Botanical art
Common names
Horned Orchid
Etymology
Orthoceras, from the Greek 'orthos', meaning upright and 'ceras', horn, referring to the erect lateral sepals. Strictum, from the Latin 'strictus', from 'stringere', meaning to draw tight, often used botanically to mean very straight, upright or narrow.
Distribution and status
Very widely distributed through much of South Australia, with small to extensive populations found in a variety of habitats that receive greater than 300 ml rainfall annually,; grows in open forest, grassland and mallee. Also found in Queensland, New South Wales, Victoria, Tasmania, New Zealand and New Caledonia. Native. Common in South Australia. Uncommon in Tasmania and Queensland. Common in the other States.
Herbarium regions: Flinders Ranges, Eyre Peninsula, Northern Lofty, Murray, Yorke Peninsula, Southern Lofty, Kangaroo Island, South Eastern, Green Adelaide
AVH map: SA distribution map (external link)
Plant description
Terrestrial orchid to 80 cm tall with up to 9 flowers on a brittle dark or yellow stem. Leaves are basal, 2-5; grass-like, linear to filiform, to 30 cm long. Flowers are yellowish green to dark brown, fleshy with a hooded dorsal sepal; lateral sepals filiform to 25 mm long; small hidden petals, and a labellum with a central yellow patch. Flowering between November and January. Fruits are brown papery ellipsoid capsule. Seeds are very small brown ellipsoid seed with a long cylindrical translucent brown mesh-like covering.
Seed collection and propagation
Collect seeds between January and February. Collect stout capsules as they start to dry and turn brown. Pods will split and quickly release the seeds, so will require monitoring. To increase the chances of collecting mature pods, it is recommended that a small breathable bag (eg. Organza bags) be used to enclose the developing capsules. Place the capsules in a container that will hold fine seeds and leave to dry for a few weeks or until the capsules split., then carefully hold the capsule and tap it gently to release the 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, refrigerator or in liquid nitrogen. For the NVC South East Orchid Project, two populations of more than 30 individuals in total were recorded from Comaum Native Forest Reserve and Geegeela area. Approximately 40,000 seeds (0.28 g) were banked from this population. Seed viability ranged from 50% to 82%. Seed germination in orchid species is difficult in the absence of symbiotic mycorrhizal fungi. More research is needed to understand the seed germination requirements in Orthoceras species.
| Location | No. of seeds (weight grams) | Number of plants | Date collected | Collection number Collection location | Date stored | % Viability | Storage temperature |
|---|---|---|---|---|---|---|---|
| BGA | 320,000 (0.265 g) | 7 | 12-Dec-2013 | JRG88 South Eastern | 1-Nov-2016 | 95% | -80°C |
| BGA | 20,000 (0.016 g) | 1 | K. Brewer South Eastern | 1-Nov-2016 | 50% | -80°C | |
| BGA | 27,000 (0.022 g) | K. Brewer South Eastern | 1-Nov-2017 | N/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.