A. Cunninghami (Cunningham's).* l. on the sterile branches needle-shaped, obscurely quadrangular, rigid, acute; on the fertile branches shorter, stouter, closely appressed, bright green; upper branches ascending, lower ones horizontal. h. 100ft. Moreton Bay. This fine species we have found to be quite hardy on the south-west coast of England.
A. C. glauca (milky-green). A very handsome variety, with silvery glaucous leaves.
A. excelsa (lofty).* The Norfolk Island Pine. l. awl-shaped, curved, sharply acuminated, bright green, densely packed on the frondose, deltoid, horizontal, or pendulous branches. When well grown, this is a beautifully symmetrical greenhouse or conservatory species, attaining to a height of 150ft., and a circumference of 20ft. or more. Norfolk Island. This is especially desirable in a small state. There are several varieties known, the best being: A. e. glauca, having lighter green, and very glaucous foliage; and A. e. robusta, which is larger in all its parts. See Fig. 144.
A. Goldieana (Goldie's).* Allied to A. Rulei. l. produced in whorls, pendulous, dark green, varying in size. New Caledonia. Most distinct and elegant for conservatory decoration.
A. imbricata (imbricated).* The Monkey Puzzle. fl., male and female catkins on separate trees; the males are six or seven in a cluster, pedunculate, yellow, and oval with numerous scales, imbricated, long, and recurved at the points; the female catkins are oval, with numerous wedge-shaped scales, with narrow oblong brittle points; they are produced at the ends of the branches. cones, when fully ripe globular, from 3in. to 4in. in diameter, dark brown. The branches are horizontal, inflexed, and ascending at the extremities, and are produced in whorls. l. ovate-lanceolate, sessile, thickened at the base, stiff, leathery, straight, somewhat keeled-shaped below, and strongly mucronate at the apex; verticillate, with seven or eight in a whorl, imbricate, and closely encircling the branches, concave, glabrous, shining, marked with longitudinal lines, dotted on both sides. h. 50ft. to 100ft. Chili, 1796. A well known hardy tree, of striking aspect, and indispensable to Arboreta and shrubberies. See Fig. 145.
A. Rulei (Rule's).* male cones oblong obtuse; female cones oval. l. oblong-lanceolate, with a prominent dorsal nerve, more closely appressed, and less sharply pointed than in the foregoing species; imbricated in four rows. Branches horizontal; branchlets often quite pendulous. h. 50ft. Papuan Archipelago.
A. R. elegans (elegant).* l. smaller; whorls of branches closer together; branchlets more slender. An elegant form; and, from its comparative dwarf and graceful habit, should be very generally grown.
ARBOR. A tree. A perennial plant, having a distinct bole or trunk, from which the main branches grow.
ARBORESCENT. Having a tendency to become a tree.
ARBORETUM. A collection of hardy trees formed for pleasure or instruction, and which, when well managed, is a source of much interesting study. They afford shelter, improve the local climate, renovate bad soils, &c., and also, by concealing or hiding disagreeable objects, heighten the effect of agreeable ones, create beauty, and add value. A properly arranged Arboretum should be constructed with a view to picturesque beauty, and not systematically, as is usually the case in Botanic Gardens, although scientific purposes are best served by a systematic arrangement.
ARBOR-VITÆ. See Thuja.
ARBOUR. A seat surrounded by lattice work, covered by Vines, Wistarias, or other climbing plants.
ARBUTUS (from arboise, Celtic for austere bush; in allusion to the austere quality of the fruit). Strawberry Tree. ORD. Ericaceæ. Trees and shrubs, with evergreen alternate laurel-like leaves. Corolla globose, or ovately campanulate; petals five, reflexed. Very ornamental subjects for lawns and shrubberies, thriving well in a light sandy or peaty soil. They may be propagated by seeds, which should be sown in sand during March; by budding, and by inarching; the first mentioned method is the one most generally employed, with good results. The various sorts may be grafted, budded, or inarched upon A. Unedo. The greenhouse species are rare in cultivation, but their management does not materially differ from other plants requiring a similar temperature.
A. Andrachne (Andrachne).* fl. greenish-white; panicles terminal, erect, clothed with viscid down. March and April. l. oblong, bluntish, entire in some, a little serrated in others, glabrous. h. 10ft. to 14ft. Greece, 1724. A fine ornamental tree.
A. A. serratifolia (saw-edge-leaved). fl. yellowish, disposed in rather large terminal clusters. l. serrated, and narrower than those of the species. SYN. A. serratifolia.
