Seeds of South Australia
Zygophyllum crassissimum (Zygophyllaceae)
Thick Twinleaf
List of species for Zygophyllum
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Seed collecting:
October to December
Herbarium regions:
North Western, Lake Eyre, Gairdner-Torrens
NRM regions:
Alinytjara Wilurara, South Australian Arid Lands
IBRA regions
Roxby (GAW07)Gawler
 Rare   (IUCN: RA d(i,ii))   [likes gypeous breakaways]
Simpson Desert (SSD02)Simpson Strzelecki Dunefields
 Rare   (IUCN: RA d(i,ii))   [edge of range; restricted]
Breakaways (STP01)Stony Plains
 Near Threatened   [likes gypeous breakaways]
Oodnadatta (STP02) 
 Rare   (IUCN: RA d(i,ii))   [likes gypeous breakaways]
Macumba (STP05) 
 Rare   (IUCN: RA d(i,ii))   [likes gypeous breakaways]
Witjira (STP06) 
 Rare   (IUCN: RA d(i,ii))   [likes gypeous breakaways]
RSCA map:
Regional Species Conservation Assessments per IBRA subregion. Please click the thumbnail map.
AVH map:
Australian distribution map (external link)
SA Census:
Census of South Australian plants (external link)     [genus Zygophyllum]
Name derivation:
Zygophyllum from the Greek 'zygon' meaning pair and 'phyllon' meaning leaf; referring to the pair of leaflets making up each leaf. Crassissimum means very fleshy; referring to the texture of the plant.
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.
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.
Fruit type:
Yellow-brown broad-oblong, four segmented capsule with paper wings, each segment with 1-2 seeds.
Seed type:
Dark brown to black ovoid seed to 4 mm long and 2 mm wide and a long yellow aril on one edge.
Embryo type:
Spatulate fully developed.
Seed collecting:
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.
Seed cleaning:
Place the capsules in a tray and leave to dry for 1 to 2 weeks, depending on the greeness of the fruit. 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:
From two collections, the seed viability were high, ranging from  95% to 100%.
Seeds stored:
LocationNo. of seeds
(weight grams)
of plants
Collection number
Collection location
% ViabilityStorage
3600 (25 g)
3600 (25 g)
Lake Eyre
1-Jan-201295%+5°C, -18°C
BGA10000 (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:
DateResultT0T50Pre-treatment | Germination medium | Incubator: Photoperiod / Thermoperiod
Sep-148%25 dNA
1% agar;
Incubated under spring/autumn conditions
Sep-144%25 dNA 30% peroxide 15 min, water rinse;
1% agar;
Incubated under winter conditions
Sep-152%25 dNA
1% agar;
Incubated under winter conditions
Sep-140%NANA 30% peroxide 15 min, water rinse;
1% agar;
Incubated under spring/autumn 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)