Plants of
South Australia
Prasophyllum frenchii
Orchidaceae
Slaty Leek-orchid
Display all 7 images
Regional Species Conservation Assessments per IBRA subregion.
Least concern
Near threatened
Rare
Vulnerable
Endangered
Critically endangered
Extinct
Data deficient
Adelaide
Arkaroola
Ceduna
Coober Pedy
Hawker
Innamincka
Marla
Marree
Mount Gambier
Oodnadatta
Renmark
Wudinna
Keith
Yunta
Enlarge Map
Copy Map
Copy Map
Display IBRA region text

Botanical art

Kath Alcock painting: 1.

Etymology

Prasophyllum from the Greek ‘prason’ meaning a leek and ‘phyllon’ meaning a leaf, referring to the leek-like orchid leaf. Frenchii named after G. French, who collected the type specimen from 'between the Yarra and the Dandenong Ranges' in 1889.

Distribution and status

Found only in the lower South-east in South Australia, growing in grassland, heathland and open forest on well-drained or water-retentive sand or clay loams. Also found in New South Wales and Victoria. Native. Very rare in South Australia. Very rare in New South Wales. Rare in Victoria. Endangered in Australia under the EPBC Act.
Herbarium region: South Eastern
NRM region: South East
AVH map: SA distribution map (external link)

Plant description

Terrestrial orchid with a robust erect flowering stem to 60 cm tall. Single leaf-blade to 20 cm long and 10 mm diameter, green, apex lax, often withered at flowering. Inflorescence a loose to quite dense spike which is well exserted from the leaf with 20–65, fragrant, green to reddish brown or red flowers. Sepals to 8 mm long, dorsal sepal ovate, lateral sepals free, lanceolate, nearly parallel, erect to recurved. Petals to 7 mm long, oblong-elliptic, blunt. Labellum trullate, to 6 mm long, green or red-tinted, recurved at right angles past the middle and the base margins slightly crinkled. Flowering between October and November. Fruits are pale brown papery ellipsoid capsules along the spike. Seeds are very small orange-brown ellipsoid seed with a long cylindrical translucent brown mesh-like covering.

Seed collection and propagation

Collect seeds between December and January. 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. 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. For the NVC South East Orchid Project one population consisting of more than 50 individuals in total was recorded from Piccaninnie Ponds area. Approximately 540,000 seeds (0.7 g) were collected & banked from this population in 2012 in addition to the 2008 collections annotated below. Seed viability was 85%. More research is needed to understand the seed germination requirements of Prasophyllum species. Recent in-vitro symbiotic seed germination research in Prasophyllum (including P. frenchii) by Marc Freestone & Noushka Reiter at RBGV has yielded some early positive results.

Seeds stored:
  Hide
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA 
MSB
1,000,000 (0.71 g)
1,000,000 (0.71 g)
9-Jan-2008CRD6
South Eastern
1-Nov-2016N/C-18°C, -80°C
BGA100,000 (0.065 g)35-Jan-2007CRD3
South Eastern
1-Nov-2016N/C-80°C
BGA540,000 (0.802 g)50 pods4-Jul-2005C. Dickson
South Eastern
1-Nov-201685%-80°C
BGA82,000 (0.59 g)613-Dec-2017DJD3690
South Eastern
30-Jun-2018N/C-18°C
Location: BGA — the seeds are stored at the Adelaide Botanic Gardens, MSB — the seeds are stored at the Millennium Seed Bank, Kew, England.
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.