Lonicera xylosteum.

Periclymenum.

Gentiana Amarella.

Gilia glomeriflora.

*Symphytum officinale.

Petunia violacea!

Verbasc.u.m, sp.

Antirrhinum majus!

Stachys sylvatica.

*Anagallis phoenicea?

Primula sinensis!

Polemonium coeruleum.

See Moquin-Tandon, 'El. Terat. Veg.,' p. 203. Engelmann, 'De Anthol.,' -- 38 _et seq._; tab. ii, figs. 8-14, _Gilia_; tab. v, 23-26, _Senecio_; tab. v, f. 1-13, _Torilis_; tab. iv, f. 3, _Erysimum_. 'Bull. Soc. Bot. Fr.,' vol. ii, 1855, p. 479, _Primula sinensis_. Giraud, 'Edinb. Phil. Magazine,' 1839, _Antirrhinum_. Jaeger, 'Act. Acad. Caes. Nat. Cur.,' vol. xiii, 2, p. 1, tab. xli, _Tropaeolum_. Bischoff, 'Lehrbuch,' 11, 2, p.

27, _note_, _Tropaeolum_. Fresenius, 'Mus. Senkenb.,' ii, 35, tab. 4, fig. 5, _Actaea_. See also succeeding paragraphs and sections in Chloranthy, Virescence, &c.

=Phyllody of the stamens= happens less frequently than the corresponding condition in the neighbouring organs. The structure of the anther is so much removed from that of the leaf, that the change of the stamen from its ordinary condition to that of a leaf must be regarded as indicating a greater degree of perverted development than that which occurs in those cases where less highly differentiated organs, such as the sepals, petals, and pistils, are thus altered.[260]

In all cases it is desirable to ascertain, if possible, what parts of the stamen are thus transformed. In some Petunias the filaments are unchanged, but in place of the anther is a small lamina, representing precisely the blade of an ordinary leaf. Sometimes the connective only is replaced by a leaf. One of the most interesting cases of this kind that has fallen under the writer's observation was in _Euphorbia geniculata_, in which, in addition to other changes mentioned under prolification of the inflorescence, some of the stamens were partly frondescent, half the anther being perfect, the other half leaf-like.

Another filament bore just above the usual joint three leaflets, two lateral ones, somewhat conduplicate, and a third central one, half anther, half leaflet.

[Ill.u.s.tration: FIG. 134.--Flower of a _Petunia_, opened to show the stamens partially replaced by stalked leaves.]

In the case of frondescent flowers of _Tropaeolum majus_ the stamens are usually absent or atrophied, but in other instances the filament is present as usual, representing the stalk of the leaf, and surmounted by a small lamina, but this latter, in place of being nearly flat, is pinched up in the centre from back to front, and surmounted by a two-lobed anther, so that the general appearance of the whole structure is that of a central anther, supported at the base on each side by two concave leaf-lobes, or it might be compared with a three-lobed leaf, the terminal lobe represented by the anther.

In _Jatropha Pohliana_, Mull. (_Adenorophium luxurians_, Pohl.), a singular condition has been observed by M. Muller (Argov.). In this flower the anther, in place of being represented by the flat blade of a single leaf, had the appearance as if two such blades were present and coherent one with the other by their midribs, along their upper or inner surfaces, which were directed towards the centre of the flower (fig.

136), thus resembling the cases of adhesion of leaves by their surfaces already referred to (p. 33). In other cases, in the same plant, the anther appeared as if formed by two collateral leaves, the faces looking towards the circ.u.mference of the flower, and their margins so folded together as to represent an open anther lobe (fig. 135). These cases are apparently due, not to the formation and adhesion of two leaves, but rather to the exuberant development of one leaf into two blades.[261]

The bearings of these and other similar malformations on the morphology of the anther are alluded to under the head of petalody of the anther.

[Ill.u.s.tration: FIG. 135.--Phylloid anther of _Jatropha_, after Muller (Arg.).]

[Ill.u.s.tration: FIG. 136.--Leaf-like anther of _Jatropha Pohliana_, after Muller.]

Phyllody of the stamens has been most often observed in the following plants:

Anemone nemorosa.

coronaria.

Delphinium cra.s.sicaule.

Nymphaea dentata.

Tropaeolum majus!

Dictamnus albus.

*Trifolium repens!

Torilis anthriscus.

Heracleum Sphondylium.

Daucus Carota Epilobium hirsutum!

*Rosa, var. cult.!

Lonicera Periclymenum.

Anagallis arvensis.

Primula sinensis!

Petunia, var. cult.

Jatropha Pohliana.

Euphorbia goniculata.

In addition to the foregoing there are very numerous instances of similar subst.i.tution in chloranthic flowers. In the above list only those cases are given wherein the leafy change is confined to the stamens, or, at least, to a few only of the other parts of the flower.

=Phyllody of the pistils.=[262]--This is of more common occurrence than is the corresponding change in the case of the stamens. It is of interest, as it sometimes serves to ill.u.s.trate the morphological nature of the pistil. Of this the double-flowering cherry is a well-known ill.u.s.tration, the pistil being here represented by two small foliar laminae, whose midribs are prolonged with a short style, terminated by an imperfect stigma. It is usually the basal portion of the pistil, the ovary, which is thus specially affected, the margins being also often disunited so as to expose the ovules. These latter organs may be absent or they may themselves be the subjects of foliaceous development.

Moquin[263] relates having found in the neighbourhood of Montpellier a flower of a tulip the ovary of which was represented by true leaves, which bore on their margins the ovules, and thus presented a striking a.n.a.logy with the carpels of those Sterculias, like _S. platanifolia_, which are foliaceous in texture and open very early in the course of their development. A similar occurrence has also been frequently noticed in the Columbine and also in _Cruciferae_ and _Umbelliferae_. M.

Germain de St. Pierre mentions an instance wherein the carpels of _Salix Babylonica_ were converted into two leaves, provided with stipules. All the flowers of the catkins were similarly changed, so that it became permanent, and resembled a branch.

[Ill.u.s.tration: FIG. 137.--Rose, in which the axial portion of the flower was elongated and the carpels were more or less replaced by leaves.]

Subst.i.tutions of this kind form the green "eyes" or centres of certain varieties of _Ranunculus_ and _Anemone_.

In proliferous roses, or in cases where the central axis of the flower is prolonged, it frequently happens that the pistils are more or less replaced by leaves. Fig. 137, from a specimen of Dr. Bell Salter's, given in the 'Gardeners' Chronicle,' shows the pa.s.sage, from below upwards, of the ordinary carpels to perfect leaves; the so-called calyx-tube being completely deficient and the ovaries entirely superior.

Like most similar specimens, this one bears out the notion that what is called the calyx-tube in roses is really an expansion and dilatation of the top of the flower-stalk.

[Ill.u.s.tration: FIG. 138.--Cuc.u.mber with leaf attached.]

Fig. 138, for which I am indebted to Mr. S. J. Salter, represents a very singular conformation in the cuc.u.mber, described by that gentleman in 'Henfrey's Botanical Gazette,' i, p. 208, and considered by him to be due to the foliaceous condition of one of the three carpels of which the fruit is composed. The portion near the peduncle was binary, while the distal extremity of the fruit was ternary. The main difficulties attending the acceptance of this explanation reside in the peculiar reversed position of the leaf, and in the fact that the fruit of the _Cucurbitaceae_ is probably of axial nature, the dilated and succulent end of the peduncle adhering to and usually concealing the carpels; in some cases, however, these latter project beyond the axial portion, leaving no doubt as to the true nature of the structure in these particular instances.

Admitting the axial nature of the fruit, it might be supposed that in Mr. Salter's cuc.u.mber an advent.i.tious leaf had been given off from the axis, but even on that supposition the reversed position offers a difficulty, and there still remains to be explained the fact that the proximal part of the fruit was binary in its const.i.tution, the distal end ternary.

M. Norman[264] mentions a case wherein the carpels of _Anchusa ochroleuca_ were replaced by two leaves; from this he draws the inference that the pistil of borages and l.a.b.i.ates is really composed of two leaves, placed fore and aft, the margins of the leaves being congenitally fused. This tallies well with the account given of the development of these plants by Payer, Germain de St. Pierre, and others.

In an Indian species of _Triumfetta_, not only were the petals virescent, but the ovary also was much enlarged, and in some flowers it was divided half way down into five lanceolate leaves (fig. 139), the sepals and stamens being in their normal condition.

In the preceding instances the foliaceous condition has pervaded the entire pistil, or at any rate the basal portion or ovary, and it may be noticed that the ovary is thus shown to consist in some cases of the sheath of the leaf, as in _Aquilegia_; in other cases of the blade, as in _Cerasus_, _Daucus_, &c.

[Ill.u.s.tration: FIG. 139.--Flower of _Triumfetta_, sp., carpels represented by five leaves.]

There are cases, however, in which a part only of the pistillary structure thus becomes foliaceous. Linnaeus, 'Prolepsis,' -- 9, mentions some flowers of _Carduus heterophyllus_ and _C. tataricus_ in which the style had grown into two green leaflets, and in which the calyx and corolla were also leaf-like. A very singular instance is recorded by Baillon,[265] wherein the pistil of _Trifolium repens_ consisted of three carpels, either separate, or combined so as to form a one-celled ovary with three parietal, pluri-ovulate placentae; the ovary in these flowers was formed of the basal vaginiform part of the leaf; the three styles were formed by the petioles, while the stigmas were represented by trifoliolate leaves. The back of the leaf in these cases is usually directed away from the centre of the flower. When this change occurs it is commonly attended by an increased number of parts, as in the trefoil just mentioned, or in the double cherry, where usually two foliaceous carpels may be met with, and sometimes more.

The change is also of interest when it affects such orders as the _Umbelliferae_, which have their ovaries inferior under ordinary circ.u.mstances; but when these organs a.s.sume a leafy condition they become superior also, _i.e._ they are detached from the calyx.

As regards the position of the ovules in these foliaceous pistils, they may be placed, as in _Aquilegia_, _Delphinium_, &c., on the edges of the carpel or on the surface, as in some flowers of _Ranunculus repens_ and _R. Ficaria_. A similar position of the ovules is recorded in the case of the vine (_Vitis_), where the pistil consisted of leaves bearing the ovules on their inner surface.[266] The supposed causes of this and other similar malformations are alluded to under the head of chloranthy, but it may be here remarked that semi-double flowers, fertilised by the pollen of similar flowers, are said to produce flowers with a centre of small green leaves, this central tuft resulting from the expansion and frondescence of the pistils.

As this condition rarely occurs without corresponding changes in other parts of the flower, further remarks on this subject will be found in the chapter relating to Chloranthy.

Phyllody of the pistil has been most frequently recorded in the following plants:

Paeonia officinalis.

Ranunculus repens!

*Aquilegia vulgaris!

Delphinium elatum.

cra.s.sicaule.

Ajacis.

amaenum.

Nymphaea dentata.

Sinapis arvensis!

Diplotaxis tenuifolia.