Mertensia
(named in honour of Professor Francis Charles Mertens, 1764-1831, a German botanist). SYNS. Casselia, Hippoglossum, Oreocharis, and Steenhammera. ORD. Boragineae. This genus comprises about fifteen species of very handsome, hardy, perennial, glabrous or pilose herbs, natives of Eastern Europe, extra-tropical Asia, and North America. Flowers blue or purplish, pedicellate, ebracteate; racemes terminal, or cymes loosely branched, few-flowered, unilateral, sometimes paniculate. Leaves alternate, often pellucid-dotted. The species are of very easy culture in ordinary garden soil; they form admirable subjects for mixed borders, copses, and rockwork. Propagated by divisions in autumn; or by seeds, sown as soon as ripe.
M. alpina (alpine).* fl. light blue, disposed in close, or at length loose, clusters, of which each stem bears from one to three. Spring and summer. l. bluish-green, oblong, somewhat spathulate or lanceolate, rather obtuse. h. 6in. to 10in. Rocky Mountains, 1875. A lovely little alpine. M. alpina (alpine), of Hooker. A synonym of M. lanceolata. M. dahurica (Dahurian). fl. bright azure-blue, drooping, in racemose panicles. June. l. ovate, roughish, slightly glaucous, and clothed with small decumbent hairs. Stems erect, branching, angular, furrowed, hairy. h. 6in. to 12in. Dahurica. A pretty species, with a very slender habit, and requiring a sheltered position. (B. M. 1743, under name of Pulmonaria dahurica.) M. lanceolata (lanceolate).* fl. drooping; bracts leafy; calyx shorter than the corolla tube, five-cleft to the middle or lower; segments oblong and obtuse, or lanceolate and acute; corolla light or dark blue, with a cylindric tube; limb campanulate, very shortly five-lobed. May. l. sessile, chiefly cauline, linear-oblong or spathulate, radical often broader, acute or obtuse; upper surface smooth or muricate; margin ciliate. Stems simple, erect, slender. h. 6in. to 12in. Rocky Mountains, 1874. (B. M. 6178, under name of M. alpina.) M. maritima (sea). Oyster Plant. fl. blue, erect, disposed in terminal corymbose racemes. July. l. ovate or oblong, acutish; the upper ones stem-clasping. Stems procumbent, branched. Northern coast regions of Northern hemisphere (Britain). SYN. Pulmonaria maritima. (Sy. En. B. 1099.) M. paniculata (paniculate). fl. purplish-blue; corolla somewhat funnel-shaped, three or four times the length of the lanceolate-linear acute divisions of the calyx. July. l. ovate and ovate-lanceolate, taper-pointed, ribbed, thin. h. 1ft. to 2ft. North America. Plant erect, roughish, more or less hairy. (B. M. 2680 and B. R. 146, under name of Pulmonaria paniculata.) M. sibirica (Siberian).* fl. purplish-blue, terminal, pedicellate, disposed in elongated, conjugate racemes, with a flower in the fork. May to July. l. rather fleshy, glabrous; radical ones cordate, roundish-obtuse, or broad-elliptic; cauline ones ovate, acute. Stems erect, simple. h. 6in. to 18in. East Asia and North America, 1801. A very pretty species, varying in the colour of its flowers. SYN. Pulmonaria sibirica. There is a white-flowered form in cultivation.
M. virginica (Virginian).* Virginian Cowslip. fl. purple-blue, tubular, about 1in. long, disposed in gracefully-drooping terminal clusters. Spring and summer. l. lanceolate-ovate, lower ones 4in. to 6in. long, 2in. to 3in. broad, shortly stalked. h 1ft. to 2ft. Virginia, 1799. (B. M. 160, under name of Pulmonaria virginica.)