Plants of
South Australia
Roepera emarginata
Notched Twinleaf
Display all 18 images
Regional Species Conservation Assessments per IBRA subregion.
Least concern
Near threatened
Critically endangered
Data deficient
Coober Pedy
Mount Gambier
Enlarge Map
Copy Map
Copy Map
Display IBRA region text

Botanical art

Kath Alcock painting: 1

Prior names

Zygophyllum emarginatum

Zygophyllum ammophilum, partly


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. Emarginata means with a notched margin; referring to the apex of the leaflets which is notched.

Distribution and status

Found in the north and north-eastern parts of South Australia, growing on rocky or gravelly hills or rises, breakaways, gibber plains and Chenopod-rich plains. Also found in the Northern Territory, Queensland and New South Wales. Native. Common in South Australia. Uncommon in New South Wales. Common in the other states.
Herbarium regions: North Western, Lake Eyre, Gairdner-Torrens, Flinders Ranges
NRM regions: Alinytjara Wilurara, South Australian Arid Lands
AVH map: SA distribution map (external link)

Plant description

Spreading annual herb to 10 cm high with glabrous or inconspicuously hairy ridged stems. Leaves opposite, succulent, green, petiolate, and divided into 2 leaflets. Leaflets articulate at base, cuneate to narrow-obcordate, to 16 mm long and 7 mm wide, apex mostly distinctly emarginate. Stipules present between pairs of opposite leaves. Inflorescence small with yellow flowers, 4 sepals, 4 petals to 4.5 mm long. Flowering between June and September Fruits are pale brown capsule to 8 mm long, strongly 4-angled (but not winged) in cross-section, truncate-angular apically. Seeds are semi-flat brown shiny, ovoid to 3.2 mm long and 2 mm wide, with a reticulated surface. Seed embryo type is spatulate fully developed.

Seed collection and propagation

Collect seeds between November and January. 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:
LocationNo. of seeds
(weight grams)
of plants
Collection number
Collection location
% ViabilityStorage
BGA12,000 (28.81 g)50+21-Sep-2016JRG446
Lake Eyre
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: