Dryandras are plants of dry heaths, woodlands and forests and, in their natural habitat, are subjected to periodic bushfires. Different species have evolved different mechanisms to cope with the problem of survival and/or regeneration. The Dryandra Study Group newsletters of July 1988 and January 1990 reported some of these mechanisms based on observations by the late Ken Stuckey at his extensive plantation at Millicent, South Australia, which was devastated during the 1983 "Ash Wednesday" fire. These were cultivated rather than naturally occurring plants and Ken wondered whether regeneration and dispersal posed a threat to natural environments.

This is a composite of the two articles and includes minor changes of an editorial nature.

The only dryandras noticed to reshoot from the rootstock initially were D.fraseri, D.obtusa and D.calophylla. Subsequently, I found one or two plants of D.shuttleworthiana that had also re-shot from lignotubers after the fire and had been hidden by faster growing post-fire seedlings. Also a plant of D.vestita was noticed doing the same thing, but it is not at all happy. It never did like our South Australian environment.

It has been of some interest to note the regeneration of various species from seed. The most prolific regeneration has been by D.praemorsa, both the pink and the yellow-flowered forms. Even though there were only about ten or a dozen old plants scattered through the garden, thousands of seedlings appeared and proved to be a problem as they were so thick that they were overcrowding other plant species. In fact we are still cutting them out five years after the fire. The plants removed are used as mulch around other self-sown plants of various species.

The next problem species has been D.formosa and to demonstrate the ability of this species to germinate following wildfire I made a count of the seedlings (two and a half years after the fire) in an area of 6.5 square metres which was the area allotted to one shrub of D.formosa that was originally in a block of 100 shrubs. There were 681 plants! plus eleven D.praemorsa and two Hakea cucculata and one Hakea obliqua. This block of plants has been left intact to see what happens eventually. I expect that a few of the stronger plants will survive and the rest will die off. On another patch of D.formosa that had been planted out for cut flower production, the plants were heavily pruned last year and the prunings were placed around newly planted out seedlings. I have noticed when looking around these plants that there were hundreds of Dryandra seedlings germinating. Perhaps dryandras should be declared noxious weeds!!

".....there were hundreds of Dryandra seedlings germinating. Perhaps dryandras should be declared noxious weeds!!"

I suppose we had about half a dozen plants of various D.pteridifolia forms before the fire. These were all killed by now there are plants scattered hither and yon and having to compete with other self sown shrubs.

One of the results of the fire is that I often find "mystery" plants. One such is a Dryandra with the majority of flowers sessile on the trunk and main branches but the flowers borne at the summit of the upright shrub have stems 30-60cm long (ideal for cut flowers!). Perhaps it is just a hybrid*. Growing near this area before the fire were D.plumosa, D.fraseri, D.mucronulata, D.foliosissima, D.nobilis and D.formosa while about 40m away D.baxteri, D.vestita, D.obtusa, D.calophylla and D.hewardiana formerly grew.

Questions arise when we ponder some aspects of the aftermath of the Ash Wednesday fire. We have witnessed the colossal germination, growth and dispersal potential of some of our native plants when taken into a new habitat and away from their specialised predators. Could they become a problem if inadvertently introduced into some of the reserves and parks, or even into other continents with a similar environment?, especially if that environment has adapted to fire, as fire is well known as an agent for increasing the dispersal of aggressive plant species.

* Subsequently identified as D.formosa x D.nobilis by Margaret Pieroni, the Study Group Leader.