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Eucalyptus angustissima subsp. quaerenda L.A.S.Johnson
& K.D.Hill, Telopea 4: 598 (1992).
T: Western Australia: 100 metres S of south shore of Lake Chinocup,
13 Nov 1986, K.D.Hill 2460, L.A.S.Johnson & D.F.Blaxell; holo:
NSW; iso CANB, MEL, PERTH.
Mallee to 4 m tall, often rounded, with foliage to ground.
Forming a lignotuber.
Bark smooth throughout, mottled pale grey, pale brown, pinkish-grey
and whitish, ribbons sometimes present on lower trunks.
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, 0.3-0.6 cm wide, lower leaves
dull, bluish green, upper leaves green and glossy.
Adult leaves erect, alternate, petioles 0.2-0.5 cm long;
blade linear, 5.5-9 cm long, 0.4-0.7
cm wide, base tapering to petiole, margin entire, apex finely pointed
and sometimes uncinate, concolorous, dull and bluish green at first
soon maturing glossy, green, side-veins
greater than 45° to midrib
or obscure, reticulation moderate to dense or obscure, oil glands
intersectional, +/- round.
Inflorescences axillary, single, peduncles 0.1-0.6 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 or +/- sessile, broadly and shallowly cupular
to obconical or flattened-globose and often swollen below rim, 0.5-0.7(0.8)
cm wide, disc usually level, sometimes obliquely descending, 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 to slightly warty; leaves usually sessile, the lower nodes
sometimes crowded, opposite for ca 6 nodes then alternate, linear,
thickened and slightly incurved, 4.5-9 cm long, 0.2-0.5 cm wide, green
to grey-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 (from Latin, quaerendus, to be sought,
alluding to early searches for these plants),
leaves 0.4-0.7 cm wide; found at Lake Chinocup and between Ravensthorpe
and Lake King.
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