Family 6. Scitamineæ.
The flowers belong to the ordinary monocotyledonous type. They are hermaphrodite, epigynous, and have either a petaloid perianth, or calyx and corolla; they are, however, zygomorphic or unsymmetrical, and of the stamens most frequently only one is completely developed, the others being generally represented by petaloid staminodes. The ovary has 3 loculi, more rarely it is unilocular with the suppression of 2 loculi. Endosperm is absent (except Zingiberaceæ); but, on the other hand, there is a large perisperm. To this family belong large, glabrous, especially perennial herbs with rhizomes; leaves large, distinctly divided into sheath, stalk, and blade, the latter being more or less elliptical or lanceolate, entire, with pinnate venation, and always with a very well-pronounced midrib, gradually tapering towards the apex, and giving off numerous branches, which run outwards, towards the margin, at a larger or smaller angle; these lateral veins are closely packed, and parallel, but with only weak, connecting branches between them; the leaves, therefore, are easily torn pinnately (Figs. [314], [317]). The leaf-sheaths close tightly round each other and form a false stem.
This very natural family comprises orders closely connected with each other, but is not itself nearly allied to any other family. First in the series stands:—
Order 1. Musaceæ. The petaloid perianth is strongly zygomorphic, the anterior leaf being very large (a kind of “labellum”), the posterior one small; only the posterior stamen is wanting, or is rudimentary, the other five are developed, and have quadrilocular anthers; ovary, 3-locular. Seed with straight embryo in mealy perisperm.
Fig. 314.—Two Musa-species.
The best-known genus is Musa, the Banana (Fig. [314]). From the short rhizome arise enormously large, spirally-placed leaves, whose sheaths envelope one another, and form an apparently aerial stem, several metres in height. The inflorescence is a terminal spike with floral-leaves placed spirally, and sometimes magnificently coloured; in the axils of each of these several flowers are situated in two transverse rows (accessory buds); the lowest flowers in the inflorescence are ♀, the central ones ☿, the upper ones ♂, so that fruits are only found in the lower region of the inflorescence, the remaining portion persisting as a naked axis after the floral-leaves and flowers have fallen off; the inflorescence terminates in an ovoid bud formed by the flowers which have not yet opened (Fig. [314], the left-hand figure). The perianth-leaves are united (except the posterior one). The fruit (known as a “Banana”) is a berry, having the form of a smooth, short, three-cornered Cucumber (as much as 30 cm. in length); inside the tough skin is found a farinaceous, aromatic pulp. No seed is developed in the cultivated species.—Several Musa-species are cultivated in the Tropics for the sake of the fruit (M. paradisiaca, M. sapientum); for the fibrovascular bundles, M. textilis (Manilla Hemp).—Their home is, no doubt, the Tropics of the Old World; they were introduced into America before the arrival of Europeans. Musa ensete has dry, leathery fruits; an ornamental plant.
In Musa the barren, posterior stamen belongs to the inner whorl; and also in Strelitzia and Ravenala; the latter may have all 6 stamens developed. In Heliconia, on the contrary, it belongs to the outer whorl; in Heliconia the perianth-leaves are differently arranged, and there is only one ovule in each loculus. The three latter genera have dry fruits and leaves arranged in two rows. In the “Travellers’ Palm” (Ravenala madagascariensis) the foliage-leaves form an enormous fan.—Tropical; about 50 species.
The order may be divided as follows:—1. Museæ: Musa, Ravenala, Strelitzia in the Old World. 2. Heliconiæ: Heliconia in the New World.
