Plants of
South Australia
Eucalyptus cosmophylla
Cup Gum,
Bog Gum
Display all 19 images
Regional Species Conservation Assessments per IBRA subregion.
Least concern
Near threatened
Critically endangered
Data deficient
Coober Pedy
Mount Gambier
Enlarge Map
Copy Map
Copy Map
Display IBRA region text

Botanical art

Kath Alcock paintings: 2

Prior names

Eucalyptus cosmophylla var. leprosula

Eucalyptus cosmophylla var. rostrigera

Eucalyptus cosmophylla f. leprosula

Common names

Cup Gum

Bog Gum


Eucalyptus from the Greek 'eu' meaning well and 'calyptos' meaning covered; alluding to the cap or lid which covers the stamens in the bud. Cosmophylla from the Greek 'cosmos' meaning ornament and 'phyllon' meaning a leaf; referring to the large, ornamental leaves.

Distribution and status

Endemic to South Australia and found on Kangaroo Island and the southern Mount Lofty Rnges, growing on a variety of soils, usually of low fertility in mallee shrubland. Native. Common in South Australia.
Herbarium regions: Northern Lofty, Southern Lofty, Kangaroo Island, Green Adelaide
AVH map: SA distribution map (external link)

Plant description

Multi-stemmed tree to 5 m high or less often single-stemmed and up to 10 m with almost entirely smooth, pale buff-grey with whitish and pinkish areas, shedding in plates. Juvenile leaves narrow- to broadly elliptic, but becoming ovate-orbicular. Adult leaves to 150 mm long and 40 mm wide, slightly oblique, narrow- to broad-lanceolate, thick, dull, grey-green. Flowers in shortly pedunculate or sessile umbels of 3 in the axils of the leaves. Buds to 15 mm long and 10 mm wide, on pedicels 0-3 mm long, obovoid or ellipsoid, bud-cap hemispherical to conical, shortly beaked, usually shorter than the bud-base. Flowers cream. Flowering between July and November. Fruits are large, cup-shaped to cylinder-shaped fruit to 17 mm long and 20 mm wide, usually 2-ribbed with a thick rim, valves broad, usually with the tips just below the rim. Seeds are dark brown to black pyramid-shaped to irregularly-shaped seed to 2 mm long and 2 mm wide, with a wrinkled surface and a narrow wing along the main edge. 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 un-open 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 one collection, the seed viability was high, at 95%. Seeds are non-dormant, viable seed should germinate readily.

Seeds stored:
LocationNo. of seeds
(weight grams)
of plants
Collection number
Collection location
% ViabilityStorage
6,000 (10.2 g)
6,000 (10.2 g)
Kangaroo Island
1-Sep-2004 +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: