V. spicata: stems ascending or erect, 1/2-1 foot high, usually simple; leaves oblong or the lower ones ovate, downy, slightly crenate; flowers clear blue, in dense terminal spikes. - Hilly pastures, in limestone districts, rare. Fl. July, August.
V. serpyllifolia: stems shortly creeping, much branched, forming dense, leafy tufts, the flowering branches ascending, 2-6 inches high; leaves ovate, slightly crenate, glabrous; flowers very small, pale blue or white with darker streaks, sessile or shortly stalked, in terminal racemes, the bracts rather large and leaf-like. - Pastures, fields, and waste places. Fl. May, June.
V. arvensis: annual; stems hairy, 2-6 inches high, erect, simple, or sometimes diffuse and branching at the base; leaves ovate, toothed, the upper floral ones lanceolate; flowers small, sessile, forming terminal, leafy racemes, blue or nearly white. - Cultivated and waste places. Fl. May, June.
** Flowers in axillary racemes.
V. officinalis: stems much branched, creeping and rooting, 1/2-1 foot long; leaves obovate or oblong, toothed, hairy; spikes or racemes hairy, axillary, sometimes proceeding from the upper axils, the flowers nearly sessile, small, pale blue. - Dry banks and heaths. Fl. June to August.
V. Anagallis: stems erect, branching, 1/2-2 feet high, glabrous; leaves lanceolate, sessile or clasping, toothed; racemes numerous, axillary, opposite, i. e. in the axils of both leaves of each pair, the flowers small, pedicellate, pale blue. - Wet ditches, and by streams and ponds. Fl. July.
V. Beccabunga: stems procumbent or floating at their base, rooting, the flowering branches ascending, glabrous; leaves stalked, oblong, obtuse, slightly toothed; flowers small, blue, in opposite axillary racemes. - Brooklime. - Wet ditches, and by streams and ponds. Fl. June, July.
V. scutellata: stems slender, ascending or spreading, about 6 inches high, glabrous, rarely downy; leaves linear-lanceolate; flowers few, in slender racemes, alternately from one axil only of each pair of leaves, small, pale pinkish-blue. - Marshes, ditches, and wet places. Fl. July, August.
V. Chamsedrys: stems weak, ascending, about a foot long, with two opposite lines of hairs; leaves stalked, ovate-cordate, crenate, hairy; racemes longer than the leaves, with large bright blue flowers, on longish pedicels; capsule flat, very broad at the top. - Woods, banks, etc. Fl. May, June.
V. montana resembles this, but is more diffuse, with looser and more slender racemes of flowers, the stem hairy all round, and the capsule broadest in the middle.
*** Flowers solitary, axillary.
V. hedersefolia: annual; stems procumbent; leaves broadly orbicular, with 5-7 coarse teeth, the middle one broad, rounded; flowers pale blue, the sepals broadly heart-shaped. - A weed of cultivation. Fl. May, June.
V. agrestis: annual; stems hairy, branched, procumbent, 1/4-1 foot long; leaves ovate, toothed, the lowest opposite, but mostly alternate, each with a single small blue or pinkish-white flower in its axil, the sepals oblong; capsule of 2 ovoid, erect lobes. - A common weed. Fl. April to September.
V. polita is a variety with ovate sepals, and larger blue flowers; and the allied V. Buxbaumii, another weed of cultivation, closely resembles this species, but is larger in all its parts, with the flowers bright blue, and the lobes of the capsule broad and divaricate.