Botanical art
Prior names
Baumea gunnii
Cladium gunnii
Common names
Slender Twig-sedge
Slender Twig-rush
Etymology
Machaerina from the Latin 'machaera' meaning a bent dagger or sword, and the feminine diminutive suffix '-ina", referring to the shape of the leaves of some species (formally Baumea named after Antoine Baume (1728 - 1804), a French chemist and inventor). Gunnii named after Ronald Campbell Gunn (1808-1881), a British botanist and legislator in Launceston, Tasmania.
Distribution and status
Found on Kangaroo Island, southern Mount Lofty Ranges and the lower South-east in South Australia, growing in wet heathlands and swampy woodlands. Also found in Queensland, New South Wales, Victoria and Tasmania. Native. Rare in South Australia. Rare in Queensland and Tasmania. Uncommon in the other States.
Herbarium regions: Murray, Southern Lofty, Kangaroo Island, South Eastern, Green Adelaide
AVH map: SA distribution map (external link)
Plant description
Slender tufted perennial sedge with very short rhizome. Culms to 100 cm high and 1.5 mm diameter, slender, rigid, terete, nodeless, striate, glabrous or minutely scabrous to smooth. Leaves to 1.5 mm diameter, basal; blade culm-like, as long as to slightly exceeding culm; sheath reddish or straw-coloured (but then usually with reddish tinges). Inflorescence an interrupted-oblong in outline, narrow, erect, to 60 cm long and 1.5 cm diameter, dull red-brown to grey-brown with spikelets pointing outwards. Flowers in spring and summer. Fruits are slender red-brown drooping heads. Seeds are orange-brown, ovoid nut to 3 mm long and 2 mm wide, smooth and shiny surface. Seed embryo type is capitate.
Seed collection and propagation
Collect seeds between November and March. Collect whole heads that are brown, containing dark hard seeds. Not all heads will contain seeds. Place the heads in a tray and leave to dry for one to two weeks. Then rub the heads with a rubber bung to dislodge the seeds. Use a sieve to separate any unwanted material. Store the seeds with a desiccant such as dried silica beads or dry rice, in an air tight container in a cool and dry place available. Seed viability is variable depending on maturity of seeds when collected. This species is generally difficult to germinate, it has morphophysiological dormancy and complex germination requirements.
| Location | No. of seeds (weight grams) | Number of plants | Date collected | Collection number Collection location | Date stored | % Viability | Storage temperature |
|---|---|---|---|---|---|---|---|
| MSB | 1,780 (5.25 g) | 50+ | 22-Mar-2006 | DJD440 Southern Lofty | |||
| BGA | 219 (0.74 g) | 1 | 23-Nov-2007 | RJB75916 South Eastern | 19-Sep-2008 | 20% | -18°C |
| BGA | 4,300 (17.55 g) | 10 | 12-Dec-2018 | DJD3843 South Eastern | 24-Apr-2019 | 80% | -18°C |
| BGA | 3,400 (16.15 g) | 10 | 31-Jan-2019 | TST1415 Southern Lofty | 24-Apr-2019 | 80% | -18°C |
Number of plants: This is the number of plants from which the seeds were collected.
Collection location: The Herbarium of South Australia's region name.
% Viability: Percentage of filled healthy seeds determined by a cut test or x-ray.