Vegetable Teratology Part 42

=Staminody of the accessory organs of the flower.=--The scales that are met with in some plants, either as excrescences from the petals, or as imperfect representatives of stamens or other organs, are occasionally staminoid; thus the scales of _Saponaria officinalis_, of _Silene_, _Nerium Oleander_, the rays of _Pa.s.siflora_, the corona of _Narcissus_, have all been observed occasionally to bear anthers.[333] In the case of _Narcissus_ the loose spongy tissue of the corona seems to have the nearest a.n.a.logy to the anther-lobes, while the prolonged connective is more like the ordinary segments of the perianth in texture. The species in which this change may most frequently be observed are, _N. poeticus_, _N. incomparabilis_, and _N. monta.n.u.s_.

M. Bureau found in some flowers of _Antirrhinum majus_ two petal-like bodies standing up in front of, or opposite to the two petals of the upper lip,[334] and similar developments in which each of the two advent.i.tious segments are surmounted by an anther may be met with frequently. It does not follow because these organs bear anthers that they are morphologically true stamens. They are really scales, &c., taking on themselves accidentally the characters proper to stamens.

=Pistillody of the perianth.=--The pa.s.sage of the segments of the perianth into carpels has been observed frequently in _Tulipa Gesneriana_, the change in question being generally attended by a partial virescence. M. Gay is said by Moquin to have observed a flower of _Crocus nudiflorus_ in which the segments of the perianth were cleft and fringed at the same time, so that they presented the appearance of the stigmas.

[Ill.u.s.tration: FIG. 160.--Flower of tulip, allowing vertical attachment of a leaf, and also the existence of ovules on the margins of the segments of the perianth. Some of the parts are removed.]

=Pistillody of the sepals.=--In some double flowers of the garden pea communicated by Mr. Laxton, among other peculiarities was a supernumerary 5-6-leaved calyx, some of the segments of which were of a carpellary nature, and bore imperfect ovules on their margins, while at their extremities they were drawn out into styles.[335]

=Pistillody of the stamens.=--This change whereby the stamens a.s.sume more or less the appearance of pistils is more commonly met with than is the metamorphosis of the envelopes of the flower into carpels. In some cases the whole of the stamen appears to be changed, while in others it is the filament alone that is altered, the anther being deficient, or rudimentary; while, in a third cla.s.s of cases, the filament is unaffected, and the anther undergoes the change in question. In those instances in which the filament appears to be the portion most implicated, it becomes dilated so as to resemble a leaf-sheath rather than a leaf-stalk, as it does usually.

One of the most curious cases of this kind is that recorded in the 'Botanical Magazine,' (tab. 5160, f. 4) as having occurred in _Begonia frigida_ already alluded to, and in which, in the centre of a male flower, were four free ovoid ovaries alternating with as many stamens.

In the normal flowers of this plant, as is well known, the male flowers have several stamens, while in the female flowers the ovary is strictly inferior, so that, in the singular flower just described, the perianth was inferior instead of being superior, as it is usually. It should be added also that the perianth in these malformed flowers was precisely like that which occurs ordinarily in the male flowers.

[Ill.u.s.tration: FIG. 161.--Supernumerary carpels in the orange, arising from subst.i.tution of pistils for stamens.]

In some varieties of the orange, called by the French "bigarades cornues," the thalamus of the flower, which is usually short, and terminated by a glandular ring-like disc, is prolonged into a little stalk or gynoph.o.r.e, bearing a ring of supernumerary carpels. These carpels are isolated one from another, and are formed by the transformation of the filaments of the stamens.[336]

The additional carpels in the case of the apple of St. Valery, in which the petals are of a green colour, like the sepals, are by some attributed to the transformation of the stamens into carpels. These advent.i.tious carpels frequently contain imperfect ovules and form a whorl above the normal ones. (See _Pyrus dioica_ of Willdenow.)[337] A similar change occasionally happens in the stamens of _Magnolia fuscata_, while in double tulips this phenomenon is very frequent, and among them may be found all stages of transition between stamens and pistils, and many of the parts combining the characters of both.[338]

Dunal and Campdera have described flowers of _Rumex crispus_, with seven pistils, occupying the place of as many stamens.

