Prior names
Cyperus pumilus var. nervulosus
Common names
Annual Flat-sedge
Etymology
Cyperus from the Latin 'cyperos' and derived from the Greek 'kypeiros', an ancient Greek name used by Homer and Theophrastus for several plants of this genus. Nervulosus means with little veins.
Distribution and status
Found mainly along the river Murray with scattered records in the central and north-east parts of South Australia, growing on damp sandy soil fringing receding water in lakes and watercourses. Also found in all mainland states. Native. Rare in South Australia. Rare in New South Wales and Victoria. Common in the other states.
Herbarium regions: Lake Eyre, Eastern, Murray
AVH map: SA distribution map (external link)
Plant description
Dwarf tufted annual sedge. Culms trigonous, smooth, to 20 cm high, to 1 mm diameter. Leaves not septate-nodulose, as long as culms or much shorter, to 2 mm wide. Flower-spike simple, of 2–6 branches to 6 cm long, or head-like; spikes short, broad-ovoid, to 4 cm diam.; involucral bracts leaf-like, 2–4 exceeding inflorescence. Spikelets flattened, 5–20 per spike, 5–20 mm long, 2–3 mm wide in side view, 6–54-flowered; rachilla not or scarcely winged, persistent; glumes obtuse, with excurved mucro to 0.7 mm long, with keel 3–5-nerved, sides hyaline, pale yellow- to red rown, 2–2.5 mm long (excluding mucro); stamens 2. Flowers in spring and summer. Fruits are pale brown globular fruit-head in clusters at the terminal of stems. Seeds are dark brown to black ovoid seed to 0.6 mm long and 0.2 mm wide, with a tuberculate surface and covered in a thin whitish transparent layer. Seed embryo type is capitate.
Seed collection and propagation
Collect seeds between December and April. Collect fruits by picking off the mature heads, those turning brown colour and come-off easily. 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. Be careful as the seeds are very small. Seeds are ovid, dark brown to black and hard. 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 one collection, the seed viability was high, at 95%.
| Location | No. of seeds (weight grams) | Number of plants | Date collected | Collection number Collection location | Date stored | % Viability | Storage temperature |
|---|---|---|---|---|---|---|---|
| BGA | 44,000 (0.75 g) | 50 | 11-May-2008 | RJB77864 Lake Eyre | 19-Sep-2008 | 95% | +5°C, -18°C |
| BGA | 45,000 (0.9 g) | 50+ | 28-Feb-2017 | DJD3624 Murray | 1-Nov-2017 | 100% | +5°C, -18°C, -80°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.