Nature (journal)/Volume 1/Number 9/Botany

Prof. Delpino, of Florence, has published some interesting researches on the relation between the diffusion of plants and animals. "The life of every plant has three principal objects: its nourishment, its reproduction, and the distribution of its seeds; for each of these three objects special biological conditions being requisite. The fertilisation of many plants can be effected only by some particular animal; as Arum italicum, Aristolochia, and Asarum, by gnats; the fig tribe by different species of Cynips (or gall-fly); Arum dracunculus, Stapelia, and Rafflesia, by blue-bottle flies; many others by different kinds of flies or bee-like insects (Hymenoptera), and some even by small birds belonging to the family of Trochilidae, or humming-birds; Rosa, Paeonia, and Magnolia grandiflora, by beetles of the chafer tribe; others again by small slugs. If in any particular locality the animal necessary for the fertilisation of a particular plant is absent, it is certain that the plant cannot spread; and thus the conditions for the diffusion of plants are dependent on the geographical distribution of animals. A remarkable illustration is furnished by two plants belonging to the sane genus, grown in the botanic gardens in Italy, Lobelia syphilitica and L. fulgens; the flowers of the former are abundantly visited by Bombus terrestris and italicus, and freely produce seeds; the latter, notwithstanding its beauty and its great store of honey, is never visited by insects in the neighbourhood of Florence, and never bears seeds spontaneously, but can be readily fertilised by artificial impregnation. Prof. Delpino conjectures that it is naturally fertilised by humming-birds. He believes that the scarlet colour of the corolla, so common in the tropics, but comparatively rare with us, is especially attractive to small birds, but offensive rather than otherwise to Hymenoptera. As a rule, scarlet flowers are large, bag-like in form, horizontal in position, and with the nectar completely separated, which would of itself perfectly prevent their fertilisation by insects. The largest European flowers, such as the paeony and large bind-weed (Convolvulus sepium) are fertilised by sphinxes and rose-chafers. [Botanische Zeitung.]

This magnificent plant has thriven to an unprecedented degree during the past summer in the botanic Garden at Ghent. Several leaves have attained a diameter of nine feet, and have supported a weight of 250 lbs, and one even the enormous weight of 500 lbs. Seven of the gigantic leaves completely covered the basin of 164 feet square, and they were obliged to be removed to make room for the young leaves which continued to develop in the centre. Every four or five days a fresh flower appeared, which lasted only two days, or rather two nights, opening in the morning of a perfectly white colour, diffusing about five or six P.M. a very powerful odour of vanilla, closing the next morning at 8 or 8 A.M., opening the same day towards evening, this time of a beautiful carmine, and finally closing the next morning. The magnificent leaves last through the summer; the plant begins to dwindle in October, and dies towards December. About this time the seeds, which have been obtained by artificial fecundation, arrive at maturity. They are sown in January, and appear above the ground in about six weeks, Their infancy is very critical; but once past this period, the young plants grow with astonishing rapidity; the plant in the Ghent Botanic Gardens, unquestionably the finest that has ever been cultivated, arrived at its full development in five months.