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Eucalyptus (From eu well and kalypto)

(from eu, well, and kalypto, to cover as with a lid; limb of the calyx covering the flower before expansion, and afterwards falling off in one piece, in the shape of a lid or cover). Gum-tree. Including Eudesmia. ORD. Myrtaceae. A genus of 140 or more species of tall evergreen greenhouse trees, with very few exceptions natives of Australia, where they constitute a large portion of the forest vegetation. Peduncles axillary, one-flowered, or bearing an umbel of from three to fifteen flowers. Leaves quite entire, coriaceous, usually alternate, very variable, even in the same tree, quite glabrous except in a very few of the species. It is worthy of remark that the Gum Trees, though among the largest trees in the world, have very small, or even minute, seeds. In their native country, the Eucalypti form extensive forests, and grow very fast, some of them reaching an immense height and having trunks in the same proportion. The timber is extremely durable, and is largely used by colonial ship-builders, implement-makers, engineers, &c. None of the species attain a size sufficiently large for use as timber in this country, as they are not hardy enough to withstand a severe winter outside. Several succeed on a south wall with protection in winter, and all are useful decorative greenhouse plants. They are called Gum Trees in consequence of the quantity of gum that exudes from their trunks. E. globulus, the Blue Gum, one of the most valuable timber trees of the Southern hemisphere, is also largely cultivated in many parts of the world, especially in the Mediterranean region and in malarious districts in Italy. Further, it is the species grown more than others in this country for its value in sub-tropical gardening, the leaves being of a distinct glaucous hue, and quite different from those of any other plant similarly employed. Eucalypti are best raised from imported seeds, which generally vegetate freely. They should be sown thinly in pots or pans of light sandy soil, and placed in a little heat. E. globulus, when intended to be used for sub-tropical bedding or for a group on a lawn, is best sown in August and grown on through the winter for use the following season. By this method, much larger and better plants may be obtained than when sowing is deferred till spring. It is best to raise new plants each year, as lifted ones do not regain their beauty of the preceding season, and they cannot be depended on to stand outside, at least, not in many places. Being fast growing plants, considerable space must be allowed when they become established, either in the open ground or in pots. A rather rich soil, composed of loam and decayed manure, with the addition of some charcoal, to keep it open, is most suitable. E. citriodora is very useful for growing in small pots for the conservatory, its scented leaves rendering it a general favourite. Comparatively few of the species are grown in this country.

E. amygdalina (almond-leaved). fl., peduncles axillary or lateral, nearly terete, with four to eight flowers. l. alternate, linear-lanceolate, 3in. long, three lines broad, attenuated at the base. 1820. A moderate sized or large tree. (B. M. 3260.) In the Museum, No. 1, at Kew, there is a photograph of the base of a tree from Victoria, known as "Big Ben." The tree measured 56ft. in circumference, at base, and was 400ft. high. This species forms the highest of all known trees; one is recorded measuring 470ft. high, far exceeding even the well-known Giant-trees of California (Sequoia gigantea). E. calophylla (beautiful-leaved). fl. rather large, in a terminal corymbose panicle, with one or two sometimes in the upper axils; umbels loose; peduncles flattened, or nearly terete; pedicels longer than the calyx tube. l. ovate, ovate-lanceolate, or lanceolate, obtuse or mucronate, acute, rather rigid, with numerous transverse parallel veins, the intramarginal one scarcely distant from the edge. A very beautiful tree. (B. M. 4036, under name of E. splachnicarpa.) E. citriodora (lemon-scented).* l. oblong-lanceolate, covered with glandular hairs, which, when gently rubbed, emit a powerful odour, resembling that of the lemon-scented Aloysia. Australia. An interesting greenhouse plant. E. coccifera (Coccus-bearing).* fl. purple; peduncles axillary or lateral, terete, or slightly compressed, bearing each an umbel of four to eight flowers. December. l. in the usual form mostly ovate-lanceolate, falcate and very oblique at the base, more or less acuminate, 4in. to 6in. long, thick with very oblique distant anastomosing veins, the intra-marginal one at some distance from the edge. A small, generally very glaucous, tree. SYN. E. daphnoides. (B. M. 4637.) There is a variety, parviflora, having smaller flowers, and extremely short peduncles.

E. cordata (heart-shaped). A synonym of E. pulverulenta. E. cornuta (horned). fl. red, yellow; peduncles axillary, terete or slightly compressed, each bearing six to twelve, or even more flowers, sessile, but not immersed in the receptacle. l. lanceolate or ovate-lanceolate, mostly under 4in. long, rather thick; the veins irregularly oblique, the intramarginal one at a distance from the edge. A tall shrub or small tree, with a smooth bark. (B. M. 6140.) E. daphnoides (Daphne-like). A synonym of E. coccifera. E. gigantea (gigantic). A synonym of E. obliqua.