[Ill.u.s.tration: FIG. 162.--Subst.i.tution of carpels for stamens in _Papaver_.]

In _Papaver bracteatum_ a considerable number of the stamens sometimes become developed into pistils, especially those which are nearest to the centre of the flower, and in these flowers the filaments are said to become the ovaries, while the anthers are curled so as to resemble stigmas. A similar change is not infrequent _Papaver somniferum_.

Goeppert, who found numerous instances of the kind in a field near Breslau, says the peculiarity was reproduced by seed for two years in succession.[339] Wigand ('Flora,' 1856, p. 717) has noticed among other changes the pistil of _Gentiana Amarella_ bearing two sessile anthers.

_Polemonium caeruleum_ is another plant very subject to this change.

Brongniart[340] describes a flower of this species in which the stamens were represented by a circle of carpels united to each other so as to form a sheath around the central ovary. By artificial fertilization M.

Brongniart obtained fertile seeds from the central normal ovary as well as from the surrounding metamorphosed stamens.

_Cheiranthus Cheiri_ has long been known as one of the plants most subject to this anomaly. De Candolle even mentions it in his 'Prodromus'

as a distinct variety, under the name of _gynantherus_. Brongniart (loc.

cit.) thus refers to the _Cheiranthus_:--"Sometimes these six carpellary leaves are perfectly free, and in this case they spread open, presenting two rows of ovules along their inner edges, or these edges maybe soldered together, forming a kind of follicle like that of the columbine; at other times, these staminal pistils are fused into two lateral bundles of three in each bundle, or into a single cylinder which encircles the true pistil. In a third set of cases these outer carpels are only four in number, two lateral and two antero-posterior, all fused in such a manner as to form around the normal pistil a prism-shaped sheath, with four sides presenting four parietal placentae, corresponding to the lines of junction of the staminal carpels."

In the accompanying figures (fig. 163, _a-d_) the nature of this change is ill.u.s.trated. In some of the specimens it is easy to see that the two shorter stamens undergo the change into carpels later and less perfectly than the four longer ones, and not infrequently the outer pair are altogether absent. In most of the flowers of this variety the petals are smaller and less perfectly developed than usual.[341]

[Ill.u.s.tration: FIG. 163.--_Cheiranthus Cheiri_, var. _gynantherus_. _a._ Sepals and petals removed to show carpellodic stamens. _b._ The same laid open. _c._ Transverse section. _d._ Plan of flower with four carpel-like stamens, &c.]

In _Lilium tigrinum_, some specimens of which were gathered by Mr. J.

Salter, in addition to various degrees of synanthy and other changes, some of the stamens were developed in the form of carpels, adherent by their edges so as to form an imperfect tube or sheath around the normal pistil. Fig. 164 shows one of the intermediate organs from these flowers, in which half the structure seems devoted to the formation of ovules, while the other half bears a one-celled anther. Lindley[342] has also described a case of this kind in a species of _Amaryllis_.

[Ill.u.s.tration: FIG. 164.--Structure half anther, half carpel, _Lilium_.]

In _Saxifraga cra.s.sifolia_ it sometimes happens that mixed with the stamens, and originating with them, are a number of distinct and perfectly formed carpels, wholly separated from the normal carpels, in the centre of the flower. In this particular instance there is usually no intermediate condition between the stamen and the pistil.

Guillemin[343] also describes a transformation of the stamens into carpels in _Euphorbia esula_.

When the anther is involved it may be only partially so, or almost the whole organ may be transformed. As instances of very partial change may be cited the pa.s.sage of the connective into a stigma in _Thalictrum minus_, or the pa.s.sage of the points of the anthers into imperfect styles in some species of bamboo.[344]

In _Rosa arvensis_ similar transformations have been observed of a slightly more complex character than those just mentioned, and pa.s.sing into more important changes, especially to the formation of pollen within ovules, formed on the edges of an open carpellodic anther (see p.

