Botanical art
Prior names
Zygophyllum marliesiae
Zygophyllum prismatothecum, partly
Common names
Marlies Square-fruit Twinleaf
Square-fruit 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. Marliesiae named after Mrs Marlies Eichler, wife of Hansjoerg Eichler who always shared in his work, but her contribution is largely unsung.
Distribution and status
Endemic to South Australia and is confined to the Lake Eyre region, growing in a wide range of ecological niche including salt pans, samphire flood plains, limestone formations associated with mound springs, gypseous flats and sand hills. Native. Uncommon in South Australia.
Herbarium regions: Lake Eyre, Gairdner-Torrens
NRM region: South Australian Arid Lands
AVH map: SA distribution map (external link)
Plant description
Spreading annual herb to 15 cm high. Leaves petiolate, with 2 pairs of leaflets. Leaflets succulent, elliptic, to 8 mm long and 8.5 mm wide, continuous with petiole and not articulated at base, rounded at the apex. Inflorescence solitary at each node with yellow flowers. This species is related to Roepera prismatotheca and can be distinguished predominantly on fruiting characters, it differs by its longer pedicels in flower and fruit, the elliptic rather than rectangular fruits and by the much shorter apical appendages on the fruit (which continuous with the angle of the fruit wall and not constricted at their base as in R. prismatotheca). Flowering between June and November. Fruits are yellow-green rounded-oblong capsule to 11 mm long, with 4-angles and 4-cells, sides continuous into 4 falcate, appendages at apex. Seeds are brown ovoid to 3.5 mm long and 1.8 mm wide. Seed embryo type is spatulate fully developed.
Seed collection and propagation
Collect seeds between August 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.
Location | No. of seeds (weight grams) | Number of plants | Date collected | Collection number Collection location | Date stored | % Viability | Storage temperature |
---|---|---|---|---|---|---|---|
BGA MSB | 9,600 (21.4 g) 9,600 (21.4 g) | 100+ | 22-Sep-2016 | JRG453 Lake Eyre | 1-Nov-2017 | 100% | -18°C |