Eucalyptus eremicola subsp. eremicola

Eucalyptus | Symphyomyrtus | Bisectae | Destitutae | Subulatae | Oleaginae

Eucalyptus eremicola Boomsma subsp. eremicola, S. Austral. Naturalist 50: 28 (1975)

T: South Australia:125 km E of Serpentine Lake, (28°30'S 130°22'E), 28 June 1967, J.Johnson s.n.; holo: AD.

Mallee to 4 m tall. Forming a lignotuber.
Bark usually rough on the lower half of the stems, flaky to ribbony, grey to brown, smooth bark yellow-brown over powdery white or grey-white.
Branchlets lacking oil glands in the pith.
Juvenile growth (coppice or field seedlings to 50 cm): not seen.
Adult leaves alternate, petiole 0.7–1.7 cm long; blade linear to narrowly lanceolate, 4.5–10 cm long, 0.6–1.7 cm wide, base tapering to petiole, concolorous, glossy, green, side-veins acute, densely reticulate, intramarginal vein parallel to and just within margin, oil glands numerous and mostly intersectional.
Inflorescence axillary unbranched, peduncles 0.5–1 cm long, buds 9 to 15 per umbel, pedicels 0.2–0.3 cm long. Mature buds ovoid (0.6–0.8 cm long, 0.3–0.4 cm wide), scar present, operculum conical, stamens irregularly flexed, anthers adnate to weakly versatile, basifixed, globoid, dehiscing by lateral pores, style long, stigma tapered, locules 3 or 4, the placentae each with 4 vertical ovule rows. Flowers white.
Fruit pedicellate (pedicels 0.1–0.3 cm long), truncate-globose, 0.3–0.6 cm long, 0.4–0.6 cm wide, disc descending, valves 3 or 4, valve tips strongly exserted due to fragile style remnants.
Seeds dull brown to grey, 1.2–2 mm long, ovoid or flattened-ovoid, occasionally with shallow longitudinal furrows on otherwise smooth dorsal surface, hilum ventral.

Cultivated seedlings (measured at node 10): cotyledons Y-shaped (bisected); stems appearing rounded to square in cross-section, but more or less five-sided; leaves opposite, sessile and linear for the first 2 to 3 nodes then alternate, subsessile to very shortly petiolate and becoming narrowly elliptical to narrowly lanceolate further up the stem, 2.5–6 cm long, 0.5–1 cm wide, dull grey-green.

Flowering has been recorded in January, July and September.

Eucalyptus eremicola is a mallee species of the Great Victoria Desert of South Australia and Western Australia, extending north-west into the Little Sandy Desert and stretching in the west as far as the Sandstone and Leonora districts of the Goldfields of Western Australia. The bark is normally rough on the lower part of the stems. It has small buds with conical opercula and small fruit with the exserted style remnants usually persistent.

Eucalyptus eremicola 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. eremicola is part of a large taxonomic series Subulatae  further characterised by globoid basifixed anthers, grey smooth seeds with shallow longitudinal furrows, and fruit with persistent exserted style remnants. Series Subulatae is divided principally into four subseries based on the juvenile leaves, one with spiral, crowded seedling phyllotaxis (subseries Spirales), another with decussate and decurrent seedling leaves (subseries Decurrentes), another with decussate non-decurrent seedling leaves (subseries Decussatae), and a fourth to which E. eremicola belongs with disjunct, petiolate seedling leaves (subseries Oleaginae).

The other members of the subseries Oleaginae  are E. kochii, E. longissima and E. ultima. Within the subseries, E. kochii and E. longissima differ by having rough bark over most of the stem. E. longissima differs further by normally being a much larger plant. E. ultima is mostly smooth-barked (sometimes with rough bark for ca 0.5 m) and has very narrow linear seedling leaves.

Within its area of occurrence, E. eremicola should only be confused with E. socialis. E. socialis has bigger buds and fruit, the buds normally with a long beaked operculum.

There are two subspecies:

E. eremicola subsp. eremicola
Common in the red sands of the Great Victoria Desert. It is distinguished from subsp. peeneri by its narrow, very glossy green adult leaves.

E. eremicola subsp. peeneri
A mallee from the Great Victoria Desert of South Australia and Western Australia, extending west to the Meekathara region of Western Australia. It is often of sprawling habit with stems usually rough on the lower half. The adult leaves are usually dull, blue-green to blue-grey, but can mature to semi-glossy blue-green, particularly in the western populations where it grows slightly taller than it does in the Great Victoria Desert. This western form was formerly described as E. sublucida.

Intergrades between both subspecies are common in parts of the Great Victoria Desert.

Eucalyptus eremicola: Greek eremi-, desert and Latin cola, dweller.