Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Monday, May 14, 2012

Lower Shoalhaven record for Olearia ramosissima.

Two weeks ago I was with Alan Stephenson, looking for Orchids in the Lower Kangaroo Valley area (Three Views Track). I noticed a small, twiggy sub-shrub (about 30 cm high), with small blue daisy-like flowers.

Separate florets within the Olearia ramosissima "capitulum".
My first impression was it was a "daisy", but it appeared to lack the usual arrangement of "ray florets" (which it does have, clearly) and the normal cluster of minute fertile "disc florets" as we are all familiar with in classic and common "Daisy flowers". This plant has about 8 moderately large "florets" in the centre. In Botanical terminology the entire floral structure of Asteraceae plants is called a "capitulum" ***. My friend Kirsten had previously suggested Brunonia as a possible ID. That made good sense, to me, as the classic flower structure of that genus looks right - especially the individual flowers (disc florets) shown at the bottom of the illustration.

Brunonia australis - Ferdinand Bauer Illustration (ANBG)
But I kept saying but mine does not have the minute "disc florets" of a classic Daisy. Kirsten's reply was (as usual) :"Its not that simple. Some do, some don't". She's normally correct with these Oracular proclamations. And so it has come to pass, in this case.
The "flower" is close to the Bauer illustration, but not the plant structure.

Classic daisy flower illustration of Ray and Disc Florets
 The stems were very rough, almost warty. Hardly any proper leaves at all. It was what I have described as a twiggy sub-shrub with warty protrusions.
I took a couple of photos, but they were not really clear enough to allow a proper ID. So a week later I went back again, in search of this little plant, and managed to find it again (fortunately).

My Facebook colleague Robyn who works at the Atlas of Living Australia agreed to help, by contacting the relevant experts at the Australian National Herbarium. it is great to have contacts in the right places.

Today I received the following message from Anna of the Australian National Herbarium (Canberra).
In fact, the distribution of this species is even more weird than Anna suggested, as it has a split distribution between Western Australia (Esperance region) and northern NSW, but with a couple of outlying records, including one, crucially from Shoalhaven Gorge. That links the known range of his plant directly with the location where I found it.
Incidentally, the West Australian "Florabase" records show a "common name" of "Much-branched Daisy Bush". That fits with my impression of a "twiggy sub-shrub with daisy-like flowers"
The distribution map for this species reminds me of several other Australian organisms which have disjunct distributions -  a factor which was always explained in terms of the prehistorical drying of the Australian continent resulting in similar members of a family of animals becoming separated because of the extension of the arid zone in the middle of their original range.

In birding circles, the classic cases are the Western Spinebill and the Western Bristlebird. But there are many other examples, such as the various species of Black-Cockatoos in Western Australia, which have speciated away from their cousins in the east of Australia (or is it the other way around?) An old example of speciation being caused by long-standing Climate Change.

Anyway, back to the specific features of this plant,
as described by the various authorities.

My second photo of the "capitulum" of the Olearia ramosissima 
And now to the most troubling feature, for me:  the strange "leaves":
  • PlantNET says: "Leaves alternate, densely crowded; lamina elliptic or obovate or triangular, 0.5–5 mm long, 0.3–2 mm wide; apex acute or rounded, without a mucro; margins entire, strongly revolute; surfaces discolorous, upper surface minutely tuberculate, lower surface grey-woolly; venation indistinct; sessile or subsessile".
  • You may check any terms which trouble you on the PlantNET glossary.
The bit it does not appear to say is that the leaves appear to be growing in tiny "rosettes" from nodes along the stem - some pointing upwards (along the stem) others pointing sideways, and some facing backwards. (That is definite "Layman's speak" for what I see in front of me.). But it does refer to the "warty surface" I had noted ("tuberculate").

Click to enlarge this image.
Leaves of Olearia ramosissima
Compare the "leaves" with
this image by Murray Fagg, at the ANBG
 This second image is just to show more of the stem, to put the previous in age in context.
Leaves and dead flower of Olearia ramosissima
In retrospect, the dead flowers (seemingly without setting seed) is one of the main problems I had in identifying this as definitely one of the Daisy tribe (Asteraceae). Murray Fagg's image from the ANBG image collection clearly shows the classic seed structure of a Daisy ("Achenes")
"Achenes silky; pappus with 27–47 long bristles in 2 series, with an outer row of short bristles."(Source: PlantNET) See Botanical illustration figure K.

Anyway, in conclusion, I am now totally confident that the ID which was suggested to me by the Australian National Herbarium's, Brendan Lepschi, is correct. The flowers match, the leaves match, and the distribution (the location where I found my plant) fits with previous records for this species. My only regret is that the regular sources for native plants of the Sydney region fail to report the existence of this plant. A reminder that even the best "text books" are at best - generalisations.

And that is why I shall go ahead to register this "record" with the Australian National Herbarium in Canberra and the Atlas of Living Australia and I will make sure that the local officers of the National Parks and Wildlife Service (who I know quite well) are aware of this species being found in the Morton National Park, at Three Views Track (above Tallowa Dam). it is but one of many interesting species found along that Track.

*** capitulum (head): a dense cluster of more or less sessile flowers, e.g. in Asteraceae a group of florets sessile on a common receptacle

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