Red gums are widespread across most parts of Australia, from the deep fertile
soils of the wetter coastal areas, to the poorer soils and rocky terrain
on the tops of some the high mountains, to the drier sandy soils of the inland.
The most famous of all is the River red gum, Eucalyptus camaldulensis.
It can be found growing along most drainage channels and river banks throughout
the continent.
Red gums are usually fairly easy to recognise as agroup, often having smooth bark that
is mottled in shades of grey to white to cream to pink due to different
stages of weathering. Sometimes the bark develops
a dull granular texture similar to the related Grey gums. A few Red gum species have
rough bark (E.
morrisii, E. chloroclada, E.
terrica, E. exserta, E.
brassiana, E. lockyeri subsp. exuta, E.
rudis). The adult leaves
in most species are concolorous,
with moderate to dense reticulation and island oil glands.
The buds in
many species have opercula that
are relatively long and acute,
with ovule row
numbers 6 or 8, often with a gap to the placenta between
the inner rows. The fruit are
mostly with ascending discs
and prominently exserted valves and
the stems of seedlings or
young juveniles is normally square in cross-section.
The groups and species are
here arranged according to A New Classification of the genus Eucalyptus,
Brooker (2000). Some of the sub-series listed
here may be distinct enough to be recognised at a higher level (see notes
below). The groups and species are
diagnosed by the following:
Section Liberivalvae - bark smooth,
often granular in texture; leaf venation moderate
to dense, oil glands island (sometimes
sparse or absent); fruit with annular disc free
from ovary
roof; seed red-brown
to brown, cuboid to
obliquely pyramidal.
Eucalyptus seeana - adult leaves green, narrow lanceolate to lanceolate, normally narrower than 2 cm; buds not glaucous, operculum relatively long, 0.7–1.2 cm in length; juvenile leaves narrowly lanceolate.
Eucalyptus interstans - adult leaves green, lanceolate, normally narrower than 3 cm, buds not glaucous; operculum relatively long, 0.8–1.1 cm in length; juvenile leaves broadly lanceolate to ovate.–
Eucalyptus prava - normally a small poorly formed tree; newly exposed bark often red or orange; adult leaves blue-grey to glaucous, lanceolate to broadly lanceolate; buds usually glaucous, operculum relatively long, 0.7–1.1 cm in length; juvenile leaves ovate.
Eucalyptus bancroftii - often a small poorly formed tree; adult leaves broadly lanceolate, normally wider than 3 cm; buds not glaucous, operculum relatively long, 0.7–1.5 cm in length; juvenile leaves broadly lanceolate to ovate.–
Eucalyptus parramattensis subsp. parramattensis - adult leaves glossy green, lanceolate; buds not glaucous, operculum conical and relatively short, 0.3–0.7 cm in length; juvenile leaves lanceolate.
Eucalyptus parramattensis subsp. decadens - adult leaves glossy green, lanceolate, buds not glaucous; operculum conical, 0.6–0.8 cm in length; juvenile leaves lanceolate.
Eucalyptus parramattensis var. sphaerocalyx - adult leaves glossy green, lanceolate; buds not glaucous, operculum round and relatively short, 0.2–0.4 cm in length; juvenile lanceolate.
Section Exsertaria
- fruit with disc united
to the ovary
roof.
Series Erythroxylon -bark mostly
smooth (E. chloroclada & E.
terrica rough-barked); leaf venation moderate
to dense, oil glands island (sometimes
sparse or absent); stamens mostly
erect; seed cuboid to
obliquely pyramidal.
Eucalyptus tereticornis subsp. tereticornis - a well formed tree, normally smooth-barked (sometimes with accumulated rough slabs of bark at the base); buds and fruit not glaucous; operculum relatively long and narrow, 0.8–2.2 cm long (normally longer & narrower than E. tereticornis subsp. mediana); fruit 0.4–0.8 cm wide; seedling leaves ovate, 2.7–6.5 cm wide.
Eucalyptus tereticornis subsp. mediana - a well formed tree; normally smooth-barked (sometimes with accumulated rough slabs of bark at the base); buds and fruit not glaucous; operculum (0.5)0.6–1.2 cm long (normally shorter & broader than E. tereticornis subsp. tereticornis); fruit 0.6–1 cm wide; seedling leaves ovate, 3.5–8.5 cm wide.
Eucalyptus blakelyi - a well formed tree; normally smooth-barked (sometimes with accumulated rough bark at the base); buds and fruit glaucous and non-glaucous; operculum relatively long & narrow, 0.5–1.1 cm long (normally slightly shorter than in E. tereticornis subsp. tereticornis); fruit 0.4–0.8 cm wide; seedling leaves orbicular to ovate to elliptical, 2.5–7 cm wide.
