Category Archives: The Plant Press

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.

Plant of the Month: April 2017

The State Herbarium of South Australia‘s Plant of the Month for April 2017 is Leptospermum lanigerum, a species that also occus in DEWNR’s Park of the Month, Deep Creek Conservation Park.

Leptospermum lanigerum near the SA-Vic. border. Photo: C.C. Clarke, ALA.

Leptospermum lanigerum (Aiton) Sm. has the common names of “silky” or “woolly tea-tree”. It is found in Deep Creek Conservation Park along its permanent creeks, around its waterfalls and in its swamps. There it is often associated with other wetland species such as Eucalyptus ovata, Leucopogon lanceolatus, Correa eburnea, Goodenia ovata and Blechnum ferns.

L. lanigerum, seeds. Photo: SA Seedbank.

The plant’s scientific name is derived the Greek words “leptos” and “sperma” meaning “slender seed”, which directly relates to the seeds of the type species L. scoparium, but also applies to L. lanigerum; “lanigerum” is from Latin for wool–bearing, describing the hairy fruit, buds and leaves of the species. The genus is commonly called “tea-trees”, a name which originated from the crews of Captain Cooks voyages who brewed tea from the leaves in an attempt to prevent scurvy.

L. lanigerum, flower, Photo: R.Wiltshire, Wikimedia (CC-BY-SA).

The silky tea-tree occurs from the Mt Lofty ranges east to Victoria, New South Wales and Tasmania. The Type was from material cultivated in Kew Gardens from Cook’s second voyage in 1773 after seed was collected by Captain Furneaux of the HMS Adventure in Tasmania, so becoming the first Leptospermum brought into cultivation.

In South Australia, it grows into a small tree but can become quite large in springs on Western Kangaroo Island. Its white flowers are prominent in late spring and attract many insect pollinators such as jewel beetles. The seeds are held in woody capsules and are released after fire or other disturbances, but the species also possess lignotubers and epicormic buds and can grow back quickly after fire.

As its common name describes, the silky tea-tree’s hairy leaves gives the plant an attractive grey-silver sheen, it commonly grows with the greener foliaged “prickly tea-tree” Leptospermum continentale, and hybrids with intermediate characters are fairly common. A green variant of L. lanigerum also occurs in the South-east of South Australia and Western Victoria and was considered by Joy Thompson in a revision of the genus (Telopea 3(3): 301-449, 1986, 17.7mb PDF) to be a possible relict influence of L. nitidum that now occurs in Tasmania.

L. lanigerum, fruit. Photo: Lyn Allison, ALA.

The recent high prices for New Zealand’s Manuka honey from L. scoparium has created much ongoing interest and research into Australian Leptospermum species. Many Australian species have been found to have significant levels of DHA (dihydroxyacetone), with one website report noting that L. lanigerum “ticks many boxes”. Selection of high yielding populations and breeding programmes are continuing (see ABC report).

Note that the related species Leptospermum laevigatum (coastal tea-tree) from Victoria, Tasmania and New South Wales, is a highly invasive weed in most Australian states and now declared in South Australia (580kb PDF fact sheet from Biosecurity SA).

Contributed by Martin O’Leary.

Plant of the Month: Feb 2017

Native Pig-Face, Carpobrotus rossii

Park of the Month in Feb. 2017 was Hallett Cove Conservation Park

Carpobrotus rossii

Herbarium sheet – before the plant is dried, of Carpobrotus rossii. Photo: State Herbarium.

Among the amazing geological features of an ancient landscape a plant which might go unnoticed except when flowering is the native coastal species of Pig-Face, Carpobrotus rossii. In fact, Carpobrotus (Pig-Face) is a world-wide genus of succulent plants, with species native to South Africa, Australia, South America and California.

In South Australia there are four species of Carpobrotus and two species in a closely related genus Sarcozona. Carpobrotus modestus and C. rossii are native to South Australia as are the two Sarcozona, S. bicarinata and S. praecox.

In the coastal areas of Hallett Cove the native species, Carpobrotus rossii is an important member of the ecosystem forming dune protecting ground cover and fruits that animals eat.

Carpobrotus edulis backcross

Carpobrotus edulis flower type, this plant likely to be a hybrid backcross to C. edulis. Photo: C. Brodie.

However, South Australia also has a species of Carpobrotus that is an introduction from South Africa, Carpobrotus edulis, which is listed in the Global Invasive Species Database for 24 countries.

Honorary Research Associate Dr Hellmut Toelken from the State Herbarium of South Australia has been researching the taxonomy of this group and discovered that some pairs of species may form hybrids in South Australian locations. A partnership between the State Herbarium, The University of Adelaide and The Samphire Coast Icon project and Adelaide and Mount Lofty NRM applied molecular techniques to work out what was going on. The DNA analysis that this project conducted revealed that Dr Toelken was correct, and in fact there are many hybrids forming between the local native species and the introduced one. Hybrids are widespread in many areas, in fact where the two species come into close proximity.

A big problem is that while the yellow flowered C. edulis is relatively easy to identify, the hybrids in South Australia appear to be typically pink flowered plants.

Hallett Cove Conservation Park is well known for its geological and archaeological features, and is just outside of Adelaide.

From the parks webpage:

‘In the park ‘glacial pavements’ show evidence of a large glacier that covered the park and surrounding areas 280 million years ago when Australia was part of Gondwana. Over the past 600 million years the Park has undergone a number of changes from being beneath the sea and covered in an ice sheet to being a mountain range. Throughout the Park there is informative signage along the trail that help you understand the story of Hallett Cove Conservation Park.’

F1 C. rossii X C. edulis South Australia. Photo: C. Brodie.

More information is available on the Carpobrotus hybrid project:  Waycott, M. (2016). Hybridisation in native pigface, Carpobrotus rossii. (State Herbarium of South Australia, Adelaide). 8 pp. ISBN 978-1-922027-47-4