Eucalyptus viminalis subsp. hentyensis

Western Tasmania Sand Gum

Eucalyptus | Symphyomyrtus | Maidenaria | Euryotae | Viminales | Lanceolatae

Eucalyptus viminalis subsp. hentyensis Brooker & Slee, J. Adel. Bot. Gardens 6: (in press, 2006).

T: Tasmania: S of Henty River, between Zeehan and Strahan, 42°2'16"S, 145°16'13"E, 19 Jan. 1996, M.I.H.Brooker 12467 & A.V.Slee; holo: CANB; iso: HO, MEL, NSW.

Tree to 6 m tall. Forming a lignotuber.
Bark smooth except for some imperfectly decorticated rough grey bark for 1 m at base of trunk; smooth bark grey to cream with pink patches.
Juvenile stem rounded or square in cross-section, warty or smooth; juvenile leaves opposite for many pairs, sessile, ovate to broadly lanceolate to elliptical, 2.8–6 cm long, 1.7–2.8 cm wide, bases stem-clasping to rounded, margin entire or crenulate, green, thick; note that pot-grown seedlings have unremarkably lanceolate and thin leaves (like typical E. viminalis) compared with the very broad, leathery, leaves of field coppice up to 2 m tall.
Adult leaves alternate, petiole 0.9–2.2 cm long; blade lanceolate, 7–15 cm long, 1.2–3 cm wide, flat or slightly undulate, base tapering to petiole, margin entire, concolorous, glossy, green, side-veins greater than 45° to midrib, moderately to densely reticulate, intramarginal vein parallel to and remote from margin, oil glands island and intersectional.
Inflorescence axillary unbranched, peduncles 0.3–1 cm long, buds 3 or 7 per umbel, on pedicels to 0.2 cm long or sessile. Mature buds oblong to ovoid to obovoid, 0.5–0.7 cm long, 0.3–0.5 cm wide, green, scar present, operculum conical, stamens irregularly flexed, anthers cuboid or cuneate, 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 sessile or on pedicels to 0.2 cm long, cup-shaped or cylindrical, 0.3–0.7 cm long, 0.5–0.8 cm wide, disc raised-convex to annular, valves 3 or 4, near rim level.
Seeds blackish or brown, 2–3 mm long, ovoid or flattened-ovoid, often pointed at one end, usually lacunose, dorsal surface shallowly pitted, hilum ventral.

Cultivated seedlings (measured at ca node 10): cotyledons bilobed; stems rounded or square in cross-section, slightly warty; leaves sessile, opposite for many pairs, lanceolate, 4.8–7.2 cm long, 1.7–2.6 cm wide, base amplexicaul, truncate or rounded, margin entire, apex pointed, dull, more or less concolorous, green.

Specimens examined: Tasmania: S of Henty River, between Zeehan and Strahan, 19 Jan. 1996, M.I.H.Brooker 12468, 12469, 12470 & A.V.Slee (CANB); Henty sand dunes picnic area, 20 km N of Strahan, 5 Sep. 1979, A.M.Gray 417, 418, 419 (CANB, HO); West Coast: Henty Road at the Henty River Bridge c. 18 km south of Zeehan, 24 May 1985, A.M.Gray 660 (CANB); Henty road, c. 1 km south of the Henty river bridge, 24 May 1985, A.M.Gray 662 (CANB, HO).

Flowering has been recorded in February.

Eucalyptus viminalis is a species of small to very tall tree, widespread in well-watered parts of south-eastern Australia from southern Eyre Peninsula and Kangaroo Island of South Australia through Victoria, Tasmania and eastern New South Wales as far north as the tablelands between Inverell and Deepwater extending east to the escarpment. It is recognised most easily by the many pairs of opposite, sessile, lanceolate, green juvenile leaves. The crown is usually ribbony and the bark is mostly smooth in mountain forms although many populations elsewhere have a black butt or rough bark over most of the trunk. It is related to E. rubida and E. dalrympleana, both of which have rounded, not narrowly lanceolate juvenile leaves. Another seven-budded form, occurring on the Northern Tablelands of New South Wales and its eastern escarpment, has been described recently as E. nobilis (q.v.).

There are four subspecies:

E. viminalis subsp. viminalis
Occurs mostly in wetter or seasonally well-watered areas in New South Wales, Victoria, Tasmania, Bass Strait islands and South Australia, particularly in mountain valleys but also on alluvium along streams on tablelands areas. Subsp. viminalis can be very tall (to 90 m in Tasmania) and is generally smooth-barked and three-budded. In South Australia it occurs only in the central part of the Mt Lofty Ranges.

E. viminalis subsp. cygnetensis
Has rough bark usually to the larger limbs and "umbels of seven buds, infrequently less, to as few as three" (Boomsma, 1980, p. 295). Subsp. cygnetensis occurs from the Grampians in Victoria, south-west to Mt Gambier in South Australia, on Kangaroo Island, in the Port Lincoln area, and in the Mt Lofty Ranges where the rough-barked plants occur with mixtures of umbels in threes and sevens. Plants with 3s and 7s also occur in the Grampians.

E. viminalis subsp. hentyensis
Endemic to Tasmania where it grows on poor white sands on the west coast, north from Strahan. Subsp. hentyensis has little rough bark, coarse, broad juvenile leaves and buds in threes or sevens.

E. viminalis subsp. pryoriana
Subsp. pryoriana is endemic to Victoria and is a small tree of infertile coastal sands from south of Geelong to east of Marlo in Gippsland. It has rough bark over most of the trunk and buds in threes.

In 2011 Rule (see Muelleria 29(1) 5-7) described a new subspecies, Eucalyptus viminalis subsp. siliceana from Wail State Forest on the edge of the Wimmera region of Victoria. This subspecies has buds in umbels of 3s and 7s, buds with a rounded operculum, fruit within the size range of all other subspecies, and field juveniles with leaves narrowly lanceolate, opposite on the stem for many pairs but green to subglaucous with new growth tips glaucous. It occurs on siliceous sands. It is not (yet) included in EUCLID key.

Eucalyptus viminalis 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. viminalis belongs in series Viminales subseries Lanceolatae, having buds in threes or sevens, fruit with an ascending disc and exserted valves, and green, sessile, lanceolate juvenile leaves opposite for many pairs.

Eucalyptus viminalis: Latin viminalis, bearing shoots or ribbons for wicker-work, presumably referring to the prominent ribboning of the bark.

subsp. hentyensis: referring to the Henty River, Tasmania, near the locality of occurrence.