Seeds of South Australia
Eucalyptus bicostata (Myrtaceae)
Southern Blue Gum
List of species for Eucalyptus
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Seed collecting:
January to December
Herbarium region:
Northern Lofty
NRM region:
Northern and Yorke
IBRA region
Olary Spur (FLB03)Flinders Lofty Block
 Endangered   (IUCN: EN D)   (Probable Decline)   [1 pop of few 100 trees at Mt Bryan; 100's of years old; very long-lived spp. Climate change a threat. Common in eastern states.]
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. Bicostata from the Latin 'bi' meaning two and 'costatus' meaning ribbed; referring to the two opposite ribs on each bud and fruit.
Distribution:
Found only on Mount Bryon in South Australia, growing in open grassy woodland on steep upper, south-facing slopes. Also found in New South Wales and Victoria.
Status:
Native. Very rare in South Australia. Common in the other states.
Plant description:
Single- to multi-stemmed tree to 18 m high with smooth, reddish-tan to grey to cream bark throughout or sometimes with some loose plate-like rough bark at the base. Juvenile leaves ovate to elliptical, lacking stalk, wavy, waxy, dull, greyish. Adult leaves to 400 mm long and 50 mm wide, lanceolate, glossy, dark green. Flowers in groups of 3 in axils of the leaves with very short or no stalk. Buds to 18 mm long and 14 mm wide, waxy, bud-cap warty, equal in length or shorter than the 2-ribbed base. Flowers cream appearing in summer and autumn.
Fruit type:
round fruit to 17 mm long and 20 mm wide, lacking individual stalks, 2-ribbed, waxy when young, disc broad and ascending, valves 4 or 5 above the rim.
Seed type:
Dark brown to black ovoid seed to 2 mm long and 1.5 mm wide.
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 two collections, the seed viability were high, ranging from 90% to 95%.
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
BGA5800 (11.67 g)419-Sep-2006RJB69410
Northern Lofty
1-Aug-200790%-18°C
BGA 
MSB
17500 (33.7 g)
17500 (33.7 g)
2523-Sep-2007RJB73888
Northern Lofty
19-Sep-200895%-18°C
PJA1811-Jan-2012-18°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 201526%7dNA None
1% water agar
12 hrs light / 12 hrs dark  /  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)