Seeds of South Australia
Prostanthera eurybioides (Labiatae)
Monarto Mintbush
List of species for Prostanthera
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Seed collecting:
November to January
Herbarium regions:
Murray, South Eastern
NRM regions:
South Australian Murray-Darling Basin, South East
IBRA regions
Tintinara (NCP04)Naracoorte Coastal Plain
 Vulnerable   (IUCN: VU D2)   [only at Mt Monster; some recruitment due to intensive man'ment, ~1,000 plants]
Fleurieu (KAN02)Kanmantoo
 Endangered   (IUCN: EN B2ab(i,ii,iii))   (Probable Decline)   [lots of research on this sp; likes granite outcrops; climate sensitive; has been some translocations back into this area, not all successful]
Murray Mallee (MDD02)Murray Darling Depression
 Endangered   (IUCN: EN B2ab(i,ii,iii))   (Definite Decline)   [very little recruitment]
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 Prostanthera]
Name derivation:
Prostanthera from the Greek 'prostheke' meaning an appendage and 'anthera' meaning anther; referring to the spur-like appendage of the anther. Eurybioides means resembling the genus Eurybia (Eurybia is the daughter of Pontus and Gaea, and a sea goddess in Greek mythology); referring to its habit which resembles that of Eurybia lepidophylla.
Distribution:
Endemic to South Australia and found in two disjunct locations near Montato in the Murrayland and Keith in the upper south-east, growing on granite outcrops on sandy loam soils in Eucalyptus mallee woodland.
Status:
Native. Very rare in South Australia.
Plant description:
Low spreading shrub to 1 m high with branches covered in dense curled long hairs. hairy branches. Leaves clustered on short shoots, elliptic to ovate, to 2.5 mm long and 2 mm wide, thick, glabrous or sparsely hairy, base obtuse to rounded, margin entire, apex obtuse. Inflorescence solitary in leave axis with pale purple tubular-shaped flowers with brown or orange spots on the inside. Flowering between August and November.
Fruit type:
Dark brown woody capsule to 2.4 mm long mm long, with up to four segments, surround by the calyx.
Seed type:
Brown oblong seed to 2.2 mm long and 1 mm wide, with a large plug at one end.
Embryo type:
Spatulate fully developed.
Seed collecting:
Collect capsules that are fat and turning brown, either individually or by running your fingers along a stem with numerous capsules.

The collection and storage of seeds for this threatened species in 2016, which is potentially impacted by the plant pathogen Phytophthora cinnamomi, was supported through funding from the Australian Government’s Threat abatement plan for disease in natural ecosystems caused by Phytophthora cinnamomi. A total of three populations occurring in native remnant vegetation on private property in the Monarto region were collected and banked (25,000+ seeds). A sample of this collection will be used to propagate 1,500 plants for a recovery project in 2018 with the support of Natural Resources SA Murray-Darling Basin. 

Seed cleaning:
Place the capsules in a tray and leave to dry for one to two weeks. Then rub the capsules gently with a rubber bung to dislodge the seeds. Use a sieve to separate 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 five collections, the seed viability were high, at 100%.
Seed germination:
This species has physiological dormancy that needs to be overcome for the seed to germinate.
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA700 (4.12 g)1218-Nov-2004PJA 86
Southern Lofty
28-Mar-2006-18°C
BGA8470 (9.32 g)5024-Nov-2006CSO4
South Eastern
1-Aug-2007100%+5°C, -18°C
BGA4400 (6.3 g)30-4011-Dec-2006PJA147
South Eastern
1-Aug-2007100%+5°C, -18°C
BGA1008 (0.963 g)3517-Jan-2006PJA121
Murray
1-Aug-2007100%-18°C
BGA 
MSB
13250 (19.04 g)
13250 (19.04 g)
8030-Dec-2004DJD53
South Eastern
1-Aug-2007100%/100%-18°C
BGA4800 (4.8 g)30-4024-Nov-2006CSO5
South Eastern
1-Aug-2007100%+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-1385%14 d42 d dry heat 80°C oven 10 min, 30% hydrogen peroxide 10 min, water rinse, 500 mg/L gibberellic acid + 10% smoke water 24 h;
filter paper over moist sand;
Incubated under spring/autumn conditions
Sep-1385%14 d42 d dry heat 80°C oven 10 min, 30% hydrogen peroxide 10 min, water rinse, 500 mg/L gibberellic acid 24 h;
filter paper over moist sand;
Incubated under spring/autumn conditions
Sep-1380%28 d63 d dry heat 80°C oven 10 min, 30% hydrogen peroxide 10 min, water rinse, 10% smoke water 24 h;
filter paper over moist sand;
Incubated under spring/autumn conditions
Aug-1375%14 d42 d 30% hydrogen peroxide 10 min, water rinse, 500 mg/L gibberellic acid 24 h;
filter paper over moist sand;
Incubated under spring/autumn conditions
Aug-1774%2135 dry heat 80°C oven for 10 min, 30% hydrogen peroxide for 10 min, water rinse, 500 mg/L gibberellic acid for 24 h;
1% agar;
Incubated under spring/autumn conditions
Aug-1365%7 d14 d dry heat 80°C oven 10 min, 30% hydrogen peroxide solution 10 min, water rinse, remove plug;
filter paper over moist sand;
Incubated under spring/autumn conditions
Aug-1350%42 d56 d dry heat 100°C oven 2 min, 30% hydrogen peroxide 10 min, water rinse, 10% smoke water 24 h;
filter paper over moist sand;
Incubated under spring/autumn conditions
Aug-1350%28 d70 d dry heat 100°C oven 2 min, 30% hydrogen peroxide solution 10 min, water rinse, 500 mg/L gibberellic acid 24 h;
filter paper over moist sand;
Incubated under spring/autumn conditions
Sep-1340%28 dNA dry heat 80°C oven 10 min, 30% hydrogen peroxide 10 min, water rinse;
filter paper over moist sand;
Incubated under spring/autumn conditions
Aug-1315%42 dNA dry heat 100°C oven 2 min, 30% hydrogen peroxide 10 min, water rinse;
filter paper over moist sand;
Incubated under spring/autumn conditions
Aug-130%NANA 30% hydrogen peroxide 10 min, water rinse, leached in water 7 d;
filter paper over moist sand;
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)