Category Archives: The Plant Press

Things are never as simple as they appear…

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.

This small algae specimen was collected from 21 m deep waters, at St Francis Island, Nuyts Archipelago, South Australia (see also South Australia’s offshore islands, p. 150; 33mb PDF). It was torn from its substrate by the frame of an underwater Baited Remote Underwater Video Station (BRUVS) used to film fish populations as part of the survey of Marine Parks, and was given to the Phycology Unit of the State Herbarium of South Australia in 2015.

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 alga Acrothamnion 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.

Plant of the Month: Aug. 2017

Callitris rhomboidea, branch with immature cones. Photo: T. Robinson.

Plant the Month for August is Callitris rhomboidea R.Br. (Oyster Bay pine), which occurs in DEWNR‘s Park of the Month, Onkaparinga River National Park. It is a conifer from the large and cosmopolitan Cypress family (Cupressaceae), which includes many important timber (e.g. Sequoia sp., the Redwoods of North America) and horticultural species (e.g. Cryptomeria, from Japan). Callitris includes approximately 16 species, 13 of which are restricted to Australia. The majority of these occur in heath and woodlands, extending into semi-arid areas. Recent molecular research suggests that Callitris evolved from rainforest ancestors in response to a drying climate over the past 30 million years (Larter et al. 2017) and in contrast to other Australian conifers, they are remarkably drought tolerant, allowing them to thrive in arid conditions.

Callitris rhomboidea, fruiting cone. Photo: T. Robinson.

This species is commonly referred to as the Oyster Bay pine, in reference to its occurrence on the Georges River, in the vicinity of Sydney (also known as Port Jackson pine). Callitris rhomboidea extends from coastal southern Queensland through New South Wales, Victoria and Tasmania. In South Australia, it occurs chiefly on Kangaroo Island and a few scattered localities in the Mount Lofty Ranges, including the Onkaparinga River Gorge, and the Mount Crawford region to the north. While it is widely distributed, Oyster Bay pine is only locally common, occurring on sand dunes and in rocky areas in heath and woodlands. Callitris are intolerant of fire and preferentially grow in areas that are protected by topography or slow rates of fuel accumulation. However, the Oyster Bay pine can readily regenerate from seed, which are held in the thick woody cones that cluster on fruiting branches. Like many plant species of Australia’s fire prone woodlands (for example, Banksia), fire may act as a stimulus for seed release followed by mass germination and generation of dense, even-aged stands.

Callitris rhomboidea in Hale Conservation Park. Photo: T. Robinson.

There are two species of Callitris occurring within the Onkaparinga River National Park. Callitris rhomboidea is perhaps best distinguished from Callitris gracilis (Slender Cypress-pine) by the shape of the cone scales on the female cone, which are rhomboidal (hence the name, rhomboidea) and have a distinct point near the apex.

Callitris rhomboidea is ‘Rare’ within South Australia, and has declined in parts of its range as a consequence of land clearing, grazing and weed competition. While the level of decline is insufficient to warrant listing as ‘Threatened’, factors such as high frequency fires and susceptibility to ‘die-back‘ (caused by the fungal pathogen, Phytophthora cinnamomi) are potential future concerns (IUCN Red List 2017).

Contributed by State Herbarium molecular botanist Ed Biffin.

Plant of the Month: July 2017 – Hoods in the park

Pterostylis cucullata. Photo: P.J. Lang.

Plant of the month for July is Pterostylis cucullata R.Br. (leafy greenhood), a rare and striking native orchid listed as Endangered in South Australia. And DEWNR’s park of the month, Belair National Park is critical for its survival, containing 99% of its South Australian population. Outside this park there are only several small occurrences, and the species has been lost from much of its former range in the wetter parts of the Adelaide Hills and Fleurieu Peninsula due to urban and agricultural development. All the extant populations are subsp. sylvicola, and subsp. cucullata, which once occurred near Fairview Park and McLaren Vale, is now presumed to be extinct in the Mt Lofty Ranges.

The population in Belair National Park has been monitored and managed for many years by the Friends of Parks Threatened Plant Action Group and members of the Native Orchid Society of South Australia, who have been active in controlling weeds. The orchid is susceptible to browsing, and increased numbers of kangaroos and rabbits (the latter probably in response to fox-baiting) are a more recent concern.