E. globulus (globuled).* Blue Gum-tree. fl. large, axillary, solitary, or two or three together, closely sessile on the stem, or on a peduncle not longer than thick. l., of the young tree opposite, sessile, and cordate; of the full grown tree, lanceolate or ovate-lanceolate, nearly falcate, 6in. to 12in. long. h. sometimes exceeding 300ft. 1810. The leaves of this and other species have been supposed to possess febrifugal properties. Smoked in the form of cigars, they have been recommended in asthma. The oil obtained from the leaves is antiseptic.

E. Gunnii (Gunn's).* Cider-tree of Tasmania. fl. white; peduncles axillary, very short, each with three rather large almost sessile flowers. l. ovate-lanceolate or elliptical and obtuse to lanceolateacute. A bush or small tree, sometimes attaining a height of 30ft. Perhaps the hardiest of all the species.

E. macrocarpa (large-fruited). fl. very large, solitary, on very short, thick, axillary peduncles. June. l. opposite, sessile, broadly cordate-ovate, acute or obtuse, often 6in. long, or even more, very thick and rigid. h. 6ft. to 10ft. 1842. A stout shrub, usually more or less mealy-white. In the "North" Gallery at Kew, there is a portrait of one of the few remaining specimens of this--one of the rarest of the Eucalypti. Although it has the largest flowers of all the species of the genus, it is only a shrub, and has been nearly extirpated by sheep in the one district where it was known to grow. (B. M. 4333; P. M. B. xv. 29.) E. obliqua (oblique). Stringy-bark. fl., peduncles axillary or lateral, and, as well as the branches, nearly terete; umbels four to eight-flowered. l. alternate, ovate-lanceolate, 4in. to 6in. long, acuminated, very unequal at the base. h. 150ft. to 250ft. The bark of this comes off in large slabs, and is used in making wigwams and roofs; and the natives also use it when they wish to cross a river. They strip off a large concave piece, and stop up the ends with mud, so as to keep the water out, thus forming a rude canoe, in which they paddle themselves over with a piece of wood, leaving it to rot or float away. SYN. E. gigantea. (H. F. T. i., 28.) E. paniculata (panicled). fl., peduncles angular; lower ones axillary; the rest disposed in a terminal panicle; petioles 5in. long. l. lanceolate, 3in. long, and five to six lines broad, attenuated at the base. 1804. A large shrub or moderate-sized tree.

E. plurilocularis (many-celled). A synonym of E. Preissiana. E. polyanthemos (many-flowered). fl. white, small, in umbels, shortly pedunculate, and usually several together in short oblong or corymbose panicles in the upper axils, or at the ends of the branches. l. on rather long petioles, broadly ovate-orbicular, or rhomboidal, obtuse, or rarely shortly acuminate, mostly under 3in. long, passing, in older trees, into ovate-lanceolate, obtuse, and 3in. long, or more, rather rigid, with fine diverging veins, the ultra-marginal ones distant from the edge. h. various, sometimes small, at others attaining 40ft. to 50ft. SYNS. E. populifolia and E. populnea.

E. populifolia (Poplar-leaved). A synonym of E. polyanthemos. E. populnea (Poplar-like). A synonym of E. polyanthemos. E. Preissiana (Preiss's). fl. yellow; peduncles axillary or lateral, very thick and much dilated, sometimes almost winged, under 1in. long, each with three large flowers, either sessile or tapering into a very short, thick, flattened pedicel. l. mostly opposite, although petiolate, from broadly ovate to ovate-lanceolate, very obtuse, or rarely acute, 3in. to 5in. long, very thick and rigid, the veins diverging and parallel, but not close, the marginal one at a distance from the edge. h. 8ft. to 12ft. A stout, rigid shrub. SYN. E. plurilocularis. (B. M. 4266.) E. pulverulenta (powdery). fl., peduncles axillary, very short. terete, or angular, each with three flowers not large, and sessile, or nearly so. June. l. sessile, opposite, cordate, orbicular or broadly ovate, obtuse, or almost acute, quite entire, more or less glaucous. A small tree. SYNS. E. cordata and E. pulvigera. (B. M. 2087.) E. pulvigera (powdery). A synonym of E. pulverulenta. E. robusta (robust). fl., peduncles lateral and terminal, two-edged; pedicels short, compressed. l. alternate, ovate. h. 100ft. 1794. The variety rostrata has ovate-lanceolate acuminated leaves.

E. splachnicarpa (Splachnum-fruited). A synonym of C. calophylla. E. tetragona (four-angled). fl. red; peduncles axillary, short, thick, angular or flattened, with three or more rather large flowers, on thick, angular, or flattened pedicels. July. l. mostly opposite, or nearly so, the upper ones alternate, from broadly ovate and very obtuse to lanceolate-falcate and almost acute, rarely more than 4in. long, thick and rigid, with diverging, but rather distant, veins. h. varying from a low scrubby shrub to a small tree of 20ft. to 25ft. 1824. SYN. Eudesmia tetragona. (S. F. A. 21.)