Botanical art
Prior names
Andropogon sericeus
Andropogon affinis
Dichanthium affine
Common names
Silky Blue-grass
Queensland Blue-grass
Etymology
Dichanthium from the Greek 'dicha' meaning in two and 'anthos' meaning flowers; alluding to the two kinds of spikelet pairs in the raceme. Sericeum from Latin meaning silky; alluding to the white silky hairs of the inflorescence.
Distribution and status
Found mainly in the northern part of South Australia and in the Mount Lofty Ranges, growing in open grassland on clay soils. Also found in all mainland states. Native. Common in South Australia. Common in the other states.
Herbarium regions: North Western, Lake Eyre, Gairdner-Torrens, Flinders Ranges, Eastern, Eyre Peninsula, Northern Lofty, Southern Lofty, Green Adelaide
AVH map: SA distribution map (external link)
Plant description
Tufted, usually strongly glaucous perennials, culms erect, sometimes branched near base, to 80 cm high, nodes fringed with spreading hairs to 3 mm long. Leaves glabrous (rarely with scattered hairs), blade to 15 cm long and 4 mm wide, ligule truncate, 1–2 mm long. Flower-spike with 2–6 racemes, each 1–6 cm long, digitately arranged, densely silky-hairy; pedicellate spikelets sterile (an empty lemma within the pair of glumes); sessile spikelets resembling pedicellate ones, to 4 mm long (excluding awn), subtended by a tuft of silky hairs up to two-thirds as long as spikelet; lower glume, narrow-elliptic, 7–11-nerved, flattened dorsally, fringed with long hairs around the margin in the upper part; upper glume narrower, keeled, 3-nerved; sterile lemma about half as long as glumes, hyaline; fertile lemma inconspicuous, appearing as a slightly broader area toward the base of the brown, twice bent, twisting awn 2–3 cm long. Flowering between November and April. Dichanthium sericeum ssp. humilius differ from this subspecies by being an annual and having spikelets fewer nerves on the lower glume (5-7) and a shorter racemes (less than 4 cm long). Fruits are whitish brown silking fruit-spike. Seeds are brown grain to 3 mm long and 1 mm wide. Seed embryo type is lateral.
Seed collection and propagation
Collect seeds between December and June. Use hands to gently strip seeds off the mature seed spike that are fluffy and straw colour. Mature seeds will come off easily. Alternatively, you can break off the whole seed spike. Place the seeds/spike in a tray and leave to dry for two weeks. No further cleaning is required if only seed collected. If seed spikes collected, use hand to strip off the mature 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 one collection, the seed viability was low, at 35%.
| Location | No. of seeds (weight grams) | Number of plants | Date collected | Collection number Collection location | Date stored | % Viability | Storage temperature |
|---|---|---|---|---|---|---|---|
| BGA MSB | 43,200 (39.8 g) 43,200 (39.8 g) | 100+ | 24-Dec-2005 | KHB27 Southern Lofty | 9-Aug-2006 | 35% | -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.