| + | Leaves opposite, compound (in proper representatives of the genus), the terminal lft. often represented by a tendril: fls. large, tubular or bell-shaped, enlarged above the calyx, obtusely 5-lobed, and more or less 2-lipped, the calyx slightly or not at all toothed; stamens 4, paired, and sometimes a sterile rudiment: fr. a 2-celIed septifragal caps, flattened parallel with the partition; valves thickened; seeds winged.—The genus Bignonia is variously understood. By Bentham & Hooker it is regarded as a polymorphous group of 150 or more species; by Schumann (in Engler & Prantl) it is reduced to 2 species with claw-like (not disk-bearing) tendrils, B. exoleta, Vell., and B. Unguis-cati, Linn. By the former authors Bignoniaceae is held to contain about 50 genera, and by the latter about 100. Schumann distributes the bignonias of Bentham & Hooker into several genera: the common East American B. capreolata goes to Doxantha, a disposition that has not been accepted by American botanists. As here employed, Bignonia is deprived of many of the tropical species that have been placed in it in horticultural literature, and the student is referred to Clytostoma, Cydista, Phaedranthus, Pithecoctenium, Pyrostegia, Tabebuia and others. Very recently the name Bignonia has been used for the species described in this work under Campsis, because Bignonia originally was based mainly on B. radicans = Campsis radicans. In this case, the generic name for B. exoleta and B. Unguis-cati above becomes Doxantha; otherwise, this latter name remains a synonym of Bignonia, although, as stated above, Schumann has used it as the generic name of B, capreolata; but the correct name for this plant appears to be Anisostichus capreolata, of Bureau. The other species described here under Bignonia probably belong to different genera, but their correct botanical affinity has not yet been ascertained. |
| + | The bignonias are American climbers, mostly tropical, some of them and their allies constituting lianas if great length; and the profusion and beauty of their flowers makes them conspicuous and interesting. The stem of some species shows a 4-parted or cross-like arrangement in cross-section, whence the name "cross-vine;" and on this account, some of the natives of Spanish America attribute sacred virtues or attributes to the plants, calling them "bejucos de la cruz." Fig. 553. |
| + | The bignonias (using the term in the horticultural sense) are strong and rapid-growing evergreen greenhouse climbers, requiring considerable space for their best development, such as the roof of a large conservatory, or the back wall of a lean-to greenhouse. If convenient, they should be planted out under the plant stage of the greenhouse, or otherwise in boxes placed on the stage. A box 5 feet by 1½ feet and 1 foot deep will be found a convenient size for them. As with most greenhouse climbing plants, the roots like considerable freedom; but with bignonias the roots must be somewhat, restricted (though not to the limitations of a flower-pot), otherwise an immense growth and few flowers will be the result. They are not very fastidious as to soil. A good, fibrous loam, to which one-third well-decomposed cow or sheep manure has been added, suits them admirably. A winter temperature of 45 to 50°, with a gradual rise as the days lengthen, should be given them, admitting air freely whenever the weather is favorable. They like plenty of moisture at the roots—especially during the spring and summer (the growing season)—but perfect drainage should be insured, as the soil at no time must become saturated or sour. Except when in flower, a good syringing on all fine days will be very beneficial. They should also be sprayed once or twice a week with a moderately strong solution of kerosene emulsion, or kerosene and water, to keep them free from mealy-bug, as they are very subject to this pest. The vines should be trained so as to allow a free circulation of air among the branches for the purpose of ripening the wood, as upon this depends the assurance of flowers. All superfluous branches and weak shoots should be removed, and before the growing season begins all the branches should be shortened from 1 to 3 feet, according to their strength; this will throw the energy of the plant into the lateral buds, which will produce the flowering branches, providing the wood has been properly ripened the previous season.—Propagation is effected by cuttings taken in late spring and inserted in sand under a bell-glass, or in a propagating-box, in a warm temperature. Choose, if possible, stout, short-jointed lateral growths for the purpose. They must be carefully watered until rooted, which usually takes from six to ten weeks. (E. J. Canning.) |