Eucalyptus jutsonii subsp. jutsonii

Eucalyptus | Symphyomyrtus | Bisectae | Destitutae | Micrantherae | Bakerianae

Eucalyptus jutsonii Maiden, J. & Proc. Roy. Soc. New South Wales 53: 61 (1919) subsp. jutsonii

T: Comet Vale, W.A., Dec. 1916, J.T.Jutson 216; holo: NSW; iso: CANB, MEL.

Mallee to 6 m tall. Forming a lignotuber.
Bark rough over part or all of stems rarely extending to small branches, fibrous, grey, smooth above pinkish to grey-brown.
Branchlets lacking oil glands in the pith.
Juvenile growth (coppice or field seedlings to 50 cm): stems rounded in cross-section; juvenile leaves sessile to very shortly petiolate, alternate, linear, 6–10 cm long, 0.1–0.3 cm wide, dull, grey-green to blue-grey.
Adult leaves alternate, petioles to 0–0.8 cm long; blade linear, 7.5–13.5 cm long, 0.3–0.6(0.7) cm wide, base tapering to petiole, margin entire, apex pointed, concolorous, glossy, green, thick, side-veins acute or obscure, reticulation moderate to dense and broken, intramarginal vein present or incomplete, oil glands conspicuous, intersectional.
Inflorescence axillary unbranched, peduncles 0.2–0.7(0.9) cm long, buds 7, pedicellate (pedicels 0.1–0.3 cm long). Mature buds fusiform to ovoid (0.6–0.9 cm long, 0.3–0.4 cm wide), scar present (outer operculum shed early), inner operculum conical, a few outer stamens with erect filaments but with anthers deflexed, the remaining filaments inflexed to varying extent, anthers reniform to cuboid, versatile, dorsifixed, dehiscing by short oblique slits, style long and straight, arising between three prominent lobes on the ovary roof, stigma rounded to tapering, ovary roof with sutures passing radially through lobes, locules 3, the placentae each with 4 vertical rows of ovules. Flowers cream.
Fruit pedicellate (pedicels 0.1–0.4 cm long), truncate-globose, 0.4–0.5(0.8) cm long, 0.5–0.7(0.8) cm wide, disc more or less level, valves 3, slightly exserted and with apical notch containing stub of style base.
Seeds brown, 0.8–2 mm long, flattened-ovoid, dorsal surface with 2 longitudinal furrows and shallow or obscure reticulation, hilum ventral.

Cultivated seedlings (measured at node 10): cotyledons Y-shaped (bisected); stems rounded in cross-section; leaves sessile to very shortly petiolate (ca 1 mm), opposite for 8 to 10 nodes then alternate, linear, 4–8(12) cm long, 0.2–0.8 cm wide, dull, grey-green.

Flowering has been recorded in February, March, November and December.

Eucalyptus jutsonii is a mallee endemic to the arid zone of Western Australia and of very restricted distribution north of Kalgoorlie, from the Comet Vale area east to Carr Boyd Rock, with another disjunct population occurring north-east of Perenjori. It occurs on sandy sites, usually dunes with mallee scrub. The bark is rough on the stems and usually the branches, often as small as 3 cm diameter. The adult leaves are glossy green and strikingly linear and the buds axillary and bi-conic in shape.

There are two subspecies:

E. jutsonii subsp. jutsonii occurs north of Kalgoorlie and has adult leaves 0.3–0.7 cm wide, and fruit 0.4–0.8 cm long and 0.5–0.8 cm wide.

E. jutsonii subsp. kobela occurs only north-east of Perenjori, has adult leaves 0.1-0.3 cm wide, and fruit 0.3–0.5 cm long and 0.5–0.6 cm wide

Eucalyptus jutsonii belongs in Eucalyptus subgenus Symphyomyrtus section Bisectae subsection Destitutae because buds have two opercula, cotyledons are Y-shaped and branchlets lack oil glands in the pith. Within this subsection E. jutsonii is closely related to only three other species, E. micranthera (from near Esperance, Western Australia), E. bakeri (from northern New South Wales and southern Queensland) and E. mannensis (from central Australia to Shark Bay area of Western Australia), all of which have a peculiar three-lobed ovary roof in which the base of the style is inserted, and leaves with conspicuous intersectional oil glands.

Within its natural range E. jutsonii is distinguished from other mallee species by the combination of mallee habit, rough stems, dark green linear adult leaves, unusual ovary roof and versatile anthers.

Eucalyptus jutsonii: after John Thomas Jutson (1874–1959). From 1911–1918 John Jutson was a geologist with the Geological Survey of Western Australia. Part of his work included reporting on the mining centres of the North Coolgardie goldfields. In 1916 he published the first edition of his Physiography of Western Australia. He later studied law and remained in a legal practice in Melbourne until his retirement in 1952. He always retained his interest in Geology, updating the Physiography of Western Australia in 1934 and contributed 24 papers to the Royal Society of Victoria.