Plants of
South Australia
Eucalyptus youngiana
Myrtaceae
Yarldarlba, Large-fruited Mallee,
Ooldea Mallee,
Yarldarlba
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Regional Species Conservation Assessments per IBRA subregion.
Least concern
Near threatened
Rare
Vulnerable
Endangered
Critically endangered
Extinct
Data deficient
Adelaide
Arkaroola
Ceduna
Coober Pedy
Hawker
Innamincka
Marla
Marree
Mount Gambier
Oodnadatta
Renmark
Wudinna
Keith
Yunta
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Botanical art

Kath Alcock painting: 1

Prior names

Eucalyptus pyriformis ssp. youngiana

Eucalyptus pyriformis, partly

Eucalyptus erythrocalyx

Common names

Yarldarlba, Large-fruited Mallee

Ooldea Mallee

Yarldarlba

Etymology

Eucalyptus from the Greek 'eu' meaning well and 'calyptos' meaning covered, alluding to the cap or lid which covers the stamens in the bud. Youngiana named after Jess Young, an explorer who accompanied Ernest Giles during his fourth expedition, making some important botanical collections, including the 'type' specimen.

Distribution and status

Found in the western part of South Australia, growing on deep red sand on dunes an in swales and on outcropping granite monoliths and rocky hillslopes. Also found in Western Australia. Native. Uncommon in South Australia. Uncommon in Western Australia.
Herbarium regions: North Western, Nullarbor, Gairdner-Torrens, Eyre Peninsula
NRM regions: Alinytjara Wilurara, South Australian Arid Lands
AVH map: SA distribution map (external link)

Plant description

Multi-stemmed mallee to 10 m tall with rough, fibrous, dark grey-brown bark on lower stems and smooth, pinkish-grey to creamy bark above. Juvenile leaves ovate to broad-lanceolate, dull, blue-green. Adult leaves to 150 mm long and 40 mm wide, lanceolate to broad-lanceolate, dull, blue-green. Flowers axillary in groups of 3. Buds to 65 mm long and 40 mm wide, coarsely ribbed; bud-cap horn-shaped, equal to the base. Flowers pale yellow to red appearing in autumn to spring. Fruits are very large and woody fruit to 45 mm long and 70 mm wide, coarsely ribbed; disc broad, concave and ascending, valves 4-6 rim level or slightly above. Seeds are brown irregular pyramid-shaped seed to 4.5 mm long and 2.5 mm wide. Seed embryo type is folded.

Seed collection and propagation

Collect seeds between January and December. Collect mature fruits that are dark and hard (difficult to break with a finger nail), with the valves unopen,any time of year. 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. From two collections, the seed viability was average to high, ranging from 65% to 100%. Seeds are non-dormant so viable seed should germinate readily.

Seeds stored:
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LocationNo. of seeds
(weight grams)
Number
of plants
Date
collected
Collection number
Collection location
Date
stored
% ViabilityStorage
temperature
BGA 
MSB
10,200 (152 g)
10,200 (152 g)
50+28-Oct-2004MOL4648
Gairdner-Torrens
31-Mar-2006100%-18°C
BGA21,000 (52.47 g)3019-May-2014DEM7737
North Western
24-Mar-201565%-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:
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