Journal Number 113
August 2009

AUSTRALIAN NOTES
By David McConachie

Bracalba Section of the D'Aguilar Range Walk, April 2009

Abridged from David Jones The Kalhari pp.12-14 ANOS (QLD) Kagi Group May 2009

A group of five Kabi members met near the intersection of the D'Aguilar Highway and Raaen Road at 9 on the morning of Sunday 26 April 2009 as part of Kabi's monthly bush walk program. Raaen Road meets the D'Aguilar Highway just past the top of the Bracalba section of the D'Aguilar Range.

The area walked was part of the Beerburrum West State Forest. The walked area was within the ridges and gullies on the southern side of the D'Aguilar Range adjacent to the Bracalba Quarry.

The sub-surface materials in the area were residual soils derived from granite or granitic rocks. This resulted in sections of the tracks being very "slippery" due to the surface covering of loose granite gravel (grains within the granite are left were the rock weathers).

The soils were also very dispersive resulting in deep erosion gullies along the sloping sections of the tracks. And I mean deep. The deepest were three to four feet deep and two feet wide at the surface. Dispersion means that contact with water causes the soil to go into suspension in the water.

No orchids were found along the ridge tops. The first orchids were not seen until we were a substantial way down the range slope. These orchids were in the bottom of a narrow gully on the southern side of a main ridge. The gully ran from west to east. These orchids were all terrestrials growing on the steep sides of the gully and track side cuttings. Leaves of Chiloglottis, Acianthus and Corybas were the first found. Inflorescence's and buds were starting to arise from the Acianthus and Corybas.

A couple of the Chiloglottis were in flower but this didn't help very much with identification.

The group then proceeded up the gully and was rewarded with many more leaves of Chiloglottis, Acianthus and Corybas. Again some of the Chiloglottis were in flower. Also inflorescence's and buds were starting to arise from the Acianthus and Corybas.

The lower section of the western side of this gully rewarded the group with a large colony of Pterostylis baptistii. Seven plants were in flower and two flowers were already spent.

Mid way up the eastern side of the gully the first couple of flowers on some of the Acianthus inflorescence's were open. These flowers identified the plants as Acianthus fornicatus.

The group then proceeded back up the main ridge and investigated the gullies to the north.
These gullies had a wide bottom which was overgrown with Lantana. The only orchid sightings
in these gullies were a lone Cymbidium sauve in a hollow side limb of a eucalyptus stump and
a Dendrobium aemulum on an Iron Bark. Both these orchids were on the eastern side of the gully.

The group then returned to the top of the main ridge and proceeded down a track heading towards the north-east. This track quickly joined the disused Caboolture to Kilcoy rail line formation (right-of-way). The stone-pitched abutments of a road bridge crossing still able to be seen.

A number of plants of Dipodium variegatum were seen along the northern side of the railway formation cuttings. These plants had up to three old inflorescence's. One plant had eight to ten green seed capsules. These still showed the spotted pedicle and withered spotted flowers which allowed them to be identified as D. variegatum. These capsules were probably only a couple of months old.

The walk concluded with lunch (BYO) in the park along the main street of Woodford township.