Eucalyptus gardneri subsp. ravensthorpensis

Blue mallet

Eucalyptus | Symphyomyrtus | Bisectae | Glandulosae | Levispermae | Levispermae

Eucalyptus gardneri subsp. ravensthorpensis Brooker & Hopper, Nuytsia 8: 149 (1991).

T: Ravensthorpe Range, ca. 5 km E of Ravensthorpe, 800m ENE of Highway 1 along Carlingup Road, then 800 m NNW to revegetating gravel pit, 10 Apr. 1991, S.D.Hopper 7929; holo: PERTH; iso: CANB, MEL, NSW.

Mallet to 10 m tall. Lignotuber absent.
Bark smooth throughout, shedding in short curly flakes, satiny grey over salmon-pink.
Branchlets with few or no glands in pith.
Juvenile growth (coppice or field seedlings to 50 cm): not seen.
Adult leaves alternate, petioles 1–2 cm long; blade lanceolate, 6–10.5 cm long, 1–2.7 cm wide, base tapering to petiole, margin entire, concolorous, dull, blue-grey, side-veins greater than 45° to midrib, reticulation usually moderate, intramarginal vein remote from margin, oil glands irregularly shaped, island and intersectional.
Inflorescence axillary unbranched, peduncle widening apically, 1–2 cm long, buds ?9 or 11 per umbel, pedicellate (pedicels 0.4–0.6 cm long). Mature buds fusiform and curved (1.5–2 cm long, 0.4–0.5 cm wide), scar present, operculum conical to horn-shaped, two to three times as long as hypanthium and equal to it in width at the join, few outer stamens erect, most stamens variably deflexed, anthers oblong, versatile, dorsifixed, dehiscing by longitudinal slits, style long and straight, stigma blunt to rounded, locules 3, the placentae each with 4 vertical rows of ovules. Flowers pale lemon.
Fruit pedicellate (pedicels 0.2–0.3 cm long), usually cylindrical to barrel-shaped, 1 cm long, 0.5–0.6 cm wide, disc descending vertically, valves 3, near rim level.
Seeds pale brown to straw-coloured, 0.8–1.5 mm long, usually sub-spherical, surface smooth, hilum ventral/terminal.

Cultivated seedlings (measured at ca node 10): cotyledons Y-shaped (bisected); stems rounded (?triangular) in cross-section; leaves always petiolate, sometimes shortly so, opposite 3 or 4 nodes then alternate, ovate, 6–9 cm long, 2–5 cm wide, dull green.

Flowering has been recorded in January, June and December.

Eucalyptus gardneri is a mallet species endemic to Western Australia, mainly south-east of Perth from south of Williams to the Ravensthorpe Range, and also a small occurrence near Cadoux north-east of Perth; usually on lateritic ridges or slopes. The bark is smooth apart from imperfectly shed, curling, red-brown flakes. The leaves are dull, blue-grey and the whole crown is recognisable for its bluish colour.

It belongs in Eucalyptus subgenus Symphyomyrtus section Bisectae subsection Glandulosae because the cotyledons are bisected and the buds have an operculum scar and the branchlets have oil glands in the pith (though in this case usually few or sometimes none). Within this subsection E. gardneri is one of a group of species that form series Levispermae subseries Levispermae characterised by having smooth spherical seed, a peduncle that widens apically, and buds that are narrowly fusiform with some stamens erect, others variably deflexed, usually dull blue-grey to grey-green adult leaves, and few, if any, oil glands in the pith.

E. gardneri is distinguished from the closely related smooth-barked small-leaved mallet E. densa subsp. densa by having much larger lanceolate leaves (to 2.3 cm wide) and also the obvious persistent curls of bark. E. gardneri differs from the smooth-barked mallee E. pluricaulis in habit and bark features.

There are two subspecies:

E. gardneri subsp. gardneri
Found over the major part of the distribution of the species and characterised by the very long attenuate opercula.

E. gardneri subsp. ravensthorpensis
This form occurs only at the eastern end of the distribution of the species, in the Ravensthorpe Range, and is characterised by the shorter opercula and slightly fatter buds.

Eucalyptus gardneri: after Charles Austin Gardner (1896–1970). Charles Gardner's botanical career began in 1920 when he was appointed as a botanical collector in the Forests Department of Western Australia. His first major contribution to botany was as botanist on the Kimberley Exploration Expedition in 1921. In 1924 he transferred to the botany branch of the Department of Agriculture and in 1928 became the Government Botanist and Curator of the Herbarium in Western Australia, a position he held until his retirement in 1962.

subsp. ravensthorpensis: from Ravensthorpe, the only locality of occurrence.