Large trees are not common in the vine-scrubs of Pine Mountain. The rocky soils and hot, dry climate mean that—apart from scattered emergent figs, hoop pines and Flindersia—the canopy tends to be only between five and ten metres tall. However, in certain microclimates (sheltered southern slopes or creek banks), a more developed type of rainforest grows.

In my various excursions to the Kholo Enviroplan (Cameron’s Scrub) Reserve, I had long noticed from a distance some tall, dense rainforest growing in a remote valley wedged between the council reserve and the Corbould Land Trust’s Sapling Pocket Nature Refuge. After years of procrastination, this was the destination during my recent visit to Cameron’s Scrub, as part of a monthly access permit I have through Ipswich City Council.

This blog post is all about some of the interesting plants I found in this valley. Unfortunately, most of these weren’t in flower or fruit, so I warn readers now to be prepared for a lot of leaf pictures! Those easily offended or bored by images of plants are advised to hit the “back” button now.

In fairness, there were actually a handful of species flowering or fruiting as I walked the main tracks of Kholo Enviroplan (Cameron’s Scrub) Reserve.

It wasn’t long after I started the descent into the valley that I realised why I had put this journey off for so long. The slopes are very steep, rocky and covered with a dense cover of Green Panic (Megathyrsus maximus) and Coral Berry (Rivina humilis). These weeds perfectly conceal the uneven ground. It didn’t help that I chose a day with scattered showers, so my pants and shoes were saturated within minutes and stayed wet all day.

Weeds aside, I hadn’t ventured too far down the northwest-facing slope when I started to find some plant species I have only encountered in one or two other places in Pine Mountain.

Once I arrived at the ephemeral creek at the base of the hill and began my ascent up the south-facing slope on the other side, the forest immediately changed. Suddenly I was surrounded by trees of a size I’m not accustomed to seeing in the vine-scrubs of Pine Mountain. Most of the tallest were Flindersia xanthoxyla or Vitex lignum-vitae, but there were many other species here that I had never before seen so large.

Many of the species I found on the southern slopes of Flinton’s Hill back in March were also here in abundance, including Sarcomelicope simplicifolia, Argyrodendron trifoliolatum and Alangium villosum, but a major difference was the abundance of Hernandia bivalvis on the southwest-facing slope of this valley. This near threatened tree was easily one of the most abundant species present. While not especially impressive visually, I thought this next photo was interesting, as it showcases three of the iconic trees of Pine Mountain growing side by side: Hernandia bivalvis, a near threatened species with one of its most important populations here; Cryptocarya sp. Worlds End Pocket, a species named after our location; and of course Araucaria cunninghamii, the pine after which the suburb is named.

There were three trees and shrubs I found in this valley that I had not previously recorded elsewhere in Pine Mountain. The first was the midstorey shrub Bouchardatia neurococca. I was aware that this species was known from the reserve, so I had been expecting to find it at some point. This ended up being relatively common close to the creek through the valley.

The second species (Claoxylon australe) has also been previously recorded by others in the local area, but is obviously restricted to very sheltered locations. I only saw it at the base of the valley, in the same general area as the Bouchardatia.

The final species was particularly exciting to me. Monococcus echinophorus is a 1-2 m high shrub that grows in the forest understorey. It has become increasingly uncommon due to competition with weeds. I had been told about a small population that grows on Pine Mountain itself, but know of none within the reserves. I have planted some at home (growing very well) sourced from the foothills of the Toowoomba Range. So I was very excited to be able to collect some cuttings of local stock. The species grows very easily from cuttings, and is one of few drought-tolerant shrubs that can tolerate relatively heavily shade. It provides great cover for whipbirds, shrubwrens and buttonquail. I only found a single colony of half a dozen plants and they were growing in a sea of Coral Berry, Rivina humilis. I suspect it is a matter of time before the weeds push this population to extinction. This motivates me even more to establish a population of local stock on our property, where the weeds can be kept at bay.

While it was refreshing to discover that Cat’s Claw Creeper has not yet found its way into this valley, the same cannot be said about Coral Berry, Rivina humilis. This weed carpeted most of the forest floor.

Occasionally there were small patches of ground without Coral Berry, and it was interesting to see what was and was not present. Native species that rapidly colonise my restored areas at home, such as Cyperus gracilis, Commelina diffusa and Einadia spp., were strangely absent. Instead, the most abundant groundcovers were Pseuderanthemum tenellum and two native species of Aneilema. These are all species I had not even encountered anywhere else at Pine Mountain, so it was odd to see them so abundant.

Pseuderanthemum tenellum far outnumbered the usually more abundant P. variabile, even though the latter was also present in low densities. One even supported the larva of a Leafwing butterfly, which for some reason don’t feed on the taller P. tenellum.

The following groundcover species were only observed occasionally, where the Coral Berry was least dense.

Being in such a remote area, it was refreshing to see many orchids and other species that are often poached by gardeners. I was particularly interested to see what species of trees were most often used by these epiphytes as host plants. I was very surprised to see that, despite the abundance of fibrous-barked Vitex lignum-vitae and others, the most common host of many epiphytes was actually the smooth-barked Capparis arborea. I suspect the reason this species is so popular among epiphytes is that it is so slow-growing, which means that by the time a sizeable trunk has formed, it is typically covered by lichens and mosses that have had decades to develop. These in turn provide a favourable substrate for the tiny spores and seeds of ferns and orchids to germinate.

The orchids were more variable in their host choice. I saw numerous pencil orchids (probably Dockrillia bownmanii but it’s hard to be sure without any flowers), growing on Alectryon tomentosus and Siphonodon australis. While another species (what I took to be Sarcochilus parviflorus, but again uncertain without flowers) was growing precariously on the spindly stems of Parsonsia paulforsteri.

Given the sheltered location, I expected to encounter some Staghorn or Elkhorn Ferns (Platycerium spp.). However, one Elkhorn was all I found, and even this one had mostly died during the drought. Pine Mountain is a very dry location, afterall, so these inhabitants of wetter rainforests really struggle here.

One of the biggest surprises of the day was in fact not a plant at all, but a bird. Given the amount of time I have spent exploring Cameron’s Scrub in the past, I really wasn’t expecting to find any new bird species for the area. However, the tall dense rainforest within the valley harboured a pair of Brown Gerygones, an abundant bird of the wet, high-altitude rainforests of the nearby D’Aguilar Range, but one that is absent (usually) from vine-scrubs. Unfortunately, given the wet weather and treacherous terrain, I hadn’t brought along a long lens suited to photographing tiny birds in the canopy. I was impressed I managed the ones I got with a macro lens!

It truly is impressive how geographic aspect plays such a large part in the composition of our local vine-scrubs, with numerous rainforest species only able to cling on within the sheltered valleys and southern slopes. In the six hours I spent exploring one valley last weekend, I felt like I barely scratched the surface. I’m certain there are all sorts of interesting finds still to be made. Just remember, if you are interested in exploring the botany of Cameron’s Scrub, be sure to contact Ipswich City Council for a permit beforehand.