Seeds of South Australia
Orthoceras strictum (Orchidaceae)
Horned Orchid
List of species for Orthoceras
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Seed collecting:
January to February
Herbarium regions:
Flinders Ranges, Eyre Peninsula, Northern Lofty, Murray, Yorke Peninsula, Southern Lofty, Kangaroo Island, South Eastern
NRM regions:
Adelaide and Mount Lofty Ranges, Eyre Peninsula, Kangaroo Island, Northern and Yorke, South Australian Murray-Darling Basin, South East
IBRA regions
Bridgewater (NCP01)Naracoorte Coastal Plain
 Endangered   (IUCN: EN B2ab(i,ii,iii))   (Probable Decline)
Lucindale (NCP03) 
 Endangered   (IUCN: EN B2ab(i,ii,iii))   (Probable Decline)   [good colony in Desert Camp CP in 2010]
Tintinara (NCP04) 
 Endangered   (IUCN: EN B2ab(i,ii,iii))   (Probable Decline)
Kangaroo Island (KAN01)Kanmantoo
 Rare   (IUCN: RA d(ii))   (Probable Decline)
Fleurieu (KAN02) 
 Rare   (IUCN: RA d(ii))   (Probable Decline)
Mount Lofty Ranges (FLB01)Flinders Lofty Block
 Rare   (IUCN: RA d(ii))   (Probable Decline)
Broughton (FLB02) 
 Critically Endangered   (IUCN: CR D)   (Definite Decline)   [Last recorded in 1975, not recorded since. Presumed extinct.]
Southern Flinders (FLB04) 
 Critically Endangered   (IUCN: CR D)   (Definite Decline)   [In critically low numbers, definite decline.]
Eyre Hills (EYB03)Eyre Yorke Block
 Endangered   (IUCN: EN D)   (Probable Decline)
Talia (EYB04) 
 Endangered   (IUCN: EN D)   (Probable Decline)
Eyre Mallee (EYB05) 
 Endangered   (IUCN: EN D)   (Probable Decline)
Lowan Mallee (MDD04)Murray Darling Depression
 Vulnerable   (IUCN: VU D1)   (Probable Decline)
RSCA map:
Regional Species Conservation Assessments per IBRA subregion. Please click the thumbnail map.
AVH map:
Australian distribution map (external link)
SA Census:
Census of South Australian plants (external link)     [genus Orthoceras]
Name derivation:
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 botanically to mean very straight, upright or narrow.
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, from 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.
Plant description:
Terrestrial orchid to 80 cm tall with up to 9 flowers on a brittle dark stem. Leaves are basal, 2-5, grasslike, 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.
Fruit type:
Brown papery ellipsoid capsule.
Seed type:
Very small brown ellipsoid seed with a long cylindrical translucent brown mesh-like covering.
Seed collecting:
Collect fat capsules as they start to dry and turn brown. Pods will split and release the seeds quickly and will require monitoring. To increase the chances of collecting mature pods, it is recommended that a small breathable bag (ie. Organza bags) be used to enclose the developing capsules.
Seed cleaning:
Place the capsules in a container that will hold fine seeds and leave to dry for a few weeks or until the capsule 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.
Seed viability:
For the NVC South East Orchid Project two populations consisting of more than 30 individuals in total was 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:
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.