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Eucalyptus angustissima F.Muell. Fragm. 4: 25 (1863)
subsp. angustissima.
T: between Point Malcolm and Point Dover, W.A., G.Maxwell
s.n.; holo: MEL; iso: K, NSW.
Mallee to 5 m tall, rarely to 8m. Forming a lignotuber.
Bark smooth throughout, mottled pale grey, pale brown, orange
and whitish, ribbons sometimes present.
Branchlets lacking oil glands in the pith.
Juvenile growth (coppice or field seedlings to 50 cm): stems
rounded in cross-section; juvenile leaves sessile to shortly petiolate,
alternate, 4.5-8 cm long, 0.3-0.4 cm wide, lower leaves dull, bluish
green, upper leaves green and glossy.
Adult leaves erect, alternate, sessile or with petioles to
0.2 cm long; blade
linear, (5.5)7-11.5 cm long, 0.15-0.3(0.4) cm wide, base tapering
to petiole, margin entire, apex pointed and sometimes uncinate, concolorous,
dull or glossy, green, midrib the only prominent vein (dried leaves
appear channelled), side veins and reticulation obscure, oil glands
intersectional or obscure.
Inflorescences axillary, single, peduncles 0.2-0.4 cm long;
buds 7, pedicellate, ovoid (egg-in-eggcup) with hypanthium widest
below the join with operculum, scar present, operculum rounded to
conical, stamens inflexed, anthers oblong to reniform, versatile,
dorsifixed, dehiscing by short lateral slits, style long, straight,
stigma more or less blunt, locules 3, the placentae each with 4 vertical
rows of ovules; flowers creamy white.
Fruit pedicellate, broadly and shallowly cupular to hemispherical
or flattened-globose and swollen below rim, 0.5-0.8 cm wide, disc
level, valves 3, at rim level.
Seed tan, 1.0-2.5 mm long, flattened-ovoid, dorsal surface
+/- smooth, at times slightly furrowed, hilum ventral.
Cultivated seedling (measured at ca node 10): cotyledons Y-shaped
(bisected); stem rounded in cross-section,
smooth or slightly warty; leaves more or less sessile, the lower nodes
sometimes crowded, opposite for 5 to 7 nodes then alternate, linear,
+/- thickened and incurved, 6.5-9.5 cm long, 0.2-0.4 cm wide, green,
margin may be entire or irregular.
NOTES
Eucalyptus angustissima (Latin, the superlative of angustus,
narrow, referring to the leaves).
A mallee endemic to Western Australia. The species occurs in southern
coastal and subcoastal areas from Lake Chinocup and north-west of
Ravensthorpe eastwards to Esperance and Israelite Bay. The bark is
smooth and the crown of erect, dull to glossy, green leaves. The species
is notable for the narrowest adult leaves of all eucalypts.
Eucalyptus angustissima belongs in Eucalyptus subgenus
Symphyomyrtus section Bisectae sub-section Destitutae
because buds have two opercula, cotyledons are Y-shaped and branchlets
lack oil glands in the pith. Within this sub-section E. angustissima
is closely related to only two other species, viz. E. foliosa
and E. misella , together forming series Angustissimae,
characterized by the erect leaves, egg-in-eggcup buds and stamens
with more or less reniform anthers. The habitat of both subspecies
of E. angustissima is similar to that of E. foliosa
being white sands in the vicinity of salt lakes, whilst E. misella
occurs away from salt lakes on sand with gravel high in the profile.
E. angustissima differs from E. misella and E. foliosa
in having leaves always less than 0.8 cm wide, buds only in umbels
of 7s (7, 9 and 11 in the other two species).
There are two subspecies of E. angustissima:
subsp. angustissima,
leaves less than 0.4 cm wide; found sporadically from north of Esperance
to Israelite Bay.
subsp. quaerenda,
leaves 0.4-0.7 cm wide; found at Lake Chinocup and between Ravensthorpe
and Lake King.
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