narrow leaves and white flowers borne at the ends of slender, upright stalks.  It is known from a single locality - slightly more than a hectare - in rocky terrain of the Grampians National Park in western Victoria.  The vegetation which supports Borya is a shrubland with occasional mallee-form trees and a range of small annual, ephemeral and perennial herbs in the understory.

Borya mirabilis was first discovered, in the Grampians, in 1924, at which time it was regarded as a very isolated occurrence of the Western Australian species, Borya nitida. A second collection was made in 1952, from the same site in the Grampians, but after that time the species seemed to vanish. Many competent botanists went looking for it, in the place the specimen was supposed to have been collected, but no one could find it.  There was, of course, speculation that the species had become extinct. However, there was also a suspicion amongst some botanists that the record was a hoax and that Borya had never been in the Grampians in the first place - after all it was a very long way from Western Australia.

All that changed in 1981. At that time a botanist, who was also a teacher, decided that it was time to determine definitively whether Borya was indeed in the Grampians. His approach was simple, he took a class of students on a field trip to the site where Borya had been recorded, mapped a rectangular grid over the site and a generous area around it, and then he and his students conducted a thorough and systematic search.  Every square metre of ground on the grid was examined, which was just as well, for when Borya was re-discovered it was found to occupy only a few square metres in total.

Once Borya was collected, and living specimens taken back to the Royal Botanic Gardens, taxonomic examination determined that it was not the Western Australian Borya nitida, but a new species unique to Victoria.

Borya mirabilis is one of a group of herbs commonly called resurrection plants. They have this name because during times of water shortage and drought their leaves change from green to become dry and straw-coloured - they look and act as if they were dead. This is not uncommon amongst plants that live in relatively dry or exposed areas, but in most plants the straw-coloured leaves are indeed dead, so that new ones must grow next season. Resurrection plants, however, keep their dry leaves, which simply turn green again when the weather becomes cooler and wetter.  In the case of Borya mirabilis the leaves turn straw-coloured in summer (usually December) and become green again in autumn.

This is a wonderful adaptation to life in an exposed, often dry and very nutrient-poor environment but it really doesn't seem to do Borya much good as the species hasn't increased its abundance from the few square metres it now occupies. The reason for this lies perhaps, in the fact that Borya mirabilis is not able to set seed - at least none have been found in the wild nor have any been formed in cultivation.  Recent research has also suggested that all plants so far discovered are genetically the same and unable to reproduce by sexual means, therefore any reproduction in the wild (or in cultivation) will be vegetative.

From a conservation perspective this probably means that Borya mirabilis is on the edge of extinction.  A tiny population is always prone to catastrophic local accidents.  A genetically uniform species is prone to being wiped out by a single disease or by the same kind of stress. And any species that cannot produce seed has reached an evolutionary end point.