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Eucalyptus accedens W.Fitzg., J. W. Austral. Nat. Hist.
Soc. 1: 21 (1904).
T: near Pingelly, W.A., Nov. 1903, W.V.Fitzgerald s.n.:
holo: NSW; iso: E, PERTH.
Trees to 25 m tall. Forming a lignotuber.
Bark smooth throughout, powdery, white over pale orange
to creamy pink.
Branchlets with glandular pith.
Juvenile growth (coppice or field seedlings to 50 cm)
stems squared in cross-section, often glaucous; juvenile leaves
always petiolate, alternate, deltoid, 4-17 cm long, 3-11 cm wide,
base truncate or sometimes lobed, margin entire or subcrenulate,
apex rounded to broadly pointed, glaucous at first maturing blue-green.
Adult leaves alternate, petiole 1.3-3.2 cm long; blade
usually lanceolate, 8-18 cm long, 1.2-3 cm wide, base tapering
to petiole or rounded, margin entire, apex pointed, concolorous,
dull, blue-green (non-glaucous), side-veins
greater than 45° to midrib, densely to very densely
reticulate, intramarginal vein remote from margin, oil glands
intersectional.
Inflorescences axillary, single, peduncle 0.7-1.7 cm long;
buds 7, 9 or 11,pedicellate, cylindrical to obovoid or ovoid,
scar present, operculum bluntly conical to rounded, rarely apiculate,
stamens inflexed, anthers oblong, versatile, dorsifixed, dehiscing
by longitudinal slits (non-confluent), style straight, long, stigma
blunt, locules (3)4, the placentae each with 4 vertical ovule
rows; flowers cream to yellowy cream.
Fruit pedicellate, usually cylindrical to barrel-shaped,
(0.5)0.6-0.9 cm wide, disc descending vertically, valves (3)4,
rim level or slightly exserted.
Seed brown, 1.5-2.5 mm long, ovoid or flattened-ovoid,
scarcely reticulate, hilum ventral.
Cultivated seedling (measured at node 10): cotyledons Y-shaped
(bisected); stems square in cross-section, glaucous; leaves always
petiolate, opposite for 3 to 5 nodes then alternate, cordate to
deltoid or broadly ovate, 3-6.5 cm long, 3-6.5 cm wide, sometimes
longer than wide, glaucous.
NOTES
Eucalyptus accedens (Latin accedens, approaching
or resembling, referring to the similarity of the species to E.
wandoo ).
A small to medium-sized tree endemic to Western Australia, found
in the Darling Range from about Williams in the south, northwards
to south-east of Geraldton, particularly on lateritic breakaways
or stony ridges, usually above stands of E.
wandoo . E. accedens has white to pink, powdery
smooth bark, juvenile leaves which are petiolate, strikingly large
(to 11 cm wide), deltoid and glaucous, and dull, blue-grey to
blue-green adult leaves.
Eucalyptus accedens belongs to Eucalyptus subgenus
Symphyomyrtus section Bisectae subsection Glandulosae
because the cotyledons are bisected, buds have an operculum scar
and the branchlets have oil glands in the pith. Within this subsection
E. accedens belongs to a small subgroup of eight species,
series Accedentes, further characterized by having buds
with inflexed stamens, ovules in 4 rows and juvenile leaves petiolate.
The species are E. accedens, E. laeliae
, E. leprophloia , E. trivalvis
, E. pruiniramis , E.
zopherophloia , E. prominens and, outside
the scope of this edition of EUCLID, E. pilbarensis.
E. accedens is closely related to E.
laeliae which occurs within the broad distribution of
E. accedens but is restricted to the western scarp of the
Darling Range east and south-east of Perth. E.
laeliae differs by having lanceolate juvenile leaves,
white or yellow bark in season and smaller buds and fruit. E.
accedens is also related to two mallees of restricted occurrence
in the northern part of its distribution, E.
zopherophloia , south of Dongara, and E.
leprophloia , north of Badgingarra, which have rough bark
and green, slightly to distinctly glossy adult leaves and do not
occur on breakaways. A third related species, E.
pruiniramis , a partly rough-barked tree or smooth-barked
mallee, differs in having glaucous branchlets, slightly larger
fruit and smaller more ovate juvenile leaves. E.
pruiniramis occurs on gravelly soils in the Watheroo
to Three Springs area.
E. accedens is easily distinguished from other smooth-barked
trees in its natural range by its powdery bark that seasonally
turns from white to orange and by the juvenile growth which is
usually present in a stand. It is most likely to be confused with
the superficially similar E.
wandoo subsp. wandoo which has non-powdery bark
and conspicuously fusiform buds (ovoid in E. accedens)
with some erect stamens in bud (stamens completely inflexed in
E. accedens), smaller juvenile leaves, and occupies nearby
sites lower in the landscape.
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