186).

Mr. Berkeley has recorded an a.n.a.logous case in a gourd in which the stamens bore numerous ovules (p. 200), and Baillon describes another gourd in which certain fleshy appendages surrounding the androecium were provided with ovules.[345]

Payer, in his 'Organogenie,' p. 38, mentions a stamen of _Dionaea_ bearing not only an anther, but likewise an ovule.

_Sempervivum tectorum_ and _S. montanum_, have long been noticed as being very p.r.o.ne to present this change. Mohl[346] remarks that, in the transformation of the stamens to the pistil in the common houseleek, the filament of the stamen generally preserves its form, the anthers alone undergoing change. At other times, however, the transformation takes place at the same time, both in the filament and in the anther. When the stamens are numerous some of them remain in their normal state, while others, and especially the inner ones, undergo a change. Sometimes all the stamens are changed simultaneously, while at other times some of these organs may be found in which the anther is partially filled with ovules, and partially with pollen.

In the accompanying figures (fig. 165, _a-h_) a series of intermediate stages is shown between the ordinary stamen of _Sempervivum tectorum_ and the ordinary carpel, from which it will be seen that the filament is little, if at all, affected, and that in those cases where there is a combination of the attributes of the stamen and of the pistil in the same organ the pollen is formed in the upper or inner surface of the leaf-organ, while the ovules arise from the opposite surface from the free edge, (_b_, _c_, _d_, _e_, _f_, _g_).

In a drawing made by the Rev. G. E. Smith of a malformed flower of _Primula acaulis_, and which the writer has had the opportunity of examining, the stamens are represented as detached from the corolla, and their anthers replaced by open carpels, with ovules arising, not only from their edges, but also from their surfaces, while the apex of the carpellary leaf was drawn out into a long style, terminated by a flattened spathulate stigma.

_Delphinium elatum_ is one of the plants in which this change has been most frequently noticed.[347]

[Ill.u.s.tration: Fig. 165.--_Sempervivum tecotorum._ _a._ Normal stamen.

_h._ Normal carpel. _b_, _c_, _e_, _f_, _g_. Structure partly staminal, partly carpellary. _d._ Transverse section through _c_, showing pollen internally, ovules externally.]

In willows the change of pistils into staminal organs has been frequently observed. In _Salix babylonica_ Prof. Schnizlein has described various transition stages between the carpels and the stamens, and in one instance, in addition to this change, a perfect cup-shaped perianth was present, as happens normally in _Populus_[348]. Mr. Lowe also records the conversion of stamens into ovaries in _Salix Andersoniana_, and this by every conceivable intermediate gradation.[349]

The following list will serve to show what plants are most subject to this anomaly. It is difficult to draw any accurate inference from this enumeration, but attention may be called to the frequency of this occurrence in certain plants, such as the _Sempervivum_, the wallflower, the poppy, and the heath. Why these plants should specially be subject to these changes cannot be at present stated.

By the student of animal physiology such a change as above described--equivalent to the subst.i.tution of an ovary or a uterus for a testis--would be looked on as next to impossible; the simpler and less specialised structure of plants renders such a change in them far more easy of comprehension.

Thalictrum minus.

Delphinium elatum.

Magnolia fuscata.

Bocconia cordata.

*Papaver bracteatum!

* somniferum!

nudicaule.

Dionaea muscipula!

Barbarea vulgaris.

*Cheiranthus Cheiri!

Cochlearia Armoracia.

Tropaeolum majus.

Citrus Aurantium.

*Sempervivum tectorum!

montanum.

Begonia frigida!

Cuc.u.mis, sp.

Cucurbita Pepo.

Pyrus Malus.

Rosa arvensis!

Saxifraga cra.s.sifolia!

Myrtus, sp.

Campanula rapunculoides.

Polemonium caeruleum.

Gentiana Amarella.

*Erica Tetralix.

Stachys germanica.

Primula acaulis.