Seeds of South Australia
Juncus prismatocarpus (Juncaceae)
Branching Rush
List of species for Juncus
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Seed collecting:
February to May
Herbarium regions:
Murray, Southern Lofty
NRM regions:
Adelaide and Mount Lofty Ranges, South Australian Murray-Darling Basin
IBRA regions
Fleurieu (KAN02)Kanmantoo
 Endangered   (IUCN: EN B2ab(i,ii,iii,iv,v))   (Probable Decline)   [only 1 pop known; comes up after disturbance; grazing, weeds - threats]
Mount Lofty Ranges (FLB01)Flinders Lofty Block
 Data Deficient   [1 record from Warrawong - could be planted; likes swamps & peat bogs]
Murray Mallee (MDD02)Murray Darling Depression
 Endangered   (IUCN: EN B2ab(i,ii,iii); D)   (Probable Decline)
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 Juncus]
Name derivation:
Juncus from the Latin 'jungere' meaning to tie or bind; referring to the use of the rushes for weaving and basketry. Prismatocarpus from the Latin 'prismaticus' meaning prism-shaped and the Greek 'carpos' meaning fruit; referring to the trigonous-ovoid fruit capsule. 
Distribution:
Found at Mypolonga and Mount Compass in South Australia, growing along the edges of creeks and rivers near permanent water. Also found in Queensland, New South Wales, Victoria, Tasmania, New Zealand and Asia.
Status:
Native. Endangered in South Australia. Uncommon in Tasmania and common in other states.The SA Seed Bank collected and banked 80,000 seeds from a single known extant population near Mount Compass in 2017 with the support of the Natural Resources Adelaide & Mount Lofty Ranges
Plant description:
Erect perennial rush to 40 cm tall with flattened leaves up the culm and dichotomous branching flower heads. Leaves hollow with multiple longitudinal tubes within. Inflorescence clusters with many pale brown flowers at the end of multi-branching stem. Flowers possibly throughout the year but mainly in summer.
Fruit type:
Clusters of trigonous-ovoid light brown capsules.
Seed type:
Tiny brown seed to 0.6 mm long and 0.3 mm wide, with fine reticulated surface.
Embryo type:
Broad.
Seed collecting:
Collect fruits either by picking off the mature heads, those turning brown and come-off easily or break-off the whole spikes.
Seed cleaning:
Place the heads in a tray and leave to dry for one to two weeks. Then rub the heads with a rubber bung to dislodge the seeds. Use a sieve to separate any unwanted material. Be careful, as the seeds are very small. Seeds are brown and hard. 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, at 100%.
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA 
MSB
54000 (0.7 g)
54000 (0.7 g)
50-6027-Apr-2006TST004
Murray
1-Aug-2006100%+5°C, -18°C
BGA163000 (2.35 g)50+12-Mar-2010DJD1809
Southern Lofty
Jun-2010100%-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
Jul-17100%728 dry heat 100°C oven for 10 min, 30% hydrogen peroxide for 20 min, water rinse, 500 mg/L gibberellic acid for 44 h;
1% agar;
Incubated under summer conditions
Jul-1783%1428 30% hydrogen peroxide for 20 min, water rinse, 500 mg/L gibberellic acid for 44 h;
1% agar;
Incubated under spring/autumn conditions
Jul-1780%1414 30% hydrogen peroxide for 20 min, water rinse, 500 mg/L gibberellic acid for 44 h;
1% agar;
Incubated under summer conditions
Jul-1777%1428 dry heat 100°C oven for 10 min, 30% hydrogen peroxide for 20 min, water rinse, 500 mg/L gibberellic acid for 44 h;
1% agar;
Incubated under winter conditions
Jul-1767%2828 30% hydrogen peroxide for 20 min, water rinse, 500 mg/L gibberellic acid for 44 h;
1% agar;
Incubated under winter conditions
Jul-1753%742 dry heat 100°C oven for 10 min, 30% hydrogen peroxide for 20 min, water rinse, 500 mg/L gibberellic acid for 44 h;
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)