Notched Twinleaf
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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
Display IBRA region text
Northern Flinders (FLB05) | Flinders Lofty Block | Rare (IUCN: RA d(ii)) |
Gawler Lakes (GAW03) | Gawler | Rare (IUCN: RA d(ii)) |
Arcoona Plateau (GAW04) | | Least Concern |
Kingoonya (GAW05) | | Rare (IUCN: RA d(ii)) |
Torrens (GAW06) | | Near Threatened |
Roxby (GAW07) | | Least Concern |
Tallaringa (GVD05) | Great Victoria Desert | Rare (IUCN: RA d(i,ii)) |
Strzelecki Desert (SSD05) | Simpson Strzelecki Dunefields | Near Threatened |
Breakaways (STP01) | Stony Plains | Least Concern |
Oodnadatta (STP02) | | Least Concern |
Murnpeowie (STP03) | | Rare (IUCN: RA d(i,ii)) |
Witjira (STP06) | | Least Concern |
Baltana (STP07) | | Least Concern |
Sturt Stony Desert (CHC02) | Channel Country | Rare (IUCN: RA d(i,ii)) |
Coongie (CHC06) | | Rare (IUCN: RA d(ii)) |
Everard Block (CER03) | Central Ranges | Rare (IUCN: RA d(i,ii)) |
Pedirka (FIN04) | Finke | Least Concern |
Northern Flinders (FLB05) | Flinders Lofty Block | Rare (IUCN: RA d(ii)) |
5 of 8 subregions | Gawler | Least Concern , Near Threatened , Rare |
Tallaringa (GVD05) | Great Victoria Desert | Rare (IUCN: RA d(i,ii)) |
Strzelecki Desert (SSD05) | Simpson Strzelecki Dunefields | Near Threatened |
5 of 7 subregions | Stony Plains | Least Concern , Rare |
2 of 4 subregions | Channel Country | Rare |
Everard Block (CER03) | Central Ranges | Rare (IUCN: RA d(i,ii)) |
Pedirka (FIN04) | Finke | Least Concern |
Botanical art
Kath Alcock painting: 1
Prior names
Zygophyllum emarginatum
Zygophyllum ammophilum, partly
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. 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.
Location | No. of seeds (weight grams) | Number of plants | Date collected | Collection number Collection location | Date stored | % Viability | Storage temperature | BGA | 12,000 (28.81 g) | 50+ | 21-Sep-2016 | JRG446 Lake Eyre | 1-Nov-2017 | 100% | -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
Date | Result | T0 | T50 | Pre-treatment | Germination medium | Incubator: Photoperiod / Thermoperiod |
Jul-17 | 90% | 7 | 7 |
30% hydrogen peroxide for 10 min, water rinse, seed coat nicked with scalpel; 1% agar; Incubated under winter conditions |
Jul-17 | 30% | 7 | NA |
seed coat nicked with scalpel; 1% agar; Incubated under winter conditions |
Jul-17 | 3% | 14 | NA |
30% hydrogen peroxide for 10 min, water rinse; 1% agar; Incubated under winter conditions |
Jul-17 | 0% | 0 | NA |
leached in water 24 h; 1% agar; Incubated under winter conditions |
Result: Maximum percentage of germination observed.
T0: Number of days before first germinant observed.
T50: Number of days to achieve 50% germination.
Pre-treatment: The initial treatment that the seeds received prior to placement on germination media.
Germination medium: The substrate that seeds were placed on for the duration of the germination experiment.
Incubator conditions:
Photoperiod: The duration of light exposure that the seeds were subject to during a 24 hour period.
Thermoperiod: The constant or diurnal temperatures that seeds were subject to during a 24 hour period.
Winter conditions: 15°C 20 h (3am→11pm); 5°C 4 h (11pm→3am) / 10 h light (8am→6pm); 14 h dark (6pm→8am)
Spring/Autumn conditions: 22°C 12 h (8am→8pm); 10°C 12 h (8pm→8am) / 12 h light (8am→8pm); 12 h dark (8pm→8am)
Summer conditions: 30°C 14 h (6am→8pm); 15°C 10 h (8pm→6am) / 14 h light (6am→8pm); 10 h dark (8pm→6am)