Eucalyptus mannifera subsp. mannifera

Brittle gum, Red spotted gum

Eucalyptus | Symphyomyrtus | Maidenaria | Triangulares | Microcarpae

Eucalyptus mannifera Mudie, Trans. Roy. Med.-Bot. Soc. London 1: 24 (1834) subsp. mannifera.

T: Bathurst, NSW, Jan. 1825, A.Cunningham 91: holo: K; iso: BM.

Eucalyptus mannifera subsp. maculosa (R.T.Baker) L.A.S.Johnson, Contr. New South Wales Natl Herb. 3: 107 (1962); E. gunnii var. maculosa (R.T.Baker) Maiden, Proc. Linn. Soc. New South Wales 26: 561, 562, 581 (1902); E. maculosa R.T.Baker, Proc. Linn. Soc. New South Wales 24: 598 (1900). T: Charleys Forest, Monga, NSW, Sept. 1898, W.Bäuerlen s.n.; lecto: NSW 54074, fide L.A.S.Johnson, loc. cit.

Tree to 20 m tall. Forming a lignotuber.
Bark smooth, powdery, white to cream, or at times yellow, pink, grey.
Juvenile growth (coppice or field seedlings to 50 cm): stem rounded in cross-section; juvenile leaves opposite for 4–6 pairs then alternate, sessile to shortly petiolate, linear to lanceolate or falcate, 4–10 cm long, 0.5–1.8 cm wide, green to blue-green or grey-green or subglaucous.
Adult leaves alternate, petiole 0.5–2.2 cm long; blade narrowly lanceolate to lanceolate to falcate, 7–18.5 cm long, 1–3 cm wide, base tapering to petiole, concolorous, dull, green to blue-green or grey-green, side-veins at an acute or wider angle to midrib, densely reticulate, intramarginal vein parallel to and remote from margin, oil glands mostly island.
Inflorescence axillary unbranched, peduncles 0.5–1 cm long, buds 7 per umbel, pedicels 0.1–0.5 cm long. Mature buds obovoid to ovoid, 0.4–0.6 cm long, 0.2–0.4 cm wide, green to yellow to red, scar present, operculum conical to rounded, stamens inflexed or irregularly flexed, anthers cuboid to oblong, versatile, dorsifixed, dehiscing by longitudinal slits (non-confluent), style long, stigma blunt, locules 3 or 4, the placentae each with 4 vertical ovule rows. Flowers white.
Fruit on pedicels 0.1–0.5 cm long, cup-shaped, hemispherical or obconical, 0.3–0.5 cm long, 0.4–0.7 cm wide, disc raised convex or oblique, valves 3 or 4, exserted.
Seeds brown, grey or black, 1–2.2 mm long, ovoid or flattened-ovoid, often pointed at one end, lacunose, dorsal surface smooth or shallowly pitted, hilum ventral.

Cultivated seedlings (measured at ca node 10): cotyledons more or less oblong; stems square or rounded in cross-section, smooth or slightly warty; leaves sessile or shortly petiolate, opposite for 4–12 nodes then becoming alternate, linear to lanceolate, 4–9.5 cm long, 0.3–2.3 cm wide, base tapering, margin entire, apex rounded or pointed, green to grey-green.

Flowering has been recorded in January, February, March, April, May and November.

Eucalyptus mannifera is a widespread, small to medium-sized tree species of the Central and Southern Tablelands of New South Wales extending into the hills and slopes of eastern Victoria.

E. mannifera has predominantly or completely smooth, white bark that is powdery to touch and is easily recognised among gum-barked species by the form, bark, dull bluish green to green leaves and seven-budded inflorescences and small fruit. In places it co-occurs with another unrelated, smooth-barked white gum, E. racemosa subsp. rossii (a scribbly gum). On occasions E. racemosa subsp. rossii lacks insect scribbles on the bark and in these circumstances the two species can be superficially similar. E. mannifera has pale yellow newly exposed bark while E. rossii has brilliant yellow to orange new bark. E. mannifera has an operculum scar on the buds, lacking in E. racemosa subsp. rossii and the operculum is usually pointed in E. mannifera, rounded in E. racemosa subsp. rossii. Leaf reticulation in E. mannifera is moderate to dense whilst very sparse in E. racemosa subsp. rossii.

There are three subspecies:

E. mannifera subsp. mannifera
The most widespread and has linear to lanceolate juvenile leaves. Subsp. mannifera occurs from around Bathurst in mid-western New South Wales south into Victoria, east from the Snowy River to Mt Buffalo, Mt Baranduda and Paradise Falls, always on dryish, often stony sites.

E. mannifera subsp. praecox
Has rounded to ovate juvenile leaves and occurs north of Bathurst in the Liverpool Range Capertee area of New South Wales on dry sandy sites.

E. mannifera subsp. gullickii
Has elliptical to broadly lanceolate juvenile leaves and occurs usually adjacent to swampy sites in eastern New South Wales from the Blue Mountains and Megalong Valley, south to Pigeon House area.

Eucalyptus mannifera 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. mannifera and three other species form series Microcarpae diagnosed by the smooth white bark, juvenile leaves that are shortly petiolate, non-swampy habitat, and small, rather flat-topped fruit. The other three species are E. scoparia (which differs in having glossy adult leaves), E. dorrigoensis (which has sessile stem-clasping ovate juvenile leaves) and E. elliptica (which has sessile large ovate-elliptic juvenile leaves).

Eucalyptus mannifera: Greek manna, gum and Latin -fera, bearing.