Plants of
South Australia
Caladenia formosa
Orchidaceae
Elegant Spider Orchid
Display all 12 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 paintings: 16.

Etymology

Caladenia from the Greek 'callos' meaning beauty and 'aden' meaning a gland, referring to the colourful labellum and the glistening glands at the base of the column that adorn many of the species. Formosa from the Latin 'formosa' meaning beautiful, alluding to the attractive flowers.

Distribution and status

Found in the South-east in South Australia, growing in heathy woodlands in shallow sands, typically in areas that are moist in winter and dry in summer. Also found in Victoria. Native. Rare in South Australia. Very rare in Victoria. Vulnerable in Australia under the EPBC Act.
Herbarium region: South Eastern
NRM region: South East
AVH map: SA distribution map (external link)

Plant description

Annual terrestrial orchid growing from an underground tuber to 50 cm tall with up to three flowers and a single hairy linear leaf to 15 cm long. Flowers are large, with sepals up to 80 mm in length. Colour can vary from pinkish-red to deep blood-red, but is generally uniform. Flowering between September and October. 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 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 two populations consisting of more than 50 individuals in total were recorded in the Geegeela & Binnum areas. Approximately 1,235,000 seeds (0.38 g) were banked from these two populations. Seed viability was low (19%) for the Geegeela collection and ranged between 72% and 93% for the Binnum collection. Seed germination in Caladenia species is difficult without compatible mycorrhizal fungi.

Seeds stored:
  Hide
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
2 pods22-Nov-2005M. Worley
South Eastern
1-Nov-2016N/C-80°C
BGA6,000 (0.002 g)716-Oct-2013DJD2780
South Eastern
1-Nov-201619%-80°C
BGA700,000 (0.213 g)11 podsC. Dickson
South Eastern
1-Nov-201693%-80°C
30-Nov-2004Anna?
South Eastern
1-Nov-2016N/C-80°C
BGA150,000 (0.045 g)44-Jul-2005C. Dickson
South Eastern
1-Nov-201672%-80°C
BGA380,000 (0.118 g)234-Jul-2005C. Dickson
South Eastern
1-Nov-201677%-80°C
30-Nov-2004Anna?
South Eastern
1-Nov-2016N/C-80°C
BGA77,900 (0.028 g)222-Nov-2018DJD3851
South Eastern
24-Apr-2019N/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.