Greenhoods (Pterostylis) are so-named because of their hood-like galea, formed by the fusion of the dorsal sepal and lateral petals. Pterostylis cucullata is one of the larger species of this group and has distinctive velvety brown colouration on the sides of the hood. The flowers are usually borne singly and arise from the leafy basal rosettes on stalks up to 25 cm tall. They appear from late July to October and are pollinated by small male fungus gnats of the family Mycetophilidae.

Pterostylis cucullata is also found in Victoria and Tasmania. It is listed as Nationally Vulnerable and is the subject of a National Recovery Plan (140kb PDF) under the Commonwealth Environment Protection and Biodiversity Conservation Act 1999. More information is also available from the Species Profile and Threats Database (SPRAT profile), a DEWNR Threatened Flora fact-sheet (280kb PDF) and the Recovery Plan for twelve threatened orchids in the Lofty Block Region of South Australia 2010, by Quarmby (2010, p. 114, 2.1mb PDF) .

Contributed by State Herbarium botanist Peter Lang.

Plant of the Month: June 2017

Bryobartramia novae-valesiae and other strange beasts!

In August 2016, an arguably slightly eccentric group of people gathered in South Australia for the 13th Australian Bryophyte Workshop. These are regular gatherings of a small and scattered group of people from Australia (and sometimes beyond) who are interested in bryophytes: the mosses, liverworts and hornworts. Whilst a lot of people would associate these small plants with wetter areas, many bryophytes can also be found in more arid areas. This time the Workshop was organised by State Herbarium botanist Graham Bell, and was based at Pichi Richi Park in the Flinders Ranges. One of the main field sites was in Mount Remarkable National Park, this month’s Park of the Month.

Bryophyte workshop participants during fieldwork. Photo: G. Bell.

An occupational hazard of working with dry area bryophytes is the amount of time spent on hands and knees…

Habitat of Bryobartramia. Photo: D.E.A. Catcheside.

Fortunately the season had been exceptionally good, resulting in fine populations of bryophytes being observed. Some of these plants are ephemeral, only appearing in wet seasons and then surviving by means of the spores they produce. Bryobartramia novae-valesiae (G.Roth) I.G.Stone & G.A.M.Scott (no common names here, I’m afraid!) is one of these tiny ephemeral plants, and has rarely been collected in South Australia (Flora of Australia description, 134kb PDF). In fact, only one specimen from SA was previously identified in the State Herbarium collection, and only three others are to be found in other herbaria. This doesn’t necessarily mean that the plant is that rare — just that no-one with the right “eyes” has gone looking in the right places at the right time!

Graham Bell found the Bryobartramia on bare patches of clay soil near Alligator Gorge, together with a number of other tiny bryophytes.

Bryobartramia movae-valesiae, line drawing from D.G. Catcheside, Mosses of South Australia (1980).

Only two species of Bryobartramia are currently recognised in the world. They occur in Australia and southern Africa. Bryobartramia is easily distinguished from other mosses as the spore-producing capsule is completely covered by a balloon-like enlarged calyptra – this is normally lost early in the development of the spore capsule.

For something just a little larger, a wonderful population of the tiny fern Ophioglossum lusitanicum L. was also observed during a reconnaissance trip before the Workshop. This plant is not often seen, as it is an annual fern, which only reaches about 2–3 cm in height, each plant usually producing just one semi-succulent leaf. Like Bryobartramia, it lives only long enough to produce spores, which are able to produce new plants in the next wet season. Ophioglossum, like other ancient and primitive ferns and bryophytes, is also found in many other parts of the world.

Ophioglossum lusitanicum at The Battery, Mt Remarkable Natl. Park. Photo: D.E.A. Catcheside.

Ophioglossum lusitanicum showing young spore capsules. Photo: D.E.A. Catcheside.

Ophioglossum was found on the slopes of The Battery, on the western side of Mount Remarkable National Park.

This area has not been visited by many botanists, especially those working on fungi and bryophytes. Pam Catcheside, Honorary Research Associate and mycologist at the State Herbarium, who accompanied Graham Bell on this trip, found several unusual or little-collected fungi here.

On the summit of The Battery was found the fifth collection from South Australia (and only the sixth specimen ever known) of a new species of Smardaea, a small black disc fungus which grows on the sandy soil surface. This species is about to be published as new to science.

 

A new species of the tiny black fungus Smardaea. Photo: D.E.A. Catcheside.

 

Fungus of the month

The State Herbarium of South Australia‘s Fungus of the Month for May 2017 is Chlorociboria aeruginascens, a species of small disc fungi that is widespread but particularly spectacular in DEWNR’s Park of the Month, Flinders Chase National Park.

