Many of the instances of so-called viviparous plants, e.g., Polygonum viviparum, may be cited under this head.[112] Many species of Allium, Lilium, Saxifraga, Begonia, Achimenes, normally produce leaf-buds or bulbs in the inflorescence; so, too, leafy shoots are sometimes found in Alisma natans, Juncus uliginosus, Chlorophytum Sternbergianum, &c. As an accidental occurrence, a similar thing has been noticed in Lychnis coronaria, Phaius grandifolius, Oncidium cebolleta, Epidendrum elongatum,[113] &c. &c.
Here, too, may be mentioned those cases wherein a leaf-bud is found upon the surface of the so-called inferior ovary; generally a leaf only is found, but a leaf-bud may also originate in this situation, and in either case the inference is that the ovary is, in part at least, made of the dilated and hollowed axis. Leaves may occasionally be found in this way on the so-called calyx-tube or on the inferior ovaries of roses, pears, apples, Pereskia, Cratægus tanacetifolia, &c.
The fruits of Opuntia Salmania and of O. fragilis ('Bull. Soc. Bot. France,' vol. i, p. 306; vol. v, p. 115) have been observed to form small fruit-like branches around their summits. This circumstance is more fully treated of in the succeeding chapter relating to Heterotaxy.
Lateral floral prolification of the inflorescence.—This, which is termed by Engelmann Ecblastesis foliorum sub floralium,[114] is much the most common of all these deviations, and it is met with in every degree, from the presence of a single supernumerary flower in the axil of a bract to the existence of a small cluster or panicle of such flowers.
Fig. 53.—Lateral prolification in inflorescence of Pelargonium.
It is common in the Anemone coronaria and hortensis, also in the common scarlet Pelargonium (fig. 53). It has been frequently recorded in Poterium sanguisorba, and in Sanguisorba officinalis, and is especially common in Umbelliferæ, Dipsacaceæ, and Compositæ; a familiar illustration in the latter order is afforded by the hen-and-chicken daisy. In some species of Compositæ, indeed, it is a normal and constant occurrence, while in other cases, such as Filago germanica, usually described as proliferous, there is not, strictly speaking, any prolification, for the branching of the stalk takes place below the inflorescence, and the branches originate from the axils of ordinary leaves, not from the floral leaves or bracts. Convolvulus Sepium is very commonly subject to the production of flower-buds from the axils of the floral leaves. The several species of Plantain (Plantago) seem very liable to this and similar changes. Schlechtendal[115] gives a summary of the various kinds of malformation affecting the inflorescence in Plantago, and divides them into five groups, as follows:—1st, bracteate, wherein the inferior bracts are quite leaf-like, as is frequently seen in Plantago major. 2nd, roseate; bracts leafy in tufts or rosettes, without flowers, as in the so-called rose plantain, common in old-fashioned gardens in this country. 3rd, polystachyate; spike-branched, bearing other spikes in the axils of the bracts, as in P. lanceolata, P. maritima, &c. 4th, proliferous, where the flower-stalk bears a rosette, a spike, or a head with other rosettes. 5th, paniculate, in which the inflorescence has become a much-branched pyramidal panicle, covered with little bracts, and with very rudimentary flowers.[116] The first two groups belong rather to frondescence of the bracts; but with regard to the whole of them it will easily be surmised that intermediate forms occur, linking one group to the other, and defying exact allocation in either. Thus, in the borders of richly cultivated fields in the neighbourhood of London I have frequently gathered specimens of Plantago major with a branched spike provided with large leafy bracts, the branches of the spike being but little less in diameter than the ordinary single spike. These specimens would therefore seem to be intermediate between Schlechtendal's bracteate and polystachyate divisions. Wigand[117] also describes an anomalous specimen of Plantago major similar to those just mentioned, but having small lateral spikes in place of large ones. The instance quoted from Professor Braun would fall under the roseate section, as would also that of Kirschleger, though we are expressly told that the tuft of leaves in this last case was not developed until after the ripening of the seed-vessel. One of the characters of the roseate group, according to Schlechtendal, is the absence of flowers, but most persons who have had the opportunity of watching the growth of the rose plantain must have observed the occasional production of flowers, sometimes stalked, in the axils of the leafy bracts, and at the same time have noticed that the internodes become elongated, so that an approach is made to the ordinary spike-like form of the inflorescence. The proliferous group would include such specimens as that of P. lanceolata mentioned by Dr. Johnston,[118] wherein were several spikes, some sessile, others stalked and pendent, the whole intermixed with leaves and disposed in a rose-like manner. I have myself gathered specimens of this nature, occurring in the same plant, at Shanklin, Isle of Wight (fig. 56).
