Seeds of South Australia
Eucalyptus arcana (Myrtaceae)
Carpenter Rocks Gum
List of species for Eucalyptus
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Seed collecting:
January to December
Herbarium region:
South Eastern
NRM region:
South East
IBRA region
Bridgewater (NCP01)Naracoorte Coastal Plain
 Vulnerable   (IUCN: VU D2)   [more trees found 10km south - N Bonney]
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 Eucalyptus]
Name derivation:
Eucalyptus from the Greek 'eu' meaning well and 'calyptos' meaning covered; alluding to the cap or lid which covers the stamens in the bud. Arcana from the Latin 'arcanus' meaning mysterious and secret; alluding to the location of the type specimen being hidden in dense scrub.
Distribution:
Found at one location in the lower South-east in South Australia near Carpenter Rocks, growing on low rises on red clay-loam with outcropping limestone in dense tall shrubland. Also found at a second location in Victoria.
Status:
Native. Very rare in South Australia. Very rare in Victoria.
Plant description:
Single- or several-stemmed low straggly tree to 6 m tall with rough, fibrous, grey to grey-brown bark to smaller branches, and smooth, grey to cream bark above. Juvenile leaves broad-lanceolate tapering to the base, bright green. Adult leaves to 120 mm long and 35 mm wide, lanceolate, glossy, green. Flowers axillary in groups of 7, with very short or lacking individual stalks. Buds to 7.5 mm long and 5.5 mm wide, egg-shaped, bud-cap cone-shaped equal to the base. Flowers white appearing in February.
Fruit type:
Rounded to cone-shaped fruit to 7 mm long and 8 mm wide, disc descending to almost level, valves 3 or 4 above the rim.
Seed type:
Dark brown to black ovoid seed to 2.5 mm long and 1.5 mm wide, with wrinkled surface.
Embryo type:
Folded.
Seed collecting:
Collect mature fruits that are dark and hard (difficult to break with a finger nail), with the valves un-open any time of year.
Seed cleaning:
Leave the fruits in a breathable container in a dry room for one to two weeks. This allows the valves on the fruit to open and release the seeds. Separate the seeds by placing all the materials into a bucket and shaking it to dislodge the seeds. Pass the material through a sieve to separate the unwanted material. The finer material will contain both seeds (soft) and frass (hard) usually distinguishable from each other but can be very similar in shape and colour. With finer sieves, the seeds can be separated from the frass but this is not essential for storage or propagation. 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 one collection, the seed viability was low, at 45%.
Seed germination:
Seeds are non-dormant, viable seed should germinate readily.
Seeds stored:
LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA 
MSB
16500 (8.73 g)
8500 (4.73 g)
307-Mar-2007DJD778
South Eastern
1-Aug-200745%-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
July 2015100%7d7d None
1% water agar
12 hr dark/12 hr light  /  20 °C constant
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)