Chlorociboria aeruginascens on wood. Photo: D.E.A. Catcheside.

Chlorociboria aeruginascens (Nyl.) Kanouse ex C.S.Ramamurthi, Korf & L.R.Batra has a number of common names including ‘blue-green wood cup’, ‘green elf-cup’ and ‘blue or green stain fungus’. It is a common and widespread fungus, growing in groups on debarked wood or fallen branches, causing the wood to be stained a brilliant blue-green colour. The similarly coloured cup-like fruit bodies are found in very moist conditions in the wetter winter months.

The generic name is derived from the Greek kloros (χλωρός), meaning green, and Latin ciborium, a drinking cup. The specific epithet comes from aerugo, Latin for verdigris, a deep bluish-green encrustation formed on copper or brass, and the suffix ascens, becoming.

The fruit bodies, apothecia, are tiny, stalked cups to 5 mm high, of an intense turquoise colour. The apothecia have a diameter of 4–10 mm and initially are a shallow cup-shape but flatten to a disc with a slightly raised margin. The blue-green upper surface is smooth to wrinkled with a small dimple; the outer surface is smooth and slightly paler with a white bloom. The tiny stem tapers down and is often off-centre; it is the same colour or slightly darker than the cup and black at the base. The stem bases of the fruit bodies are attached to a black mat of hyphae embedded in the wood.

Chlorociboria aeruginascens. Photo: D.E.A. Catcheside.

Chlorociboria aeruginascens is a cosmopolitan, saprotrophic species. In the northern hemisphere it grows mostly on hardwoods, such as poplar, Populus spp., oak, Quercus spp. and ash, Fraxinus spp.; in the southern hemisphere it is on Eucalyptus spp. and Nothofagus spp., although it does grow on other woods. The wood on which it grows is usually soft, giving the appearance that it has been infected by white-rot fungi but C. aeruginascens is not considered a true wood-rot fungus. The blue-green pigment, a quinone derivative called xylindein, is secreted by the microscopic tubular threads, the hyphae, of the fungus. It has been suggested that the pigment may make the wood less enticing for termites and may also reduce competition with other wood-inhabiting fungi.

The green-stained wood was highly prized. It was used in inlaid decorative woodwork such as Tunbridge ware, marquetry, intarsia panels and parquetry. Tunbridge ware was made in Tonbridge and Tunbridge Wells in Kent, England, from the mid-18th century. Small pieces of different coloured woods, including the blue-green wood stained by Chlorociboria aeruginascens, were used to make pictures and patterns and inlaid into small boxes, fire screens and tables. Marquetry involves the glueing of small pieces of coloured wood on to thin veneers for use in furniture-making. Parquetry is a similar technique used mainly for floors. In the older process of intarsia, a solid piece of one material is cut out from a surface such as a table-top or floor and patterns made up of wood, marble, ivory and/or mother-of-pearl are inserted into the excised area (see also this article).

Collection of Chlorociboria aeruginascens (P.S. Catcheside 4378) in the lab before drying. With centimetre scale. Photo: D.E.A. Catcheside.

Chlorociboria aeruginascens is in the family Chlorociboriaceae Baral & P.R.Johnst., order Helotiales Nannf. ex Korf & Lizoň. Seventeen species of Chlorociboria are recognized worldwide, fifteen occur in New Zealand. They may be separated on the basis of spore size and shape, hyphae on the outer surface of the apothecia and on macroscopic differences such as colour of fruit body, some species having a yellow or white disc while some dry orange-brown, others blue-green. Johnston & Park (2005) have described a subspecies from New Zealand, Chlorociboria aeruginascens subsp. australis P.R. Johnst., which is morphologically indistinguishable from a subspecies found in the northern hemisphere, Chlorociboria aeruginascens subsp. aeruginascens. They may be separated only by molecular analysis, an impractical procedure in the field! No molecular work has been done on the specimens illustrated here, but it is probable that they are of Chlorociboria aeruginascens subsp. australis. Only two species from Australia are listed in the ALA, C. aeruginascens and C. aeruginosa (Oeder) Seaver. Both species look very similar, but C. aeruginosa has longer spores and larger terminal cells on the outer surface. An earlier name, Chlorosplenium aeruginascens (Nyl.) P. Karst., still occurs in a number of field guides. (See also Fungi in Australia, Part 2 and references therein; 40.2mb PDF).

Contributed by Hon. Research Associate Pam Catcheside.