FIG. 138. ARABIS ALPINA, showing Habit and Flowers.
A. alpina (alpine).* fl. white, smaller than those of A. albida; racemes terminal; pedicels longer than the calyx, which is smoothish. March to May. l. many-toothed, lanceolate, acute, villous with branched hairs; radical ones somewhat stalked; cauline ones cordate, clasping the stem. h. 6in. European rocks, in sunny places, 1596. There are one or two varieties, including a variegated-leaved form, in cultivation. See Fig. 138.
FIG. 139. ARABIS ARENOSA, showing Habit and Flowers.
A. arenosa (sand-loving).* fl. rose coloured, very rarely white or bluish; petals obovate; pedicels spreading. April to July. l. villous, with forked hairs; radical ones pinnatifid, with the upper lobes much larger than the lower; cauline ones deeply toothed. Stem branched, hispid, with simple hairs. h. 6in. Middle Europe, 1798. See Fig. 139.
A. blepharophylla (fringed-leaved).* fl. rosy purple; petals roundish, narrowing to the base, with slender claws. Spring. l. naked, except the margins, which are fringed with very stiff hairs; radical ones spathulate; cauline ones oblong, sessile. h. 3in. to 4in. California, 1874. This succeeds best in a cool frame, where it will flower in January.
A. caucasica (Caucasus). A synonym of [A. albida.]
A. lucida (shining).* fl. white; petals entire, narrowed at the base, twice as long as the calyx. Summer. l. obovate, thickish, shining, clasping the stem. h. 4in. to 6in. Hungary, 1790. A very pretty species, with a dwarf habit; it is especially adapted for edgings, borders, or rockwork.
A. l. variegata (variegated).* A great improvement upon the type, being broadly edged with yellow, and the green somewhat lighter. When grown in tufts or as edging, it is very effective, and should be prevented from flowering. This exceedingly desirable variety is a gem for the rockwork, and when seen in crevices, or in bold tufts, it is very striking. It must be increased by slips or rootlets, which should be taken in early summer.
A. mollis (soft). fl. white, in terminal racemes. May to July. l. grossly toothed, somewhat pubescent, with small stellate hairs; lower ones on long petioles, cordate-roundish; cauline ones ovate-cordate, clasping the stem. h. 2ft. Caucasus, 1823.
A. petræa (rock).* fl. white; petals ovate, with stalks. June. l. smooth, ciliated or scabrous, with simple or bifid radical ones on longish stalks, entire, toothed; cauline ones oblong-linear, entire, or toothed. h. 3in. or 4in. Britain.
A. præcox (early). fl. white; petals obovately cuneated, double the length of the calyx. April to June. l. oblong, acute, sessile, quite entire, smooth. Stem covered with close pressed rigid hairs. h. 6in. to 9in. Hungary.
A. procurrens (procurrent). fl. white; petals obovate, double the length of the calyx. May and June. l. ovate, quite entire, smooth, ciliated with two-parted hairs; radical ones narrowed into a petiole; cauline ones sessile, pointed. Stolons creeping. h. 9in. Servia, 1819. There is a brilliantly variegated form of this pretty species well worth growing.
A. rosea (rosy).* fl. rosy purple; petals oblong, somewhat wedge-shaped, double the length of the calyx; pedicels longer than the calyx. May to July. l., cauline ones oblong, somewhat cordate, and rather stem-clasping, scabrous with branched hairs. h. 1ft. Calabria, 1832.
A. verna (spring). fl. small, purple, with a white claw; pedicels shorter than the calyx. May to June. l., cauline ones cordate, clasping the stem, toothed, scabrous with three-parted hairs. h. 3in. to 6in. South Europe, 1710. The best annual species.
ARACEÆ or AROIDEÆ. An extensive order of herbaceous plants, with tuberous rhizomes. Flowers on a spadix, unisexual or hermaphrodite, protected by a spathe. Leaves large, radical. Well known genera belonging to this order are: Alocasia, Arum, Caladium, Colocasia, and Dieffenbachia.
ARACHIS (from a, without, and rachis, a branch; plant branchless). Ground or Earth Nut. ORD. Leguminosæ. A stove annual, of economical value. Corolla resupinate; calyx a long tube, with a bilabiate limb; ovary stipitate, inclosed in the tube of the calyx; the stipe at first short, but afterwards becoming elongated. Sandy loam is the soil most suitable for their cultivation. Seeds should be sown in heat; and, when the plants have grown to a sufficient size, they should be potted off singly, and placed among other stove annuals. After the plant has finished flowering, and the pods begin to lengthen, the pedicels force them into the earth, where they ripen their seeds.
A. hypogæa (underground). Monkey Nut. fl. yellow, five to seven together in the axils of the leaves. May. l. abruptly-pinnate, bearing two pairs of leaflets, without any tendril; stipulas elongated, adnate to the petioles. h. 1ft., or procumbent. South America, 1812. See Fig. 140.
ARACHNIMORPHA. A synonym of Rondeletia (which see).