Category Archives: News

New water weed detected

Myriophyllum aquaticum, plant from top. Photo: André Karwath (Wikimedia CC-BY-SA).

The highly invasive water weed Myriophyllum aquaticum (Vell.) Verdc. (Parrot feather; plant family Haloragaceae) has been found growing wild in a drainage/creek line in Nairne by State Herbarium weeds botanist Chris Brodie. The small population covering an area of 2 × 2 m was discovered growing in shallow flowing water, rooted in soft silt.

Originally from South America, the species was introduced to Australia as an ornamental for aquariums and ponds, due its attractive, luxuriant growth of blue-green stems and leaves. Parrot feather grows partially submerged, with the roots, lower stem and some leaves underwater, but the top of the plant emerging above the water surface.

Myriophyllum aquaticum, growing at Nairne. Photo: C.J. Brodie.

In cultivation M. aquaticum soon becomes dominant. The plant grows quickly and produces creeping, thickened roots (rhizomes), which produce more stems. Excessive plant material then needs to be removed and is sometimes discarded illegally on roadsides or in creeklines.

Freshly discarded plants can re-grow from a single root or stem fragments in shallow water. This aggressive growth can strongly reduce light levels and water flows, trap sediments, crowd out native vegetation and even obstruct waterways for recreational use by restricting or preventing access to the water or impeding boat passage.

Parrot feather produces male and female flowers on separate plants. So far, only female plants have been found in Australia, and therefore seeds are not produced, i.e. the plants spreads only by vegetative means. If male plants were introduced into Australia, this species could become more prolific.

It is likely that the population at Nairne is a result of dumped plant material. It is of concern because of the potential to spread. Plants are easily damaged, resulting in stem fragments breaking off and establishing in new locations downstream. With the recent and future winter rains in the Adelaide Hills, further dispersal is highly likely because of higher water levels in creeks and increased flows. The population has been reported by the State Herbarium to Biosecurity SA, who informed local NRM agencies.

Myriophyllum aquaticum has recently been suggested by Biosecurity SA to be a problem plant species (500KB PDF factsheet) and was recommended for Declaration under the Natural Resources Management Act 2004. In other States (e.g. Western Australia, Tasmania) and other countries (e.g. parts of the U.S.A., South Africa), the plant is already a declared weed. A public consultation process is currently underway and public feedback is welcomed on the South Australian Government website YourSAy.

Keeping your “eggs” in one basket

Cyanthus olla with “eggs”. Photo: Bob Baldock.

State Herbarium Hon. Research Associates Pam Catcheside and Bob Baldock report another cryptic and appealing fungus. It has appeared in the Botanic Gardens, this time amongst bark chips associated with recent plantings of pistachio saplings adjacent to the Old Tram Barn. A previous BLOG article described the coral fungus, Aseroe rubra Labill.

It is a birds nest fungus, easily passed over by the casual visitor to the gardens, but worth close inspection. Its Latin name, Cyathus olla (Batsch) Pers., literally means “cup” and “pot”. The bulk of the fungus occurs as cryptic, microscopic threads (the mycelium), infiltrating and busily dissolving the wood and bark chips for food. But the mature fruiting body is visible to the keen observer.

Cyanthus olla. Photo: Bob Baldock.

At first a ball-shaped structure forms. Then the membranous top tears to reveal a hollow interior with 8 to 10 grey-black “eggs” at the bottom of a fruiting body about 10 mm across which becomes goblet-shaped. The outside is grey-brown, covered with fine hairs at first, but it may later become smooth. Each “egg” is a spore packet a mere 3-5 mm by 1-2 mm, attached to the sides of the cup by fine elastic threads (unfortunately not visible in the images provided). At this minute scale, raindrops falling inside the “nest” have enough force to fling the “eggs” and their threads up and 1 m away from the fruiting body − a small-scale but violent dispersal mechanism! The elastic threads act like the boluses of South American gauchos and wrap around any available obstruction as the “eggs” land, securing them in place.

Cyanthus striatus. Photo: David Catcheside.

The fluted birds nest fungus, Cyathus striatus (Huds.) Willd., also appears occasionally on wood mulch in the Botanic Gardens. The cups are similar in size to those of C. olla but their outer surfaces are covered with brown, shaggy hairs, and the inner surfaces are grooved or fluted, hence the name striatus.

Other birds nest fungi, Nidularia and Crucibulum species, lack elastic threads and have their “eggs” embedded in mucilage, but like Cyathus, rely on raindrops for dispersal.

Six of the oldest plant specimens in South Australia

The Good Living blog of the Department of Environment, Water and Natural Resources published a post on the State Herbarium of South Australia‘s plant collection today, showcasing six important specimens…

http://www.environment.sa.gov.au/goodliving/posts/2016/05/plant-specimens

State Herbarium closed Wednesday – Friday

All staff of the State Herbarium of South Australia are attending the South Australian NRM Science Conference from Wed., 13 Apr. to Fri., 15 Apr. 2016. The Conference also includes a special botany symposium in celebration of the Herbarium’s 60th birthday in 2014/15: Botany 2016—past, present and future. The full conference program and abstract booklet can be downloaded here.

Please note that the State Herbarium is closed during these three days. It will reopen on Mon., 18 Apr. 2016.

13th Australian Bryophyte Workshop

The 2016 Australian Bryophyte Workshop has been announced.

Generally held every two years, the workshops aim to present opportunities for those interested in learning about bryophytes to meet and exchange knowledge in different environments. This year will present the first opportunity for the intrepid to venture into an environment largely unfavourable for bryophytes, the semi-arid fringes of the centre of Australia. This will present people with a different challenge from other workshops — the need to search for the small in size and quantity. Only 109 moss and 28 hepatic taxa are represented in the State Herbarium collections from the Flinders Ranges, but expert eyes may find more!

If you’re interested in attending or just interested in keeping in touch with workshop developments check the meeting’s website. Registrations are open now.