Nierembergia
(named after John Eusebius Nieremberg, 1595-1658, a Spanish Jesuit, author of a work on the Marvels of Nature). ORD. Solanaceae. A genus comprising about a score species of mostly half-hardy, elegant, perennial herbs, creeping, diffuse, or rarely almost erect, often slender and glabrous; they are natives of extra- and sub-tropical America. Flowers pale violet or whitish, on solitary pedicels; limb of corolla often elegantly expanding; tube slender, elongated. Leaves entire. The hardy species prefer a light but not very dry soil, and are all easily increased by cuttings, placed in a gentle heat. The species best adapted for growing in cool houses are of comparatively easy culture. They thrive best in a compost of three parts good sandy loam, and one of thoroughly decomposed manure and sharp sand. These kinds should be propagated, during August, by cuttings, which, when well rooted, should be potted off singly and placed for the winter on a light, airy shelf in the greenhouse; only enough water being given to prevent flagging. In February or March, shift into 5in. pots, in which the plants may be allowed to flower, or they may be transferred afterwards to beds or vases outside. Propagated also by seeds, which should be sown in a warm greenhouse during spring or in autumn, and the plants grown on in the way recommended above for cuttings. The undermentioned species are those best known to cultivation. N. calycina (large-calyxed).* fl. yellow at the base, with a yellowish tube and a white limb; peduncles lateral, one-flowered, short. September. l. opposite and alternate, roundish-obovate, petiolate. Stems procumbent. Buenos Ayres, 1834. Plant clothed with glandular pubescence. Half-hardy. (B. M. 3371; S. B. F. G. ser. ii. 319.) N. filicaulis (thread-stemmed).* fl. usually lilac, with a yellow centre; tube slender, glandular; peduncles opposite the leaves, one-flowered. May. l. linear-lanceolate, acute or obtuse. h. 6in. to 12in. Buenos Ayres, 1832. Plant glabrous, erect, filiform. Greenhouse. (B. M. 3370; S. B. F. G. ser. ii. 243.) N. frutescens (shrubby).* fl. delicate blue, shaded to white at the edges, about 1in. in diameter, densely produced on much-branched flax-like stems. Early summer. l. linear, 1 1/2in. to 2in. long. h. 1ft. to 1 1/2ft. Chili, 1867. A handsome hardy species, with a shrubby habit. N. gracilis (slender).* fl. terminating the young branches; limb white, streaked with purple, with a yellow centre; tube very long. Summer. l. linear, sub-spathulate, obtuse. Stems erectish. h. 6in. to 12in. Buenos Ayres, 1831. Plant downy, half-hardy. An excellent and very floriferous species, well adapted for pot culture and greenhouse decoration. (B. M. 3108; S. B. F. G. ser. ii. 172.) N. rivularis (brook-loving).* fl. white, with a yellowish, and, sometimes, a rosy tinge; corolla bell-shaped, about 1in. across, with a very slender tube, 1in. to 2 1/2in. long. July. l. very variable in size, oblong or spathulate, obtuse. Stems much branched and matted, slender, smooth, creeping and rooting. La Plata, 1866. A handsome hardy perennial when well grown; moisture and a little shade being the chief conditions required. In bare places, or the more moist parts of rock work, it may be grown with capital effect; but the patches should be broad. It also forms a good surfacing subject for leggy plants or shrubs. Propagation is best effected by divisions in spring, just as the new growth commences. (B. M. 5608.) N. Veitchii (Veitch's). fl. pale lilac, with a very slender corolla tube, 1in. long. l. ovate-oblong. Stems slender, branching, prostrate. South America, 1866. Greenhouse. (B. M. 5599.)