Eucalyptus kabiana - a mallee or rarely a small tree; normally smooth-barked; buds and fruit not glaucous; operculum relatively long and narrow, 0.7–0.9 cm long; fruit 0.5–0.7 cm wide; juvenile leaves lanceolate, 2–3 cm wide.
Eucalyptus glaucina - a well formed tree; normally smooth-barked; buds glaucous, operculum 0.5–1 cm long; fruit 0.6–1 cm wide; seedling leaves orbicular to ovate, 4.5–8 cm wide.
Eucalyptus amplifolia subsp. amplifolia - a well formed tree; normally smooth-barked; buds and fruit not glaucous, pedicellate; operculum 0.5–0.9 cm long; fruit 0.4–0.6 cm wide; seedling leaves glossy green, deltoid to orbicular to ovate, held for many nodes in a horizontal plane, 5–8(10) cm wide (juvenile leaves in the field to 18 cm wide).
Eucalyptus amplifolia subsp. sessiliflora - a well formed tree; normally smooth-barked; buds and fruit not glaucous, sessile; operculum 0.6–0.9 cm long; fruit 0.5–0.6 cm wide; seedling leaves glossy green, deltoid to orbicular to ovate, held for many nodes in a horizontal plane, 4–8(10) cm wide.–
Eucalyptus nandewarica - poorly formed tree or mallee; usually smooth-barked; buds and fruit small, not glaucous; operculum 0.5–0.6 cm long; fruit 0.5(0.6) cm wide; seedling leaves broadly lanceolate, 3–5 cm wide.
Eucalyptus dwyeri - small tree or rarely a mallee; usually smooth-barked; buds and fruit small (slightly larger than E. nandewarica), not glaucous; operculum 0.5–0.8 cm long; fruit (0.5)0.6–0.8 cm wide; seedling leaves lanceolate, 1–2.6 cm wide.
Eucalyptus dealbata - small tree; usually smooth-barked; buds and fruit normally distinctly glaucous; operculum 0.4–0.8 cm long; fruit 0.5–0.7 cm wide; seedling leaves orbicular to ovate, 3.3–6.5 cm wide.
Eucalyptus vicina - small tree or mallee; usually smooth-barked; buds and fruit not glaucous; operculum 0.4–0.7 cm long; fruit 0.4–0.8 cm wide; seedling leaves ovate, 2.5–5 cm wide.
–
Eucalyptus flindersii - mallee or rarely a small tree; usually smooth-barked; buds and fruit not glaucous; operculum (0.4)0.5–0.7 cm long, umbels normally 3-flowered; fruit 0.4–1 cm wide; seedling leaves ovate to deltoid 3.5–8 cm wide.
Eucalyptus gillenii - mallee; smooth-barked; buds and fruit not glaucous; operculum 0.5–0.9(1.2) cm long; umbels normally 7-flowered; fruit 0.6–1.2 cm wide; juvenile leaves lanceolate to broadly lanceolate, (0.8)1.5–3(3.5) cm wide.Eucalyptus nudicaulis - mallee; smooth-barked; buds and fruit not glaucous; operculum 0.7-1 cm long; umbels normally 7-flowered; fruit 0.6-1 cm wide; juvenile leaves narrowly lanceolate, 0.8-2 cm wide.
–
Eucalyptus infera - mallee; smooth-barked; buds and fruit not glaucous; operculum 0.8–1.1 cm long; fruit 0.4–0.8 cm wide; seedling leaves ovate, 4–7 cm wide, often with shallow crenulations on the margins.
–
Eucalyptus chloroclada - tree; normally with thin, rough, orange-brown to brown, fibrous bark over part or all of the trunk, sometimes smooth-barked in parts of south-east Queensland; buds and fruit not glaucous; operculum 0.5–0.9 cm long; fruit with a flattish disc; seedling leaves ovate, 2–5 cm wide.
Eucalyptus terrica - tree; normally with thin, rough, orange-brown to brown, fibrous bark over part or all of the trunk; buds and fruit not glaucous; operculum 0.4–0.6 cm long; seedling leaves normally lanceolate, 1–3.8 cm wide.
Series Rostratae - bark smooth; leaf venation moderate to dense, oil glands island (sometimes sparse or absent);stamens erect or variously inflexed; seed cuboid to pyramidal, yellow to yellow-brown with double seed coat.
Eucalyptus camaldulensis var. camaldulensis - tree; normally smooth-barked (sometimes with accumulated rough bark at base); operculum beaked; seedling leaves ovate to lanceolate.
Eucalyptus camaldulensis var. obtusa - tree; normally smooth-barked; operculum obtusely conical to rounded; seedling leaves ovate to lanceolate.
Eucalyptus camaldulensis subsp. simulata - tree; smooth-barked; operculum acute, very long and narrow; seedling leaves ovate to lanceolate.
