Cathy Houston
In recent years a number of N.O.S.S.A. members interested in field work have been involved in surveys for orchids. These include surveys for individuals as well as government or semi-government organisations.
Late in March this year we undertook an Autumn survey of a forest in the South-East known as The Marshes. As the name suggests the area is well served with swamps as well as forest of Stringybark with sandy soil. Several members met the day before to check some areas in the upper SE. Here in sandy-heath there were two species of Corunastylis in flower, often not very distant from each other, but each favouring different habitats. In the heath were C. aff. rufa in flower and capsule. In mallee open forest C. tepperi had recently commenced flowering.
In areas dominated by granite outcrops were found Eriochilus cucullatus flowering and perhaps another un-described Eriochilus species. Leaves were not present, so no distinction could be made from flowers alone. However, in mallee the flowers were larger and supported on much taller stems. Those on the granite were small flowered on short stem, there being no apparent difference in the flowers themselves. Here also the C. aff. rufa was seen in flower and capsule.
In the lower SE a sojourn into Honans Native Forest Reserve produced yet different species, some in flower. C. ciliata was already in capsule, the distinctive greenish-yellow lateral sepals still evident and under magnification hairs could be detected on the labellum. C. despectans had the very last flowers on the top of the scape as well as capsules on earlier flowering specimens. Speculantha obesa had just commenced flowering. In most cases the inward facing, smallish flowers had only the bottom one open with buds on the stem above. Rosettes were not yet present. We were amazed to find Pterostylis nutans rosettes already emerging. A little less surprising was Leporella fimbriata, but the number of flowers seen at this early stage was few.
The Marshes is not renowned for being prolific in Autumn flowering orchids but our visit was scheduled to try to locate as many as we could. By the second day we were rewarded with the discovery of plenty of Spiranthes alticola, which were represented in most of the swamps in the western sector. It is interesting to note that years ago they were found prolifically in the eastern sector but this appears to have dried out too much for them these days. S. obesa was found in very low numbers and this time one of the plants already had a capsule.
Perhaps the greatest excitement was afforded when two members thought they found Cryptostylis subulata leaves. All the surveyors collected for lunch and soon were down at the site considering if the leaves lived up to the name. Much discussion ensued. If only there was a flower to confirm the diagnosis. After what seemed like an age a “tired” flower was located! C. despectans had previously been recorded for the forest and a considerable amount of time was spent in searching known locations but to no avail. Not Autumn flowering but the other orchid found was Dipodium roseum which was heavy with capsule. Some of the stems had up to eight large pods hanging on them.
At Mt. Lyon Native Forest Reserve we were able to view many Cryptostylis subulata in flower and capsule. Another trip was made to Honans to locate C. subulata from provided GPS readings. After a bit of interesting navigation both swamps were located. However we were unable to find the target species, one swamp appearing to now be too dry to sustain this species.
A quick trip was made to Telford Scrub Conservation Park following one of the survey days. Here we saw Eriochilus sp. in flower. This time they were large flowers with tall, almost robust stems. Leaves were yet to emerge. Another surprise was to await us here. Bunochilus spikes were well up and it was evident there were two species represented. Some of the spikes were quite pinkish with leaves still tightly furled on the spike. Flowering will clarify more for us; some of the spikes will have a long growing time.
Upon completion of the surveys some members headed for Piccaninnie Ponds Conservation Park in yet another attempt to locate Eriochilus in flower. This time we were successful. It is a long way to travel when not knowing the exact flowering time for the area, and those times can change with each season! On short thin stems, small flowers with still the same general appearance were what greeted us. There were buds and capsules present as well, but most interesting to us was the presence of obviously earlier capsules. One had already dehisced and all were far more robust and distinctly different from the smaller red-striped hairy capsules of the currently flowering species.
On next to more Native Forest Reserves. Once again the target species was Eriochilus but we were hoping to find among the flowers some colourful pink specimens. It seemed this time we were a little too early because few flowers were seen. However, a strong coloured pink flower was located and so became much photographed. The next area was low open forest with bracken and heath understorey. Showers caught up with us and lowered the visibility very considerably. This made it hard to look for small greenhood type flowers but possible to find, once again Eriochilus sp. Some lovely double headed flowers were seen but no leaves were evident.
At this early stage of the year it was amazing how many orchids were seen, albeit over quite a wide ranging area. Perhaps some worthwhile early rains in the lower SE had been useful, but most of the species are not heavily dependent upon this for their Autumn appearance.
NOSSA 