Common names
Twin-leaf Mallee
Blue Mallee
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. Gamophylla from the Greek 'gamos' meaning united and 'phyllon' meaning a leaf; referring to the joined juvenile leaf pairs of the species.
Distribution and status
Found in the far north-west corner of South Australia, growing on red sandplains and rocky hillslopes in mallee shrubland. Also found in Western Australia, Northern territory and Queenslands. Native. Uncommon in South Australia. Uncommon in Queensland. Common in the other states.
Herbarium region: North Western
AVH map: SA distribution map (external link)
Plant description
Multi-stemmed mallee to 7 m high with rough, hard, stringy-fibrous, yellow-brown to grey bark below and smooth, yellow-tan to cream bark above. Juvenile leaves oppsoite, sessile, glabrous, ovate, pruinose, dull, blue-green to greyish. Mature crown consist of juvenile leaves to 100 mm long and 20 mm wide, sessile or on stalk to 6 mm long, ovate to lanceolate, pruinose, dull, greyish. Flowers terminal or axillary clusters or few-branched panicles in groups of 3. Buds to 7 mm long and 45 mm wide, on very short stalk, cylinder-shaped to pear-shaped, bud-cap half-domed to flattened, much shorter than the base. Flowers cream appearing in winter after rain. Fruits are narrowly cone-shaped to cylinder-shaped fruit to 16 mm long and 7 mm wide, smooth, pruinose, disc descending and often white, valves 3 to 4 below rim. Seeds are dark brown to black irregularly pyramidal seed to 2.5 mm long and 2 mm wide, finely wrinkled. 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. Seeds are non-dormant, viable seed should germinate readily.