Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Thursday, November 18, 2010

A rare plant: Grevillea raybrownii

Several days ago I went to Medway and found myself in a sandstone gully over there. We are talking about a little township, west of Berrima. This site is close to a working coal mine, which apparently is about to be greatly expanded, with the introduction of longwall mining.

Medway includes one of my favourite places to visit - in search of Orchids and other unusual native plants. There is an old (overgrown) sports reserve - just a couple of acres, on the edge of the village. However, this patch of scrub which I normally visit has been burnt out. It was obviously a deliberate "burn-off" because the edges of the burn were very accurately controlled. Any spring Orchids are gone, but they will be back in future years, (hopefully). The autumn-flowering Orchids may be benefited by the burning. Some people maintain it is a chemical factor (the potash and smoke-water). Personally I think it is the lack of competition from shrubbery and grasses which mostly helps the Orchids. Anyway, it will be interesting to monitor the recovery.

I left the sports reserve and went to another favourite spot of mine. There is a steep gully, and I noticed a high sandstone rock shelf (across the gully) which I had never visited before. On my way across, I found just a few Donkey Orchids (Diuris sulphurea) but these are pretty common in the Southern Highlands. I did not photograph any of these Orchids.

I was hoping to find something unusual in the moss beds which I expected to find on the rocky outcrop. When I climbed up there, I saw a number of Calytrix tetragona plants (same species I had seen in Goulburn last weekend). But no Orchids, alas.

But what on earth is THAT?
As I worked my way back across the creek, I realised
I was looking at a large shrub which I had never seen before.
Prickly leaves, reddish new growth tips, and white flowers.
Within a moment I had worked out it was a Grevillea - a "Toothbrush Grevillea". That name comes from the shape of the inflorescence - the compound structure of many, many flowers.
The next thing I noticed was the compound divided shape of the leaves, and their sharp points. Technically this leaf shape is described as: "bipinnatisect with the secondary lobes often divaricate".
Finally I noticed the fat seed pods with purplish-red stripes along the basic grey-green colour of the outside of the ripe follicles.
These three characteristics immediately reminded me of the Carrington Falls Grevillea. Clearly it was a different species, but closely related. Both grow on sandstone, but this one was growing on an exposed rock shelf, whereas the other species grows close to rivers in wet forest.

So, similarities aside, what was it?

Eventually I tracked down a reference to Grevillea raybrownii in PlantNET. Two days later I found a photograph which helped me confirm the ID of this rare plant. I cannot find any photograph published on the Internet - before this. Is this really a world first? It might just be.

The only photo I have found is in the 3rd edition of Fairley and Moore "Native Plants of the Sydney Region" (which has just been published in September 2010).
It is reported that the pollinator is not known.
Well, there is a small to medium sized black ant here.

The plant was officially named (described) in the botanical journal "Telopea" Vol 5 (4) 1994 by Olde and Marriott.

This plant species is recorded here in "Flora of Australia Online".
NOTE: In case that link does not work for you (it didn't work for me, at first). But if you type in Grevillea raybrownii to this ANBG "Australian Plant Name Portal", then click "Flora of Australia online" - the second "radio button" from the bottom of the list, the desired entry should open for you. You may have to scroll the page sown to find this "Flora of Australia Online" button. But this system does work.

Habitat shot (for Mick).
Rock shelf, with Scribbly Gum and Calytrix scrub.
Gully beyond.
Looking towards far side of valley.

It is interesting to note the herbarium collection specimens examined by Olde and Marriott. The oldest is from 1901 from Berrima, close to where my plant is living. Those specimens would have been filed under Grevillea triternata, and then re-classified following Olde and Marriott's publication in 1994.

"SELECTED SPECIMENS (from 18 examined): NEW SOUTH WALES: Central Coast: Divide between the Nattai River and Allum River, Olsen 2183, 25 Jun 1974 (NSW); West Dapto, Cambage, May 1904 (NSW). Central Tablelands: Berrima, Maiden, Sep 1901 (NSW, MEL 595889); Mandemar Creek track, old road through to Joadja, Stead, 5 Apr 1975 (NSW 136247); Bullio tunnel, Mittagong-Wombeyan Caves Rd, Taylor 366, Goodwin, Bishop & Gunnell, 10 Dec 1984, (NSW, B, CBG, K, PERTH, RSA); 19.2 km NE of Robertson on No.1 fire trail in the catchment area of the Avon Dam, Coveny 848, 24 Feb 1969 (NSW)."

(DJW Note: That is one rare plant which the SCA Environmental Consultants missed in their surveys for the Kangaloon Aquifer. The area described is within the borefield area. Grevillea raybrownii is listed on the Rare or Threatened Plants list (ROTAP) for the Illawarra Region.)

Re the name: Olde and Marriott say: "ETYMOLOGY: The specific epithet honours Mr Raymond Brown (1947-), nurseryman of Bulli, New South Wales, for his contribution to the horticulture of Grevillea; he also first directed our attention to this species."

DJW notes: Ray Brown is credited with the idea to establish the famous Illawarra Grevillea Park, at Bulli (Wollongong Suburb).


mick said...

Thanks for the habitat photo. I always like these! Great to find such a beautiful and rare grevillea so unexpectedly.

Gouldiae said...

Nice job Denis,
You've put some work into that one. Congratulations on the find and also on the effort to produce a brilliant blog entry. Wonderful plant.

fnkykntr said...

Very interesting post. I sometimes stumble upon specimens in the Australian National Botanic Garden here in Canberra that are from one tiny spot somewhere in Australia, I always marvel how in such a big country a plant can be so confined to a single valley and how there is still so much to learn about the flora and fauna here.

Denis Wilson said...

Thanks Mick and Gouldiae
Yes I spent a lot of time on that post, and the research - glad you appreciated that, Gouldiae.
Mick I hope to get another wide angle shot some time. It is a pretty spot, and so unexpected, being up on a ledge there.
Dr. Hazel, welcome to my Blog comments.
I have taken the liberty of adding your "Lunchtime Adventures in the Gardens" blog to my list of Aussie Nature Bloggers. Honorary Aussie in your case, but Aussie Nature undoubtedly.
I was a Volunteer Guide at the ANBG for several years, before I moved to Robertson. Great place.
I urge other readers to check out Hazel's amazing post and videos of Bowerbird mating rituals and even the event itself.
You must be very patient, Hazel.
Back to your comment, Australia has been here for such a very long time that "speciation" is abundant. Grevilleas in particular are very localised. We have the Carrington Falls Grevillea here in Robbo which is only found in one River valley.
Millions of years of waiting can do that for you. Europe has been so churned over by glaciation that most of their plants are "new".