Common name: He Cabbage
Scientific name:Pladaroxylon Leucodendron
IUCN status: Critically endangered
Natural History
The he cabbage is now very rare on the island but was once bundant amongst the cabbage tree woodland, growing alongside whitewoods and she cebbages. The few trees tht survive today cn be found growing within the Diana's Peak National Park and at High Peak.
The cabbage tree woodland was largely cleared to make way for pasture land and later New Zealand flax plantations. Less than 100 trees now survive and these are distributed between nine different locations within Diana's National Park and the High Peak population.
Isolation of the different populations presents a threat to the future survival of the he cabbage. As only a few individuals survive in any one location there is a high probability that these populations will become extinct. Not only are they threatened by poor seed viability/poor regeneration and inseed predation, but in many places the trees are mature or senile. The loss of these individuals is inevitable and this means that the numbers in each location will continue to decline because they are not beeing replaced by young trees. Inbreeding, the mating of close relatives, could also cause the decline in fitness of the populations because the differnet populations are reproductively isolated from each other.
DESCRIPTION
The he cabbage is a small spreading tree growing up to 3-4m in height with grey-green bark. The leaves are clustered towards the end of each branch and are very variable in size, growing up to about 0.3m in length. The leaves are pale green and rougher than those of the black cabbage and have slightly toothed edges with very prominent veins.
The white composite flowers form terminal clusters on the branches, resembling the head of a cauliflower. Flowers appear from June to August.
NUMBER OF SURVIVING POPULATIONS
There are only nine surviving populations of the he cabbage within the National Park. The numbers in each population range from one individual to 35. A few he cabbage trees can be found at High Peak. However, there is very little evidence of natural regeneration for most of the populations. The largest population of 35 individuals doea have a mixture of age ranges including young seedlings.
CONSERVATION RECOVERY PROGRAMMES
Under the National Park Management Plan, he cabbages are being planted out in several locations across the Peaks. Seed is collected annually, the seed raised at the nursery at Scotland and the seedlings then used in the Peaks plantings. Efforts are also being made to collect cuttings from a wide range of individuals. These cuttings, as well as seed, will be included in a seed orchard which is currently being set up in the Diana's Peak National Park.