Eucalyptus kruseana

Bookleaf mallee

Eucalyptus | Symphyomyrtus | Bisectae | Glandulosae | Kruseanae

Eucalyptus kruseana F.Muell., Austral. J. Pharm. 10: 233 (1895).

T: near Fraser Ra., 160 km N of Israelite Bay, W.A., 1895, J.D.Batt s.n.; holo: MEL; iso: K.

Eucalyptus morrisonii Maiden, J. W. Austral. Nat. Hist. Soc. 3: 44 (1910). T: 50–150 miles [80–240 km] E of Kalgoorlie, W.A., May 1909, H.Deane s.n.; holo: NSW; iso: CANB, K, MEL.

Mallee or shrub to 3 m tall. Forming a lignotuber.
Bark rough, thin, firmly held on base of trunks, fibrous, dark grey, smooth above bronze to coppery and dark grey, shedding in ribbons along the branches, rarely smooth throughout.
Branchlets white waxy, with oil glands present in the pith.
Mature crown never developing adult leaves, all leaves from low coppice growth to the reproductive crown are juvenile in form, i.e. sessile, opposite, blade more or less orbicular to cordate, 1–2.5 cm long, 1–2.5 cm wide, base amplexicaul, margin entire to subcrenulate, apex rounded or less commonly notched, concolorous, dull, glaucous (grey), side-veins greater than 45° to midrib, moderately reticulate, intramarginal vein remote from margin, oil glands island.
Inflorescence axillary unbranched, peduncles 0.4–1 cm long, buds 7 per umbel, pedicellate (pedicels 0.1–0.3 cm long). Mature buds ovoid (0.7–1 cm long, 0.3–0.5 cm wide), glaucous at least on pedicel and base of bud, scar present, operculum conical, stamens inflexed, anthers cuboid, versatile, dorsifixed, dehiscing by longitudinal slits, style long and straight, stigma blunt or slightly rounded, locules 4(5), the placentae each with 4 vertical rows of ovules. Flowers greenish yellow.
Fruit pedicellate (pedicels 0.1–0.4 cm long), barrel-shaped to cupular or truncate-globose, 0.5–0.9 cm long, 0.5–0.7(0.8) cm wide, disc descending, valves 4(5), about rim level.
Seeds brown, 0.7–1.5 mm long, ovoid or flattened-ovoid, scarcely angular, dorsal surface shallowly reticulate, hilum ventral.

Cultivated seedlings (measured at ca node 10): cotyledons Y-shaped (bisected); stems rounded in cross-section, warty, glaucous; leaves sessile and opposite throughout, orbicular to cordate, 1–2.5 cm long, 1–2.5 cm wide, waxy white-grey (green beneath the wax).

Flowering has been recorded in February, March, May and July.

E. kruseana is a popular ornamental in drier parts of southern Australia and in central Australia because of its mallee habit, flower colour and unusual leaves.

A straggly mallee endemic to Western Australia, restricted to three areas, Cardunia Rocks and near Erayinia Hill east of Kalgoorlie, and Binyarinyinna Rock east of Widgiemooltha. The stems are smooth and the mature crown composed of small, sessile, orbicular to cordate, glaucous, crowded juvenile leaves.

Eucalyptus kruseana belongs to Eucalyptus subgenus Symphyomyrtus section Bisectae subsection Glandulosae because the cotyledons are bisected, buds have an operculum scar and the branchlets have oil glands in the pith. Within this subsection (of ca 80 species) E. kruseana is not closely related to any particular species because of its unusual crown, its inflexed stamens and its greenish yellow flowers.

At the Cardunia Rock and Binyarinyinna Rock sites it is associated with E. brachyphylla, a more erect mallee with petiolate, sub-opposite, ovate leaves making up the mature crown. E. brachyphylla has been shown to be a hybrid between E. kruseana and co-occurring E. loxophleba subsp. lissophloia. E. brachyphylla is white-flowered—see that species for more details. 

Eucalyptus kruseana: after John Kruse (1822–1895). John Kruse was a pharmacist born in Germany. He settled and practiced in Melbourne, initially in Richmond and then later in Bourke Street in the city. He took a keen interest in his profession and was active in the establishment of the College of Pharmacy. He was Director and a lecturer at the college from 1883 to 1886. After retiring from the college he recommenced his practice in Hawthorn.