Plants of
South Australia
Roepera crassissima
Zygophyllaceae
Thick Twinleaf
Display all 13 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

Prior names

Zygophyllum crassissimum

Common names

Thick Twinleaf

Etymology

Roepera (formally Zygophyllum which is from the Greek 'zygon' meaning pair and 'phyllon' meaning leaf; referring to the pair of leaflets making up each leaf) is named after Johannes August Christian Roeper (1801 -1885), a German botanist and physician. Crassissima means very fleshy; referring to the texture of the plant.

Distribution and status

Found in the north central part of South Australia, growing on gypseous flats and rocky rises. Also found in the Northern Territory. Native. Rare in South Australia. Rare in the Northern Territory.
Herbarium regions: North Western, Lake Eyre, Gairdner-Torrens
AVH map: SA distribution map (external link)

Plant description

Erect perennial subshrub with a thick stem and thick spreading branches, to 60 cm high. Leaves very fleshy with leaflets very broad, obliquely obovate-cuneate, to 4 cm long, appearing continuous with a very short petiole, glaucous. Flowers orange with 4 sepals and 4 petals. Flowering between June and October. Fruits are yellow-brown broad-oblong, four segmented capsule with paper wings, each segment with 1-2 seeds. Seeds are dark brown to black, ovoid to 4 mm long and 2 mm wide with a long yellow aril on one edge. Seed embryo type is spatulate fully developed.

Seed collection and propagation

Collect seeds between October and December. Collect semi-dried and dried capsules by running your hands through the stems of the plant. Mature fruits will come off easily and will have a hard and dark seed inside each segment. Place the capsules in a tray and leave to dry for 1 to 2 weeks, depending on how green the fruit is. Then rub the dried capsules to dislodge the seeds. Use a sieve to remove the unwanted material. 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. Seed viability is usually high.

Seeds stored:
  Hide
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA 
MSB
3,600 (25 g)
3,600 (25 g)
100+14-Dec-2010MJT298
Lake Eyre
1-Jan-201295%+5°C, -18°C
BGA10,000 (89.8 g)2-Nov-2013TST1189
Lake Eyre
24-Mar-2015100%+5°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.
Germination table:
  Display