About 1,500 species; the majority within the Tropics, outside these limits especially in America. Solanum nigrum is a common weed.—The Potato-plant (Solanum tuberosum), from Peru and Chili, was introduced into Europe in 1584 by Sir Walter Raleigh. (Potatoes = Batatos). The fruits of several serve as condiments: Chilies or Pod-pepper (Capsicum annuum and longum), and the Cayenne-pepper (C. baccatum and others), whose fruits also are officinal, were brought to Europe from S. America by Columbus, and are commonly cultivated in Tropical America; Lycopersicum esculentum (Tomato) and others from Peru; Solanum ovigerum (Egg-plant); Solanum melongena, etc. Poisonous, acrid, narcotic properties (alkaloids, etc., solanine, nicotine, atropine, hyoscyamine) are found in many: Atropa belladonna (from S. Europe; the roots and leaves are officinal); Solanum dulcamara (Bitter-sweet; formerly officinal), S. toxicarium (Guiana); Datura stramonium from Asia (leaves and seeds officinal), D. sanguinea, metel, tatula, and others; Hyoscyamus (officinal: the leaves and seeds of H. niger); Nicotiana tabacum (Virginian tobacco, officinal: the leaves), N. rustica and others from Trop. America (Tobacco was introduced into Europe in 1560); Cestrum-species. Duboisia myoporoides (Australia); the leaves contain hyoscyamine and are used in medicine. A number of species of these genera are ornamental plants.
Order 2. Nolanaceæ. These most resemble the Convolvulaceæ in the corolla, but the Solanaceæ in their branching, and leaf-arrangement (in pairs, etc.). The diagram is the same as in Nicandra with 5 carpels, but the fruits of this order most frequently form, by invaginations in various directions, an ovary (with 1 style) consisting of numerous and irregularly grouped, 1-ovuled cells; the fruit is a schizocarp with many 1-seeded fruitlets.—Nolana (Western S. America): a few are ornamental plants.
Order 3. Scrophulariaceæ. The flower is hypogynous, ☿, zygomorphic, with the usual type: S5, P5, A5, and G2, the latter placed in the median plane; some genera have all 5 stamens developed (Fig. [562] A), but most frequently the posterior one is suppressed and the flower becomes didynamous (Fig. [562] B). The fruit, as in the capsular-fruited Solanaceæ, is a bilocular, 2-valved capsule, with a thick, axile placenta, and most often septicidal dehiscence (Fig. [563] C). The numerous seeds are not reniform as in many Solanaceæ, and have a straight, or only slightly curved embryo, with abundant endosperm (Fig. [563] D).—The majority are herbs; some are arborescent; the leaves are opposite or scattered, but stipules are wanting as in the whole family.
The Scrophulariaceæ are closely allied to the Solanaceæ, and there is, properly speaking, no characteristic feature which absolutely separates them. The somewhat irregular corolla, with five stamens of unequal length in Verbascum, is also found in Hyoscyamus; curved and straight embryos are found in both orders. The activation of the corolla in the Scrophulariaceæ is simple imbricate, in the Solanaceæ most frequently folded imbricate (in Atropa and those allied to it, imbricate without folding). The genera (about 164) are distinguished according to the form of the corolla, number of stamens, inflorescence, arrangement of the leaves, etc. Verbascum belongs to the most primitive 5-stamened forms, and from it proceed a long series down to Veronica, with only two stamens and most frequently the posterior sepal suppressed.
Fig. 562.—Diagrams. A Verbascum; B Linaria; C Veronica.
1. Antirrhineæ, Snapdragon Group. This has most frequently a descending æstivation of the petals (the posterior petals are outside the lateral ones, which again enclose the anterior; Fig. [562] A, B). The plants belonging to this group are not parasites.
a. 5-stamened.—Verbascum (Mullein, Fig. [563] A) has a slightly irregular, rotate corolla; five stamens (frequently covered with woolly hairs), of which the two anterior ones are the longer and differ often also in other respects. The inflorescences are racemose, often with several series of accessory dichasia in the axil of each primary floral-leaf. The leaves are scattered and, together with the stems, are often covered with a grey felt of branched hairs.
Fig. 563.—Verbascum thapsiforme.