Series Singulares - bark commonly
rough; leaf venation moderate
to dense, oil glands island; stamens irregularly inflexed; seed cuboid to
obliquely pyramidal,
mostly brown with a single seed coat
(sometimes yellow or straw coloured with a double seed coat).
Eucalyptus rudis subsp. cratyantha - tree; normally rough-barked (rarely smooth-barked); fruit 1.1–1.4 cm wide; seedling leaves ovate to deltoid, 4.5–8.5 cm wide.
Eucalyptus rudis subsp. rudis - tree; normally rough-barked (rarely smooth-barked); fruit 0.7–1 cm wide; seedling leaves ovate to deltoid, 4.5–8.5 cm wide.
Series Phaeoxylon - bark rough;
leaf venation mostly
moderate, oil glands island; stamens mostly
erect; seed cuboid to
obliquely pyramidal,
brown to black with single seed coat.
Eucalyptus brassiana - tree; trunk wholly or partly rough-barked, larger branches smooth-barked; adult leaves green; umbels 7-flowered; fruit relatively large, 0.7–1.2 cm wide with a steeply ascending disc; juvenile leaves ovate to lanceolate, (3)4–7 cm wide.
Eucalyptus lockyeri subsp. lockyeri - small tree; normally rough-barked over entire trunk, large branches smooth-barked; adult leaves normally glaucous to blue-grey; umbels 7-flowered, buds glaucous; fruit 0.6–1(1.2) cm wide; juvenile leaves ovate to lanceolate, 3.5–5.5 cm wide.
Eucalyptus lockyeri subsp. exuta - small tree; partly rough-barked, upper trunk and large branches smooth-barked; adult leaves green; umbels 7-flowered; fruit 0.6–0.8 cm wide with a ± flat disc; juvenile leaves lanceolate, 0.9–1.3(1.6) cm wide.
Eucalyptus ammophila - mallee; normally rough-barked to the base of the branches; adult leaves green to grey-green; umbels 7(11)-flowered; fruit 0.6–0.9 cm wide; juvenile leaves ovate to lanceolate, 2.2–3.6 cm wide.
Eucalyptus exserta - tree or mallee; normally rough-barked to the small branches; adult leaves green to grey-green; umbels 7-flowered; fruit 0.4–0.8 cm wide; juvenile leaves linear to narrow lanceolate, 0.3–1.3 cm wide.
Eucalyptus morrisii - tree or mallee; rough-barked to the small branches on larger trees, lesser amount of rough bark on smaller individuals with the branches sometimes smooth-barked; adult leaves grey-green; umbels commonly 3-flowered (rarely 7-flowered); fruit 0.7–1.1 cm wide; juvenile leaves linear to narrow lanceolate 0.5–1.2 cm wide.
Series Connexentes - Bark smooth;
leaf venation dense,
oil glands island & intersectional; stamens inflexed; fruit with
an annular disc; seed flattened ovoid to
obliquely pyramidal,
toothed (because the fruit have
an annular disc and
the bark is
often granular in texture, this group maybe better placed in Section Liberivalvae or
a new Section).
Eucalyptus hallii - tree; smooth bark often granular in texture; adult leaf width 2–3.5 cm; umbel peduncle 0.3–1 cm long; fruit obconical, 0.6–0.8 cm wide.
Eucalyptus broviniensis - tree; smooth bark often granular in texture; adult leaf width 2.5–4.5 cm wide; umbel peduncle 0.8–2.2 cm long; fruit obconical, 0.7–1 cm wide.
Series Subexsertae - Bark smooth;
leaf venation dense
to very dense, oil glands intersectional or
absent; fruit with
an annular disc.
Sub-series Applanatae -
smooth bark often powdery and
not granular in texture; seed flattened, ± ovoid in
shape, toothed; buds round
in shape (because the fruit have
an annular disc and
the seed are
flattened ovoid with ± ventral hilum,
this group may be better placed in a new Section).
Eucalyptus alba var. australasica - tree; mature crown leaves petiolate, concolorous, lanceolate to rarely ovate; buds pedicellate; fruit 0.5–0.8 cm wide; juvenile leaves ovate.
Eucalyptus bigalerita - tree; mature crown leaves petiolate, concolorous, orbicular to deltoid to cordate; buds sessile to shortly pedicellate; fruit 0.8–1.2 cm wide; juvenile leaves deltoid to cordate.
Eucalyptus platyphylla - tree; mature crown leaves petiolate, concolorous, orbicular to deltoid to cordate (rarely ovate to broadly lanceolate); buds sessile to shortly pedicellate; fruit 0.6–1 cm wide; juvenile leaves deltoid to cordate.
