Olearia arckaringensis, flower. Photo: A.C. Robinson.
The plant was first discovered in 2000 in gullies of breakaways in an isolated pocket of Arckaringa Station by DEWNR scientists Rob Brandle and Peter Lang. The daisy was recognised to be a new species and described in 2008 by Peter in the Journal of the Adelaide Botanic Gardens (895kb PDF). A further two populations were found in 2011 along the same breakaway system on the neighbouring property, Evelyn Downs. In 2016, O. arckaringensis was listed as Endangered under the federal EPBC Act (80kb PDF).
The recent survey discovered several new population of the species. The search took more than 100 hours and covered more than 100 km of breakaway country. The survey team counted and mapped well over 2000 Arckaringa daisy plants and confirmed that the species is rare with quite specific habitat requirements. It was mainly restricted to breakaway sites that had a softer more powdery underlying substrate and were situated in less exposed areas.
Voucher specimens of Olearia arckaringensis and other plants were collected for the State Herbarium and the Seed Conservation Centre. Such collections are vital to build plant knowledge and improve scientists’ ability to accurately describe and identify different species, whilst the stored seeds are a valuable insure against species extinction.
Olearia arckaringensis, old shrub with woody base. Photo: R. Brandle.
The plant is a small, compact perennial shrub, usually to around 30 cm tall, with grey-green leaves and light violet-lavender flowers (occasionally white) borne on long stalks. It rapidly develops a thick woody base from which it can regrow.
Sometimes, working with algae can be frustrating. Collections come in to the State Herbarium of South Australia from various sources – SA Water, Natural Resource Management groups and Marine Biosecurity, for example. Collecting algae for identification can be a bit of a lottery, however. If essential reproductive stages are missing, and these often can’t be seen by the unaided eye, algal workers at the Herbarium can only provisionally suggest names which is disappointing for both collectors and those attempting the identification. But then, if we are lucky, we can also get samples that are bountifully fruitful, literally smothered in remarkable, although often microscopic, reproductive organs.
Whole plant (left) of Heterosiphonia muelleri and magnified detail (right) of the fluffy appearance. Photo: Bob Baldock.
One such case came from 5 m deep at Cable Hut Bay, near Cape Spencer, southern Yorke Peninsula, collected by James Brook. The alga was dotted with products of sexual reproduction (cystocarps) looking like the fruits of terrestrial plants.
The alga was Heterosiphonia muelleri (Sonder) De Toni in the Dasyaceae, a family named from “dasya” (Greek) meaning “shaggy”, an appropriate description looking in detail at the fluffy branches of this species (see also the Algae Revealed key to common red algae of South Australia, part V, 2.3mb PDF).
Two magnifications of cystocarps, one on a denuded part of the plant, the other with cystocarps nestled amongst threads. Photo: Bob Baldock.
More remarkable than the mass of thin threads covering the plant were the bright orange to red-brown cystocarps. These were stalked, semi-transparent “flasks”, with elegant conical necks through which the spores (carpospores), clustered within, are released to germinate into the next stage of the algal life cycle, an asexual spore plant. Under the microscope they looked “good enough to eat”, but, unfortunately, would not have proved a sumptuous meal, even though numerous.
With such beautifully reproductive material, identification was practically ensured. A look through the microscope showed ranks of large cell alternating with small ones along main branches, characteristic of the family Dasyaceae.
All that remained was to section and stain blue one of the main branches (axes). A central large cell with a ring of 10 small ones, wrapped (corticated) with even smaller ones was present and clinched the identification.
Surface view of a main branch (left) and cross section (right) of the axis of Heterosiphonia muelleri, stained blue and viewed microscopically. Photo: Bob Baldock.
It’s always a pleasure to work with such material, and satisfying when we can be sure of an identification, and I hope this gives you insight into some of the tasks involved in working with algae at the Herbarium.
Contributed by State Herbarium Hon. Associate Bob Baldock.
Scutellinia scutellata, Flinders Chase National Park. Scale bar = 10 mm. Photo: David Catcheside.
A small orange disc fungus, Scutellinia scutellata, is the State Herbarium of South Australia‘s Fungus of the Month for October 2017. This little fungus is widespread, but particularly spectacular in DEWNR’s Park of the Month, Flinders Chase National Park. The common name for Scutellinia scutellata is “eyelash fungus”, because of the long dark hairs fringing the margin of the brilliant orange disc.
Scutellinia scutellata, Flinders Chase National Park, fresh herbarium collection PSC4233. Each division of scale bar = 1 mm. Photo: David Catcheside.
Scutellinia scutellata (L.) Lambotte is a common disc fungus with a worldwide distribution. It is saprotrophic, growing on rotten, wet wood, sometimes on soil but in association with wood. The fruit bodies may be in clusters or gregarious over the wood.
The generic name is derived from the Latin scutum, a shield, with the suffixes -ella, denoting the diminutive stature, and –ineus, meaning resembling. The specific epithet scutellatum means shield or saucer shaped.
The fruit bodies, apothecia, are small, stemless saucers of height 1–5 mm and diameter 2–10 mm, although they may reach a diameter of 20 mm. The apothecia start as tiny spherical knobs which expand and become saucer-shaped. Later the saucers flatten into discs with upturned margins. The surface of the upper disc is bright orange to orange red, its margin is fringed with stiff, bristle-like black-brown hairs to 1.5 mm long. The lower surface is brownish due to the dense brown hairs.
Scutellinia scutellata, hairs on outer surface of apothecium. Scale bar = 10 µm. Photo: Pam Catcheside.
