Botanical art
Common names
River Mint
Etymology
Mentha, a Latin name of a Greek nymph who was turned into a mint plant. Australis, means of, or from the south, or refers to Australia.
Distribution and status
Found in the eastern side of South Australia, south to the Murray River, growing on clay-rich soils, particularly near rivers and creeks, or in clay depressions in the floodplains of the River Murray. Also found in all States except in Western Australia. Native. Common in South Australia. Uncommon in the Northern Territory and Tasmania. Common in the other States.
Herbarium regions: Lake Eyre, Gairdner-Torrens, Flinders Ranges, Eastern, Murray, Southern Lofty, Green Adelaide
AVH map: SA distribution map (external link)
Plant description
Soft perennial herb, often sprawling, sometimes erect. Leaves ovate, often angular-ovate or lanceolate and paired; to 20 mm long and 12 mm wide; glabrous or with short hairs. Inflorescence in dense clusters, with 3-12 tubular, white or pink flowers in the leaf axils. Flowering between November and February. Fruits are dense clusters of papery brown capsules. Seeds are dark brown to black ovoid seed to 1 mm long and 0.7 mm wide. Seed embryo type is spatulate.
Seed collection and propagation
Collect seeds between December and April. Collect individual capsules that are turning brown and contain hard seeds, or break off whole stems with numerous brown capsules. Place the capsules in a tray and leave to dry for a week. Then rub the capsules gently with a rubber bung to dislodge the seeds from the capsules. Use a sieve to separate the unwanted material. Some seeds will be empty. Use an aspirator to siphon off the lighter, non-viable seeds from the heavier good seeds. 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. From two collections, the seed viability was high, ranging from 80% to 85%.
| Location | No. of seeds (weight grams) | Number of plants | Date collected | Collection number Collection location | Date stored | % Viability | Storage temperature |
|---|---|---|---|---|---|---|---|
| BGA | 910 (0.13 g) | 24-Feb-2009 | TST717 Southern Lofty | 20-Jul-2009 | 80% | -18°C | |
| BGA | 12,000 (1.61 g) | 50+ | 8-Dec-2013 | DJD2660 Murray | 27-Feb-2014 | 85% | -18°C |
| BGA | 1,800 (0.363 g) | 20-Jan-2021 | Ben Simon - LAP Southern Lofty | 28-Jun-2021 | 55% | -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.