Eucalyptus tintinnans - tree; mature crown leaves petiolate, concolorous, orbicular to deltoid (rarely cordate to ovate); buds sessile to shortly pedicellate; fruit 0.5–0.6 cm wide.
Eucalyptus apodophylla - small tree; mature crown leaves normally sessile (rarely shortly petiolate), discolorous (rarely concolorous), elliptical, ovate to broadly lanceolate; buds sessile to shortly pedicellate; fruit 0.4–0.6(0.8) cm wide; juvenile leaves glaucous, ovate to elliptical.
Eucalyptus houseana - tree; mature crown leaves petiolate, concolorous, lanceolate to falcate; buds sessile to shortly pedicellate; fruit 0.4–0.5(0.6) cm wide; juvenile leaves ovate to elliptical.
Sub-series Pyramidales - seed obliquely pyramidal in
shape, toothed; buds ovoid to obovoid in
shape (because the fruit have
an annular disc and
the seed are
obliquely pyramidal with
a ± terminal hilum,
this group may be better placed in a new Section).
Eucalyptus mooreana - small tree or mallee; mature crown leaves opposite, sessile, elliptical to ovate to orbicular to cordate (rarely lanceolate), dull green to grey-green to glaucous; umbels 7-flowered, buds sessile to shortly pedicellate, glaucous; fruit 0.6–0.9 cm wide; juvenile leaves orbicular to ovate to elliptical to cordate.
Eucalyptus pantoleuca - small tree; mature crown leaves opposite, petiolate, ovate to orbicular to deltoid, dull and glaucous; umbels 3-flowered, sessile to shortly pedicellate, glaucous; fruit 1.5–2.4 cm wide; juvenile leaves orbicular to deltoid.
Eucalyptus herbertiana - small tree or mallee; mature crown leaves alternate, lanceolate to falcate, dull green to grey-green; umbels normally 7-flowered(rarely 3-flowered), buds sessile to shortly pedicellate; fruit 0.4–0.6 cm wide; juvenile leaves ovate.
Eucalyptus cupularis - small tree; mature crown leaves alternate, lanceolate to falcate, dull green to grey-green; umbels 7-flowered, buds normally sessile, glaucous; fruit 0.7–1.2 cm wide; juvenile leaves ovate.
Eucalyptus glomericassis - small tree; mature crown leaves alternate, lanceolate to falcate, glossy green; umbels 7-flowered, buds normally pedicellate; fruit 0.6–0.9 cm wide; juvenile leaves ovate.
Eucalyptus gregoriensis - small tree or mallee; mature crown leaves alternate, narrowly lanceolate to lanceolate to falcate, dull green to grey-green to glaucous; umbels normally 3-flowered(rarely 7-flowered), buds sessile; fruit 0.5–0.6 cm wide; juvenile leaves ovate to lanceolate.
Section Platysperma - Bark smooth;
leaf venation very
dense, oil glands usually
absent; seed flattened, ovoid in
shape, not toothed.
Eucalyptus rupestris - small tree; adult leaves elliptical to ovate to broadly lanceolate, dull green; fruit (0.2)0.3–0.4 cm wide, disc narrow, descending, valves near the rim of the fruit or slightly exserted.
Eucalyptus kenneallyi - small tree; adult leaves narrowly lanceolate, dull green to grey-green; fruit 0.3–0.35 cm wide, disc narrow, descending, valves enclosed.
Eucalyptus umbrawarrensis - tree; adult leaves narrowly lanceolate, glossy green; fruit 0.3–0.4 cm wide, disc narrow, descending, valves near the rim of the fruit or slightly exserted.
Eucalyptus leucophloia subsp. euroa - small tree or mallee; adult leaves lanceolate to ovate, dull green to grey-green to blue-grey to glaucous; fruit 0.4–0.6 cm wide, disc narrow, descending, valves prominently exserted.
Eucalyptus leucophloia subsp. leucophloia - small tree; adult leaves lanceolate to ovate, dull green to grey-green to blue-grey to glaucous; fruit 0.4–0.6 cm wide, disc narrow, descending, valves enclosed or near the rim.
Eucalyptus confluens - tree; adult leaves lanceolate to rarely falcate, glossy green; fruit 0.6–0.7 cm wide, disc broad, level to slightly ascending, valves slightly exserted or near the rim.
Eucalyptus brevifolia - tree or rarely mallee; adult leaves lanceolate to broadly lanceolate to ovate, dull blue-grey to glaucous; fruit 0.6–0.9 cm wide; disc broad, level to slightly ascending, valves slightly exserted or near the rim.
Eucalyptus ordiana - tree or mallee; adult leaves broadly lanceolate to 8 cm wide, dull grey-green to glaucous; fruit 0.5–0.7 cm wide, disc ascending, valves at rim level or slightly exserted.