Anthocercis angustifolia in the understorey of a Sheoak woodland in Morialta Conservation Park. Photo: P.J. Lang.
Rays of delight on a rocky path
Anthocercis angustifolia, close-up of flowers. Photo: P.J. Lang.
Our new plant of the month is the rare endemic South Australian shrub, Anthocercis angustifolia F.Muell. (Narrow-leaf Ray-flower). It has a patchy disjunct distribution restricted to a few pockets in the Mt Lofty and Flinders Ranges where it is associated with rocky slopes, escarpments and gorges. One of the best places to see this unusual plant is in DEWNR‘s Park of the Month for August, Morialta Conservation Park. It is currently in flower on the upper walking trail just above Kookaburra Rock lookout and southwards towards the waterfalls. Anthocercis angustifolia is a fire responsive species and it came up in profusion here after this area was burnt several years ago. The illustration above shows it in a successional phase dominating the understorey of an Allocasuarina verticillata Sheoak woodland. The delicate white to creamy-yellow flowers have long narrow corolla lobes from which the genus takes its name based on the Greek anthos, a flower, and kerkis, a ray. When not in flower A. angustifolia may be recognised by its sparse erect habit and slender leaves with small glandular hairs making them clammy to touch. Anthocercis species are known to be poisonous and contain tropane alkaloids.
Anthocercis angustifolia near Gorge Road. Photo: SA Seed Conservation Centre.
Anthocercis is a well-defined apparently monophyletic genus comprising c. 11 currently recognised species. Its centre of diversity is in Western Australia, with most species confined to that State. South Australia also has a second species, Anthocercis anisantha, which extends from WA and has a more compact and spinescent habit. Comprehensive fact sheets on this and other Anthocercis species are available under ‘Identification Tools’ on the efloraSA website, together with an interactive Lucid key to Australian Solanaceae. These useful but often overlooked resources were put together by State Herbarium Honorary Associate Robyn Barker. An illustrated Plant Portrait was published in the Journal of the Adelaide Botanic Gardens 7(3) 309-311 (1985) (580kb PDF). Further information can also be found on the Seeds of South Australia web-site and the Atlas of Living Australia (ALA).
Anthocercis angustifolia. Photo: P.J. Lang.
Contributed by State Herbarium botanist Peter Lang.
Great fleas have little fleas upon their backs to bite 'em,
And little fleas have lesser fleas, and so ad infinitum.
And the great fleas themselves, in turn, have greater fleas to go on;
While these again have greater still, and greater still, and so on.
Augustus De Morgan, A Budget of Paradoxes(1872)
The apparently simple specimen that proved to be a whole community of marine organisms. Photo: B. Baldock.
LEFT: Remains of the slightly calcified exoskeletons of individual zooids in the bryozoan colonies. RIGHT: Part of the inter-connected chambers of the tree-like sponge, walls stained blue. Photo: B. Baldock.
At first sight I thought the specimen was simply a group of “moss animals” or bryozoans (probably Canda arachnoides Lamouroux, above left). But closer inspection proved that the bryozoans were growing on a tree-like sponge full of inter-connected chambers (above right).
In addition, under the microscope, I found four algae – a veritable community coating the sponge. Labelled with red numbers 1 to 4 in the images, below.
(1) Dictyopteris gracilis, delicate sporelings attached to a sponge skeleton (top), which is stained blue, and a single flimsy blade (bottom). (2) Lejolisea aegagropila, female structure (top) and stalked sporangia (bottom), stained blue. Photo: B. Baldock.
The largest, a Brown alga, Dictyopteris gracilis Womersley (no. 1), consisted of sporelings “babies”, getting established on a relatively stable, hard substrate, a requirement for most algae to survive. They could have grown into quite elegant, leaf-like plants some 200 mm tall. Their growing centres (meristems) are found in the notch at the apex of the delicate filmy blades. See the Algae revealed factsheet for the species (420kb PDF).
In addition, there was a tangled set of microscopic pink threads, Lejolisia aegagropila (J. Agardh) J. Agardh (no. 2), easily recognised from its female reproductive structures (procarps and cystocarps) that resemble glass light-bulbs. Mixed in with the female plants was another stage in the species life cycle – a spore plant with packets of 4 spores (tetrasporangia) on minute stalks.
(3) Acrothamnion preisii, elegant feathery (pinnate) side branches tipped with a glistening gland. (4) Audouinella spongicola, minute threads of the Red alga (arrow), running along the blue-stained walls of the sponge which shows ,also, needle-like skeletal spicules. Photo: B. Baldock.
Perhaps the most striking, however, was the Red algaAcrothamnion preissii (Sonder) Wollaston, with its elegant “feathers”, each ending in a glistening gland (no. 3).
The most unusual alga, although obscure, consisted of lines of elongate red cells (no. 4) running on the surface and around the walls of the inter-connected sponge chambers. These belonged to threads of a very simple Red alga, Audouinella spongicola (Weber van Bosse) Stegenga, which, as its name denotes, specifically lives on sponges.
The common, single-celled foraminiferan Discorbis dimidiatus, its shell punctured with minute pores, lives amongst the algae attached to the sponge. Photo: B. Baldock.
There were other microscopic organisms: shell-like unicellular animals (foraminifera), diatoms with glassy walls; and inevitably, bacteria, but I stopped investigations at the plants and animal described above, thinking I had enough evidence to support the sentiment in the adage at the start of this article.
I hope the BRUVS people can continue to send more, minute but nevertheless interesting marine communities to us at the State Herbarium. You never know what will turn up in the marine world.
Contributed by State Herbarium Hon. Associate Bob Baldock.