Eucalyptus delegatensis subsp. tasmaniensis

Eucalyptus delegatensis subsp. tasmaniensis, synonym of E. risdonii var. elata is one of the tallest Australian trees, endemic to the mountain regions of Tasmania, where the largest known specimen reaches 87 metres (285 feet 5 inches). It stands out with its good cold resistance (down to - 12°C (53.6 °F)), and its ability to withstand harsh climate conditions and adapt to wet soils. This beautiful tree, with a majestic and balanced stature, soars on a very straight trunk, covered with fibrous and stringy bark, with an open and airy canopy and glaucous green foliage. The most beautiful specimens can reach 60 metres (196 feet 11 inches) high, which means choosing a suitable location in a large garden or park. It should be planted in an open space, in full sun, in acid or neutral, moist, well-drained soil, not too dry in summer.

Belonging to the Myrtaceae family, the Eucalyptus delegatensis subsp. tasmaniensis is a subspecies endemic to Tasmania, from all the alpine regions located between 500 and 1000 m (1640 ft 5 in and 3280 ft 10 in), outside the southwest. In these regions, with quite high rainfalls (sup. to 1200 mm/year), it grows on well-drained soils, made up of volcanic rocks and exposed to quite harsh climatic conditions (rain, wind, snow, frost). The denomination subsp. tasmaniensis refers to the state of Tasmania, the distribution area of this subspecies. In Australia, this species is an important source of timber.

This eucalyptus forms a tree, with an erect habit and a straight trunk, relatively devoid of branches. With rapid growth, in its natural habitat, it reaches a height of 40 to 60 m (131 ft 2 in to 196 ft 11 in) and 10 to 20 m (32 ft 10 in to 65 ft 7 in) in width. Under our climates it hardly exceeds 40 m (131 ft 2 in) in height. Unlike many Eucalyptus, this species does not have a lignotuber, a swelling of the collar at ground level (rich in starch) which allows the stump to restart in case of severe frost, fire or severe pruning. When young, it displays glaucous to reddish branches, bearing juvenile foliage, consisting of leaves, with short petioles, opposite, ovate, 3 to 7 cm (1.2 to 2.8 in) long and 2 to 6 cm (0.8 to 2.4 in) wide, pendulous, blue-green. Then, as it develops, the leaves are petiolate, alternate and take a lanceolate to crescent shape, 9 to 20 cm (3.5 to 7.9 in) long for 2 to 4 cm (0.8 to 1.6 in) wide, shiny, a pretty green. The leaves are leathery and slightly aromatic and give off a menthol fragrance when crushed, rich in eucalyptol. As it ages, the thick bark peels off in strips, revealing a smooth underlayer, cream to light grey or yellowish, or even green-yellow. Flowering occurs from January to March, on plants a few years old. The inflorescence, arranged in the leaf axil, is composed of 7 to 15 floral buds gathered in a tight bouquet and blooms into small flowers with numerous cream-white anthers, forming a pompom about 1 cm (0.4 in) in diameter. Rich in nectar, they are very attractive to bees. After flowering, the fruits, called "gumnuts", appear in the form of a woody, globular, truncate capsule, attached to the branch by a short petiole. Of a beautiful whitish-grey colour, they remain attached to the stem for a long time.

The Gum tree delegatensis subsp. tasmaniensis finds a place in a large garden, planted as a specimen in an open space to appreciate the beauty of its bark and the elegance of its foliage. In order to highlight its architectural habit, it is trained on a single trunk. It tolerates both semi-mountain and semi-arid climates in summer, and its resistance to cold will go down to -12°C (10.4 °F). Note that this Eucalyptus, native to the highlands and alpine regions of Australia, tolerates peaty and sandy soils well, even regularly waterlogged, but not swampy. It dislikes asphyxiating soils, too clayey or too chalky. It is therefore comfortable in wet soils, which it has the ability to dry out.