Eucalyptus globulus subsp. maidenii

Maiden's gum

Eucalyptus | Symphyomyrtus | Maidenaria | Euryotae | Globulares | Euglobulares

Eucalyptus globulus subsp. maidenii (F.Muell.) J.B.Kirkp., J. Linn. Soc., Bot. 69: 101 (1975).

Eucalyptus maidenii F.Muell., Proc. Linn. Soc. New South Wales ser. 2, 4: 1020 (1890). T: Colombo, NSW, June 1887, W.Bäuerlen s.n.; lecto: NSW, fide J.H.Maiden, Crit. Revis. Eucalyptus 2: 265 (1913); isolecto: MEL.

Tree to 50 m tall. Forming a lignotuber.
Bark smooth apart from base which has persistent slabs, shedding in large strips and slabs; smooth bark white, cream, grey, pink, yellowish or pale creamy orange, often with ribbons of decorticated bark in the upper branches; branchlets occasionally glaucous.
Juvenile growth (coppice or field seedlings to 50 cm): stem square in cross-section and prominently winged, glaucous; juvenile leaves opposite and sessile for many pairs, elliptical to oblong then ovate to lanceolate or falcate, 4–11 cm long, 1.7–6 cm wide, base amplexicaul, margin sometimes crenulate, usually discolorous with upper surface green or slightly glaucous and the lower surface copiously white-waxy.
Adult leaves alternate, petiole 1.5–3.7 cm long; blade lanceolate to falcate, 12–35.5 cm long, 1.2–4 cm wide, base tapering to petiole, concolorous, dull or glossy, green, side-veins greater than 45° to midrib, densely reticulate, intramarginal vein parallel to and well removed from margin, oil glands island and intersectional.
Inflorescence axillary unbranched, peduncle flattened, 0.8–2.5 cm long, buds 7 per umbel, stoutly pedicellate (pedicels 0.3–0.8 cm long). Mature buds ± clavate to pyriform, the hypanthium narrowly obconical, 0.8–1.1 cm long, 0.5–0.7 cm wide, slightly ribbed, green or glaucous, smooth or warty, scar present, operculum beaked to flattened and umbonate, stamens inflexed, anthers cuboid to oblong, versatile, dorsifixed, dehiscing by longitudinal slits (non-confluent), style long, stigma blunt or tapered, locules 3 or 4, the placentae each with 4 vertical ovule rows. Flowers white.
Fruit usually on pedicels to 0.7 cm long, rarely sessile, obconical, 0.5–0.8 cm long, 0.6–1 cm wide, slightly ribbed longitudinally or not so, sometimes glaucous, disc raised-convex or disc level, valves 3 or 4, exserted or near rim level.
Seeds black, brown or grey, 1.5–2.5 mm long, ovoid to flattened-ovoid or slightly cuboid, often lacunose, dorsal surface shallowly pitted, hilum ventral.

Cultivated seedlings (measured at ca node 10): cotyledons bilobed; stems square in cross-section and prominently winged also, glaucous; leaves sessile, opposite for many nodes, oblong to elliptical or ovate-lanceolate, 7–10 cm long, 2.5–5 cm wide, amplexicaul, margin entire or subcrenulate, apex pointed, glaucous to blue.

Flowering has been recorded in March.

Forms of Eucalyptus globulus have commonly become naturalised in areas away from the species natural distribution in many places in southern Australia.

Eucalyptus globulus is a forest tree species that is widespread in the ranges and subcoastal forests of eastern New South Wales as far north as the Carrai Plateau, eastern, southern and central Victoria, and Tasmania. It is notable for the very conspicuous seedlings, coppice and young saplings with square stems and large, glaucous, oblong to ovate sessile juvenile leaves. The trunks are mostly smooth and the adult leaves are large, bright glossy green and usually falcate.

There are four subspecies: 

E. globulus subsp. globulus
Of largely lowland distribution in Tasmania, including King Island and islands of the Furneaux group and Rodondo Island, and coastal and subcoastal distribution on the southernmost extremities in Victoria. It has a single, large, sessile, glaucous, warty bud per axil (rarely in threes) and the solitary fruit 1.4–2.7 cm wide.

E. globulus subsp. bicostata
A montane and tableland subspecies in eastern New South Wales occurring as far north as the Carrai Plateau, and in Victoria mostly on the slopes of the Great Dividing Range from Orbost in the east west to the Pyrenees, and with a single very old population in South Australia on Mt Bryan north of Burra. It has similar sessile buds to subsp. globulus, but they are slightly smaller and occur in threes, and fruit (1)1.3–2.2 cm wide.

E. globulus subsp. pseudoglobulus
Mainly in Victoria, from the coastal ranges in east Gippsland but with inland populations at Lerderderg Gorge and north of Toongabbie, and also in Nadgee Nature Reserve, New South Wales. It is morphologically close to subsp. bicostata but differs from that subspecies in having narrower fruit: 0.9–1.2(1.6) cm wide in subsp. pseudoglobulus and often at least the central bud of the 3-flowered umbel being shortly pedicellate (buds always sessile in subsp. bicostata).

E. globulus subsp. maidenii
Occurs in subcoastal ranges of far south-eastern New South Wales and far eastern Victoria and has smaller, pedicellate buds in sevens, often not glaucous, but still with the warty, umbonate operculum typical of the group.

Intergradation commonly occurs between subsp. globulus, bicostata and pseudoglobulus where they come into contact,  and with populations in southern Victoria it may be impossible to attribute a specimen to any particular subspecies. Also the natural distribution of subsp. globulus in Victorian and Tasmanian forests has undoubtedly been confused by forestry plantings in the twentieth century.

Eucalyptus globulus belongs in Eucalyptus subgenus Symphyomyrtus section Maidenaria, a large group of species more or less restricted to south-eastern Australia, characterised by bilobed cotyledons, simple axillary inflorescences, buds with two opercula, stamens with versatile anthers and flattened seeds with a ventral hilum. Within this section, E. globulus belongs in series Globulares subseries Euglobulares, having large, sessile, glaucous, juvenile leaves opposite for many pairs on square, winged stems, buds solitary or in clusters of three or seven and fruit with prominent disc partly covering valves.

Eucalyptus globulus: Latin globulus, a globe, a ball, referring to the fruit shape.

subsp. maidenii: after Joseph Henry Maiden (1859–1925). In 1881 Joseph Maiden was appointed first curator at the Technological Museum Sydney, where he remained until 1896. In the same year he was appointed Government Botanist of New South Wales and Director of the Botanic Gardens, Sydney, where he remained until 1924. When Maiden took over this position, the state had no herbarium, no collection of local flora, no museum and no library of botanical works, a situation he quickly rectified. Maiden is one of the great names in the study of Eucalyptus. He is the author of the monumental eight-volume publication, A Critical Revision of the Genus Eucalyptus.