Erythraea
(from erythros, red; colour of flowers of some species). Centaury. SYNS. Gyrandra and Hippocentaurea. ORD. Gentianeae. A genus of above thirty species of small hardy or half-hardy annual, biennial, or perennial plants. Flowers pink, yellow, or rarely white, terminal, sessile, or pedicellate. Leaves sessile, opposite, decussate; radical ones rosulate. Erythraeas form elegant little plants for rockwork, grown in a sandy loam soil. Increased by seeds, or by divisions.
E. Centaurium (Centaury). fl. rose-coloured. l. ovate-lanceolate. Stem dichotomously panicled, corymbose. h. 3in. to 12in. North Africa, Europe (Britain). Annual. This plant was formerly much employed by physicians as a vermifuge. (Sy. En. B. 909.)
E. diffusa (diffuse).* fl. bright deep rose. l. fleshy, entire, glabrous, shining, generally concave. h. 2in. to 3in. Western Europe. Perennial. A charming little rock plant.
E. littoralis (shore). fl. pink, crowded, sessile, fasciculate. June. l. ovate-oblong, obtuse. Stem simple or branched, dwarf, tetragonal. h. 3in. Europe (Britain). Biennial. (Sy. En. B. 908.)
E. Muhlenbergi (Muhlenberg's).* fl. of a deep pink colour, with a greenish-white star in the centre. Spring. l. oblong-obtuse, the floral ones lanceolate. Branches numerous, slender. h. 8in. California. An excellent plant for growing on rockwork, or for margins of a loamy border.
E. venusta (charming). fl. usually pink, star-like; corolla 1in. in diameter; tube slender; lobes of the limb elliptic, obtuse, deep rose-coloured, yellow at the base, as long as the tube. August. l. in pairs, scattered, sessile, 1/2in. to 1in. long, oblong or ovate-oblong, rounded at the apex; base rounded or cordate; upper and floral leaves narrower and acute or acuminate. Stem simple or cymosely branched above, few-flowered. h. 6in. to 10in. California, 1878. A slender erect hardy annual. (B. M. 6396.)