Euclid - Online edition

Eucalyptus astringens subsp. astringens


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Brown mallet

Classification

Eucalyptus | Symphyomyrtus | Bisectae | Glandulosae | Erectae | Pedicellatae

Nomenclature
Eucalyptus astringens (Maiden) Maiden, Crit. Revis. Eucalyptus 7: 55 (1924) subsp. astringens.

E. occidentalis var. astringens Maiden, J. W. Austral. Nat. Hist. Soc. 3: 186 (1911). T: Broomhill, W.A., Dec. 1909, J.H.Maiden s.n.; holo: NSW; iso: K.
Description
Mallet to 15 m tall, rarely to 25 m. Lignotuber absent.
Bark smooth throughout, pale shiny grey over salmon to brown, but often with small curled flakes of dead bark adhering to lower trunk.
Branchlets with oil glands in the pith.
Juvenile growth (coppice or field seedlings to 50 cm): stems rounded in cross-section; juvenile leaves always petiolate, alternate, ovate-lanceolate, 6–10 cm long, 2–6 cm wide, dull, grey-green.
Adult leaves alternate, petioles 1–2.5 cm long; blade lanceolate, rarely falcate, 6–14 cm long, (0.8)1–2.5(3.5) cm wide, base tapering to petiole, margin entire, apex finely pointed, concolorous, green, at least slightly glossy, side-veins at an acute or wider angle to midrib, reticulation sparse to moderate (or sometimes dense) and clear, intramarginal vein present, oil glands numerous, ± round, island and intersectional.
Inflorescence axillary unbranched, spreading to pendulous, peduncles narrowly to broadly flattened, 1.2–3.2 cm long, buds 7 per umbel, pedicellate (pedicels 0.2–0.9 cm long). Mature buds stubby to slightly elongated, 1.5–2 cm long, 0.5–0.7 cm wide, swollen at or just below the join, scar present (outer operculum shed early), inner operculum horn-shaped but usually blunt, ca 1.2–2 times the length of the hypanthium, stamens erect, anthers oblong, versatile, dorsifixed, dehiscing by longitudinal slits, style long and straight, stigma blunt, locules 3 or 4, the placentae each with 4 vertical rows of ovules. Flowers cream to pale lemon.
Fruit pedicellate (pedicels 0.2–0.7 cm long), cupular to campanulate or obconical, 0.7–1.2 cm long, 0.6–1 cm wide, disc level at first then descending, valves 3 or 4, held at rim level or slightly exserted.
Seeds blackish brown, 1–2.5 mm long, ovoid to flattened-ovoid, dorsal surface shallowly and clearly reticulate, hilum ventral.

Cultivated seedlings (measured at node 10): cotyledons Y-shaped (bisected); stems rounded in cross-section; leaves always petiolate, opposite for 4 or 5 nodes then alternate, deltoid to ovate, 4–8 cm long, 2–6.5 cm wide, dull, green to blue-green.
Flowering Time

Flowering has been recorded in July, August, September, October and November.

The timber of E. astringens is very hard and strong. The species has been cultivated for use in tool handles, mining timber, farm purposes and fuel. The bark has a high tannin content.

Eucalyptus astringens subsp. astringens has been recorded as having become naturalised near Glenmore in Victoria, spreading from soil conservation plantings.

Notes

Eucalyptus astringens is a mallet species endemic to Western Australia, distributed south-east of Perth from Brookton, south to near Albany and east to Hopetoun. The adult leaves are glossy green and buds have a blunt operculum.

It belongs in Eucalyptus subgenus Symphyomyrtus section Bisectae subsection Glandulosae because the buds have an operculum scar, cotyledons are bisected and branchlets have oil glands in the pith. Within this large subsection (ca 80 species) E. astringens is closely related to a group of mallets and mallees (series Erectae subseries Pedicellatae) recognised by the glossy green leaf surface, leaves with many oil glands but not obscuring the secondary venation, peduncles long and flattened or terete, inflorescences spreading to pendulous and buds with operculum longer than the hypanthium and erect stamens arising from a narrow staminophore.

E. astringens is distinguished from its relatives by its mallet habit, smooth bark and stubby, blunt buds with operculum only one to two times the length of the hypanthium and its campanulate fruit. E. thamnoides has similar buds but differs in the consistent mallee habit. Other related species, viz. the rough-butted tree of freshwater creeks and depressions, E. occidentalis, rough-barked mallee E. aspratilis, smooth-barked mallee E. sporadica and rough-butted tree of saline sites, E. sargentii, all have more slender buds with elongated opercula.

There are two weakly distinguished subspecies:

E. astringens subsp. astringens
This subspecies is a taller mallet with buds usually longer than 1.5 cm. It is always found on well-drained lateritic breakaways and occurs from Brookton to near Albany, and east as far as Hyden and Newdegate.

E. astringens subsp. redacta
A small mallet with smaller buds and fruits than in subsp. astringens (buds usually shorter than 1.5 cm) , occurring in southern subcoastal areas between Kambellup, Jerramungup and Ravensthorpe exending to the coast between Albany and Bremer Bay; on lateritic breakaways.

Origin of Name
Eucalyptus astringens: Latin astringens, astringent, referring to extracts from the bark.

subsp. redacta: Latin redactus, reduced, referring to the habit, buds and fruit compared to subsp. astringens .
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