FIG. 150. ARNICA MONTANA, showing Habit and Flower-head.
A. scorpioides (scorpion-like).* fl.-heads yellow, large, solitary; scape one to three-flowered. Summer. l. pale green, denticulated; radical ones on long petioles, broadly ovate; the lower stem leaves shortly stalked, amplexicaul; the upper ones sessile. h. 6in. to 12in. South Europe, 1710. Border. SYNS. A. Aronicum, Aronicum scorpioides.
ARNOPOGON. See Urospermum.
AROIDEÆ. See [Araceæ.]
ARONIA. See Cratægus Aronia and Pyrus.
ARONICUM. See [Arnica scorpioides] and Doronicum.
ARPOPHYLLUM (from arpe, a scimitar, and phyllon, a leaf; the leaf is sword-shaped). ORD. Orchideæ. Distinct evergreen epiphytes. There are about six species known, and the genus belongs to the Epidendreæ division of orchidaceous plants; their general characters are: Flowers small, numerous, in closely packed cylindrical spikes; anther-bed broad, shorter than the broad extension of the upper edge of the stigma; pollinia eight. Stems rather long, with white sheaths. They thrive well in fibrous peat, one-third turfy loam, freely interspersed with lumps of fresh charcoal and an abundance of crocks. When growing, a liberal supply of water at the roots is essential, as is also a situation near the light, where they will blossom much more profusely than if in any way shaded. The flowers last in perfection about four weeks.
A. cardinale (cardinal). fl., sepals and petals light rose; lip deep red, on upright spikes about 1ft. high. Summer. New Grenada.
A. giganteum (gigantic).* fl. dark purple and rose, densely and symmetrically arranged on the cylindrical spikes, which are from 12in. to 14in. long. April and May. l. dark green, about 2ft. long, borne on slender pseudo-bulbs. Mexico.
A. spicatum (spike-flowered).* fl. dark red, on an upright spike about 1ft. long. During winter. Guatemala, 1839.
ARRACACHA (its Spanish name in South America). ORD. Umbelliferæ. A half-hardy tuberous perennial, highly esteemed as an esculent in South America, where it yields a food, which is prepared in the same manner as potatoes, and is said to be grateful to the palate and extremely easy of digestion. It thrives best in rich loam, and is increased by divisions of the roots.