FLOWER GARDEN. WITH COLOURED PLATES VOL. II Pages 145-146 CASSELL & COMPANY, LIMITED : LONDON, PARIS & NEW YORK. 1883
This brilliant aquatic, though an old inhabitant of our gardens, is still a rarity, appearing only in first-class collections. Nor has it been fortunate in the artists who have attempted to fix its likeness on paper; the early figure in the "Botanist's Repository" is particularly unsatisfactory. We have, therefore, gladly availed ourselves of the opportunity of producing a true representation of a fine specimen which flowered at Syon. Roxburgh merely says of this plant that it is a native of India, flowering during the rainy season, and by no means so common as the Nymphæa Lotus ; nor do we find other details in the works of Indian writers. It is probable that more species than one may be included in this name, for Roxburgh mentions a small rose-coloured with from twenty to twenty-five stamens, and Dr. Wight figures as the N. rubra a plant with at least sixty long narrow yellow stamens. Neither of these corresponds with that before us, which we presume to be the common Indian plant; in which we find strongly seven-ribbed sepals, crimson inside, succeeded by broad satiny spreading crimson petals, the central of which are linear, blunt, erect, curved inwards, and gradually passing into the crimson stamens, which they nearly conceal. The stigmatic apparatus consists of fifteen papillose rays, which are free and smooth at their extremeties, curved inwards and fleshy, surrounding a central nipple; as in Nymphæa alba and others. To these extremities it is desirable that anatomists should direct their attention, inasmuch as their peculiar construction indicates some very peculiar function. In Nymphæa alba they are deep yellow, firm like wax, with a strong even epiderm, and are filled with a soft loose cellular substance, containing an abundance of large coarse scabrous hairs, sometimes half circular, sometimes straight, all placed parallel with the external surface. They are evidently analogous to the scabrous hairs so abundant in the air cells of Nymphæa. The yellow ends of the stigmatic rays of Nuphar do not contain this tissue. Nor is there anything in Victoria, much as that plant abounds in stellate internal hairs, which is identical with the extremities of the stigmatic apparatus Nymphæa. Other peculiarities are observable among water-lilies, and are, it must be supposed, connected with their vital functions, although we know not in what way. The pollen, for instance, varies greatly in some of the genera. In Nymphæa rubra it is simple, globose, and perfectly smooth ; in Nymphæa alba it is similar, but the surface is slightly rough. In the yellow water-lily (Nuphar lutea), on the contrary, it is covered with such long points that the pollen-grains hold together in masses, like burs. On the other hand in Victoria, where the pollen is much larger, the grains are perfectly smooth and constantly grow together in threes or fours. In the Crimson Water-lily the leaves are closely covered on the underside with a soft felt of delicate hairs, which are quite perceptible to the touch. Examined with the microscope the hairs are found to be simple attenuated smooth cones, with no tendency to branch or become stellate. Not a trace is perceptible on the leaf of those curious perforations in Victoria which have been mistaken for stomates, but which in reality are passages through the thickness of the leaf, and are altogether, as far as we know, sui generis. We may as well take the present opportunity of saying of these perforations that instead of being stomates, which are also present in Victoria, they are formed by a depression of two corresponding points of the upper and under surface of the leaf, and are at first closed by a transverse membrane. After a short time this membrane disappears, and a clear passage through the leaf is thus effected. Possibly this contrivance may be intended to allow the air to escape upwards, that would otherwise collect below the under surface of the leaves in Victoria in the spaces included by its deep ribs, and thus prevent that contact of water which may be assumed to be necessary to the health of that extraordinary aquatic.
|