Fig. 150.—Chloranthy, &c. Epilobium hirsutum.
Chloranthy.—The term phyllomorphy is applied to the individual parts of the flower which assume the form and appearance of leaves. By chloranthy it is to be understood that all, or the great majority of the organs of the flower assume these conditions.[280] In chloranthy, as here defined, there is no unusual number of buds, as there is in prolification, but the appearance of the flower-bud is so changed as to make it resemble more closely a leaf-bud than a flower-bud. There is not necessarily any increase in the number, or any alteration in the position of the buds, but the form and appearance of the latter differ from what is usual. Chloranthy, then, is a more complete form of frondescence. Owing to the vagueness with which the word has been applied by various authors, it becomes very difficult to ascertain whether the recorded instances of chloranthy were really illustrations of what is here meant by that term, or whether they were cases of mere virescence (green colour, without other perceptible change), or of prolification (formation of adventitious buds). It is, therefore, quite possible that some of the instances to be now mentioned were not strictly cases of chloranthy.
Fig. 151.—a. Open leafy carpel of "green rose," with two deformed ovules. b. Ovule separate. c. Primine removed. d. Secondine and nucleus, with the bulbous end that projects through the micropyle.
Seringe[281] has described a malformation in Diplotaxis tenuifolia in which all the floral organs were replaced by sixteen distinct leaflets which had preserved their proper relative position. The Cruciferæ, of which family the last-named plant is a member, are particularly liable to this malformation, as also are the Rosaceæ, as will be seen from the following illustrations. Roses indeed often exhibit alterations of this kind as the commencement of prolification. There is also in cultivation a rose[282] called the green rose, "Rose bengale à fleurs vertes," in which all the parts of the flower are represented by leaves. One of the most remarkable features in this plant is, that the carpels have often two ovules on their margins. Now, Payer, in his "Organogénie," has shown that at a certain period of the development of the ordinary rose flower the ovary contains two collateral ovules, of which one becomes in process of time suppressed.[283] Geum coccineum has been found by Wigand with its flowers in this condition.[284]
Lindley[285] figures a very interesting illustration in Potentilla nepalensis, in which some of the flowers have their component parts leafy, in others the receptacle lengthens, till in extreme cases the whole of the floral apparatus is represented by a branch bearing a rosette of leaves.
A particular variety of the Alpine strawberry is also described as occasionally subject to this transformation. In these flowers the calyx remains normal, while all the other parts of the flower, even to the coating of the ovule, assume a leaf-like condition.[286]
Among Leguminosæ a partial leafy condition (frondescence), or a more complete degree of the same change, (chloranthy) is not infrequent, particularly in Trifolium repens. In this species the changes are so common, so various and important, that they may be alluded to in some little detail. M. Germain de Saint Pierre,[287] in commenting on the frequency with which the flowers of this plant are more or less frondescent, remarks that although all the flowers on one plant may be affected, they are all changed in the same manner, but on different specimens different degrees of transformation are found. In all the corolla and stamens are comparatively little removed from the ordinary form, the calyx and pistil, however, have a particular tendency to assume a foliar condition. The author just cited arranges the malformations of this plant under three heads, as follows: