Vegetable Teratology Part 35

*Bra.s.sica oleracea!

*Sisymbrium officinale!

Dianthus. sp Reseda Phyteuma.

Triumfetta, sp.!

Lychnis dioica.

Cerastium, sp.!

*Dictamnus Fraxinella!

Cerasus avium.

vulgaris!

*Rosa, var. cult.!

*Daucus Carota!

Heracleum, sp.

Epilobium hirsutum!

Lathyrus latifolius.

*Trifolium repens!

hybridum.

Melilotus, sp.

Medicago, sp.

Lonicera Periclymenum.

Carduus heterophyllus.

tataricus.

Scrophularia aquatica.

Symphytum officinale.

Anchusa ochroleuca.

paniculata.

*Primula sinensis!

Salix babylonica.

Hyacinthus, sp.

Tulipa, sp.

Some of the above are probably cases of mere virescence rather than of phyllody. For further ill.u.s.trations, references to authorities, &c., see under Chloranthy, Virescence, Prolification, &c.

=Phyllody of the ovules.=--Pending the settlement of the existing differences of opinion with reference to the morphological nature of the ovule and its component parts, much interest attaches to the malformations to which they are occasionally subject. Considered purely in a teratological point of view, it seems clear that the ovular coats are usually, if not always, of foliar nature, while the central nucleus is an axial organ; but if this be so there still remains the question whether the leafy coats of the ovule are processes of the carpel itself, or distinct independent formations, like the scales of a leaf-bud; as to this latter point, the evidence is at present very conflicting. Prof.

Al. Braun, who has devoted much attention to the subject, describes and figures ovules of _Nigella_ and _Adonis_, wherein the outer coat of the ovule was converted into a leafy, lobed ma.s.s, like the ordinary leaves, and these he considers to be a portion, not of the carpel, but of the ovular bud; he, however, hesitates to p.r.o.nounce an opinion on the nature of the pedicel of the ovule. In _Primulaceae_, wherein ovular changes are very common, the leafy coat of the ovule would seem, from the nature of the placenta, to be independent of the carpel. Morren, who studied the changes in the ovules of _Primula sinensis_, applied the term lepyrophylly ([Greek: lepyron], a scale) to the foliaceous condition of the testa in this plant. Unger[267] describes a series of malformations in _Primula sinensis_, consisting chiefly of reversions of the part of the flower to leaves. The carpels were entirely absent in this case, and the place of the free central placenta was occupied by a circle of leaves, sometimes bearing imperfect ovules on their edges. An instance of a similar kind has been described by A. de Candolle.[268]

In these flowers the placenta seemed to be composed of several funiculi soldered together, and bearing imperfect ovules. In other cases no traces of ovules are visible, but the funiculi are in a foliaceous condition. Moquin also alludes to a case of the same nature in _Cortusa Mathioli_, in which the funiculi bore little rounded leaves. Brongniart has described some malformations of _Primula sinensis_ in which the ovules were transformed wholly or partially into small leaves with three to five lobes.[269] Dr. Marchand[270] mentions similar changes in _Anagallis arvensis_ and _Lonicera Periclymenum_.

Cramer[271] figures ovules of _Primula sinensis_ in the form of stalked leaves, often becoming infolded at the margins, and giving origin to a small nucleus on their inner surface.

M. Ta.s.si[272] records an instance in _Symphytum officinale_ wherein the ovules were replaced by two small linear leaves arising entirely from the axis, and not from the carpels.

In most of the foregoing ill.u.s.trations the foliar portion of the ovule must have been independent of the carpel; this independence is less manifest, though probably as real in the cases now to be mentioned. In _Sinapis_ and in _Bra.s.sica oleracea_ foliaceous ovules may occasionally be seen, attached to the placenta by long stalks. No trace of the nucleus is visible in these specimens.

[Ill.u.s.tration: FIG. 140.--_Sinapis_, replum and ovules; the dotted line shows the position of the carpels.]

Griffith, in alluding to a similar case in _Sinapis_,[273] describes the ovules as foliaceous, and having their backs turned away from the axis, the raphe being next to the axis and representing the midrib the funicle corresponding to the petiole. The outer tegument of the ovule, according to Griffith, is a leaf united along its margins, but always more or less open at its apex. No inversion can, therefore, really take place in anatropous ovules, but the blade of the leaf is bent back on the funicle, with which its margins also cohere.

Caspary, in an elaborate paper on phyllomorphy occurring in _Trifolium repens_, figures foliaceous ovules springing from the edge of an open, leafy carpel. The nucleus of the ovule, in these cases, appears to originate as a little bud from the surface of the leafy ovule (figs.

141, 142).

[Ill.u.s.tration: FIG. 141.--Leafy ovules, &c., _Trifolium repens_.]

In a species of _Triumfetta_ (see p. 260), of which I examined dried specimens, the ovary was open and partly foliaceous; it bore on its infolded margins ten erect leaflets, representing so many ovules; each leaflet was conduplicate, the back being turned towards the placenta.

[Ill.u.s.tration: FIG. 142.--Leafy ovules of _Trifolium repens_, showing formation of nucleus, &c. After Caspary.]

On the other hand, there are cases in which the leafy coat of the ovule, in place of being a distinct organ, seems to originate from the margin of the carpellary leaf itself--to be, as it were, a lobule or small process of the carpel, and not an absolutely new growth. Thus, Planchon[274], from an examination of some monstrous flowers of _Drosera intermedia_, was led to the inference that the ovules are a.n.a.logous to hairs on the margins of the leaves. This acute botanist was enabled to trace all the gradations between the simple cup formed by the confluence of four glanduliferous hairs and the concave leaf and the perfect ovule.

Brongniart[275] records ovules of _Delphinium elatum_ existing in the form of marginal lobes of the carpellary leaf itself; so that each ovule corresponds to a lobe or large tooth of this leaf, the funiculus, as well as the raphe, being formed by the median nerve of the lateral lobe.

M. Clos[276] mentions a similar instance in _Aquilegia Skinneri_; and another is figured in Lindley's 'Elements of Botany,' p. 88, f. 180.

[Ill.u.s.tration: FIG. 143.--Portion of an open foliaceous carpel of _Delphinium_, with ovules on the lobules.]

Cramer[277], from an examination of several ovular malformations, as well as from the investigation of the mode of evolution of the ovules, is led to a similar conclusion with reference to the production of ovules from the modified lobes of the carpellary leaf. Figs. 143-145, copied from Cramer, show how the nucleus of the ovule is formed as a new growth from the surface of the lobes of the leaf in _Delphinium elatum_.

[Ill.u.s.tration: FIG. 144.--Section through marginal lobe of carpel (_Delphinium_), showing the nucleus (_n_).]

[Ill.u.s.tration: FIG. 145.--Section through marginal lobe of carpel, showing nucleus and tegument (_Delphinium_).]

[Ill.u.s.tration: FIG. 146.--1. Placenta of _Dianthus_, bearing ovules and carpels. 2. One of the ovaries separated.]

[Ill.u.s.tration: FIG. 147.--Ovules of _Dianthus_ pa.s.sing into carpels.]

One of the most singular instances of ovular malformation in record is that cited by the Rev. M. J. Berkeley, in the 'Gardener's Chronicle,'

September 28th, 1850, p. 612. The plant was a carnation, and its placenta bore, not only ovules, but also carpels (fig. 146), the latter originating in a perverted development of the former, so that many intermediate stages could be traced between the ordinary ovule and the ovary (fig. 147, 1, _a_, 2, _b_). Some of these carpels, thus derived from the ovules, themselves bore secondary ovules on a marginal placenta, as shown in the sections at _c_, _d_, _e_. Could such a change occur in the animal kingdom, there would be the unfertilised ovum converted into an ovary, and this again bearing Graafian vesicles! In Mr. Berkeley's carnation the change was not so great, seeing that the nucleus of the ovule was not developed, and sufficient evidence has been above given as to the foliar nature of the primine, while for a leaf to be folded up so as to form a carpel is an ordinary occurrence.

It is worthy of remark that in these foliaceous ovules there is never more than one coat, the secondine and other integuments do not make their appearance in these cases, and that very generally the change in question accompanies a similar foliaceous condition in the carpel, the margins of which are more or less disunited.

Prof. A. Braun remarks that up to this date no such change has been observed in the ovules of Monocotyledons.

=Changes in the nucleus of the ovule.=--The preceding remarks have had reference especially to the ovular coats, but it is desirable also to allude to certain points connected with the nucleus. Very frequently, when the coat of the ovule is phylloid, as before described, the nucleus is altogether wanting, though sometimes it is present as a small cellular papilla; very rarely is it to be found in its perfect state.

Occasionally the nucleus is present in the guise of a small elongated branch. Wigand cites ovular buds in every stage of progress into a branch, sometimes even bearing indications of anthers. Wydler has observed a similar occurrence in ovules of _Alliaria officinalis_, and Schimper has described and figured specimens of _Nigella damascena_ in which the outer coats of the ovule were but little changed, while the nucleus was replaced by a leafy shoot. On one of the leaves of this latter was found an imperfect ovule--an ovule on an ovule!

Fig. 148 shows a floret of a species of _Gaillardia_, in which the ovule was replaced by a leafy shoot which had made its way through a c.h.i.n.k in the ovary. In this specimen, however, there was no evidence to show whether the shoot in question was a perverted development of the nucleus, or whether it was wholly independent of the ovule.

[Ill.u.s.tration: FIG. 148.--Floret of _Gaillardia_, showing leafy shoot occupying the place of the ovule.]

From this occasional elongation of the nucleus, as well as from the foliar nature of the ovular coats, Prof. Alex. Braun arrives at the conclusion that the ovule is to be looked on as a bud, the ovular coatings, so often variable in number, representing the scales of the bud, the nucleus corresponding to the end of the axis or growing point.

Griffith had previously expressed the same opinion from his observations on malformed ovules of _Sinapis_ and _Lonicera_, while Caspary's conclusions from the foliaceous ovules of _Trifolum repens_ are somewhat similar. The latter observer considers that the funiculus, with the integuments, is the equivalent of a leaflet, the petiolule or midrib of which answers to the funiculus, and its hollow expansion to the integument. The nucleus itself is considered to be a new formation a.n.a.logous to a shoot.

M. van Tieghem's conclusion[278] from the examination, of flowers of _Tropaeolum majus_, in which the ovules were replaced by perfect peltate leaves, is that the ovules are foliar productions springing, not directly from a prolonged floral axis, as in _Primulaceae_, but from branches of the axis arising from the axils of the carpellary leaves.

Phyllody of the ovules has been met with most often in the following species:

*Aquilegia vulgaris!

Skinneri.

Delphinium cra.s.sicaule.

elatum.

dictyocarpum.

Ajacis.