Chapter 18

Anemone!Ranunculus!Aconitum!Raphanus.Bunias.Saponaria.Dianthus!Pelargonium!Hibiscus.Fuchsia.Sarothamnus!Lotus!Ulex!Prunus!Trifolium.Œnanthe and Umbellif. pl.!Sambucus!Bryonia.Campanula.Solanum.Veronica.Cyclamen!Primula!Anagallis!Plumbago.Jasminum.Syringa!Tradescantia.Iris.Tigridia.Narcissus.Tulipa.Convallaria!Paris!Hyacinthus!Allium!Ornithogalum.Orchideæ, sp. pl.!

For other illustrations see multiplication of whorls, petalody; see also Moquin, loc. cit., p. 350. Engelmann, loc. cit., p. 20, § 18. Cramer, loc. cit., p. 25.

Polyphylly of the andrœcium.—An increased number of stamens frequently accompanies the corresponding alterations in other whorls, and seems, if anything, to be more frequent among monocotyledonous plants than among dicotyledonous ones; thus, we occasionally find tetramerous flowers inCrocus,Hyacinthus,Tulipa,Iris,Tigridia, &c., and more rarely inYucca(Y. flexilis[401]).

The increased number of stamens in a single whorl may result from a development of organs usually suppressed, and constitute a form of regular peloria as inLinaria, wherein a fifth stamen is occasionally met with. Among normally didynamous plants such numerical restitution, so to speak, is not unusual; thus, inVeronicafour and five stamens occur. Fresenius has seen five stamens inLamium,Mentha,Chelone;[402]Bentham inMelittis, and other instances are cited under the head of peloria. Chorisis may also serve to account for some of these cases; thus, Eichler[403]figures a flower ofMatthiola annuawith five long stamens instead of four; one of the long pairs of stamens has here undergone a greater degree of repetition than usual. De Candolle[404]cites and figures a curious form ofCapsella Bursa-pastorissent him by Jacquin, and which was to some extent reproduced by seed. In the flowers of this variety there were no petals, but ten stamens; hence De Candolle inferred that the petals were here replaced by stamens, but Moquin[405]objects, and with justice, to this view, as the ten stamens are all on the same line; he considers the additional stamens to be the result of chorisis. Buchenau[406]mentions the presenceof seven stamens in another Crucifer,Ionopsidium acaule. Here the supernumerary organ was placed between two of the long stamens. The effect of chorisis in producing an augmentation of parts is well seen in some plants that have some of their flowers provided with staminodes or abortive stamens, and others with clusters or phalanges of perfect stamens. Thus, in the female flowers ofLiquidambarthere are five small staminodes without anthers, whereas in the male flower the stamens are numerous and grouped together in phalanges, so that the relation of simple to compound stamens is in this case readily seen, as also in manyMalvaceæ,Sterculiaceæ,Byttneriaceæ,Tiliaceæ, andMyrtaceæ. It is probably the idea of splitting or dilamination involved in the word chorisis that has led many English botanists to hesitate about accepting the notion. Had they looked upon the process as identical with that by which a branched inflorescence replaces an unbranched one, or a compound leaf takes the place of a simple one, the objections would not have been raised with such force. The process consists, in most cases, not so much in actual cleavage of a pre-existing organ as in the development of new-growing points from the old ones.

An illustration given by Moquin from Dunal[407]goes far to support the notion here adopted. The majority of the stamens of laurels (Laurus) have, says M. Dunal, on each side of the base of their filaments a small glandular bifid appendage; these excrescences are liable to be changed into small stamens. The male flowers have a four-leaved calyx, and sometimes eight stamens, each with two glands, four in one row, opposite to the sepals, four in a second series alternating with the first. More generally two of the stamens are destitute of glands, but have in their place a perfectly developed stamen, so that in these latter flowers there are twelve stamens.

M. Clos[408]mentions a flower of rue (Ruta) wherein there were two stamens joined together below and placed in front of a petal, as inPeganum.

Buchenau[409]mentions a flower ofLotus uliginosusin which there were eleven stamens, namely, two free and nine monadelphous; and Hildebrand describes an analogous increase in a flower ofSarothamnus scopariusin which, in conjunction with a seven-toothed calyx, there were two carinas and fourteen stamens. It would seem probable in this case that there was a coalescence of two flowers at an early date and consequent suppression of some of the parts of the flower. Whether this was the case or not in this particular illustration, it is nevertheless certain that many of the recorded instances of increased number in the organs of a flower are really the results of a fusion of two or more flowers, though frequently in the adult state but few traces of the coalescence are to be seen.

Polyphylly of the gynœcium.—Moquin[410]remarks that, as the pistils are, generally speaking, more or less subject to pressure, owing to their central position, and it may be added owing to their later development, than the other parts of the flower, they are more subject to suppression than to multiplication; nevertheless, augmentation in the number of carpels does occasionally take place, especially when the other parts of the flower are also augmented in number. Sometimes this increase in the number of carpels is due to pure multiplication, without any other change. At other times the increase is due to a substitution of stamens or other organs for carpels (see Substitutions). In other cases the augmentation seems to be due to the development of parts usually suppressed; for instance, inAntirrhinum, where there are usually only two carpelspresent, but where, under peculiar circumstances, five may be found—thus rendering the symmetry complete.[411]InPapilionaceæ, wherein usually only one carpel is developed, we occasionally find two, or even more, as inWistaria,Gleditschia,Trifolium, &c. InPrunusandAmygdalusfrom two to five carpels are occasionally to be found,[412]inMimosafive, inUmbelliferæthree to five; in some composites,e.g.Spilanthes, five carpels have also been noticed; inCruciferæthree and four, in grasses three.[413]The double cocoa-nut affords an illustration of the development of two carpels out of three, one only generally arriving at perfection. Triple nuts (Corylus) also owe their peculiarity to the equal development of all three carpels which exist in the original flower, but of which, under ordinary circumstances, two become abortive. It is necessary, however, to distinguish these cases from those in which two embryos are developed in one seed.

The following list may serve to show in what genera this change has been most frequently noticed, and it may be said in general terms thatCruciferæ,Umbelliferæ, andLiliaceæ, are the orders most frequently affected. Cases of peloria are not included in the subjoined list.

Nigella.Aquilegia.Pæonia!Delphinium!Iberis.Diplotaxis.Lunaria.Ricotiana.Octadenia.Draba!Lepidium.*Cheiranthus!Dianthus.Brassica!Parnassia.*Acer!Ptelea.Citrus!Philadelphus.Prunus!Amygdalus!Cratægus!Fuchsia!Trapa!Cassia.Cercis.Medicago.*Phaseolus!Wistaria.Gleditschia.Affonsea.Trifolium!Archidendron.Mimosa.Robinia.Diphaca.Cœsalpinia.Vicia.Anthyllis.Cucurbita.Passiflora!Sambucus!*Œnanthe!Daucus!Angelica!Heracleum!Silaus.Carum.Thysselinum.Campanula!Spilanthes.Chrysanthemum.Anagallis.Primula!Fraxinus!Lycium.Cobæa.Datura!Solanum!Sesamum.Sideritis.Coleus.Veronica!*Digitalis!Antirrhinum!Linaria.Gloxinia!Symphytum.Anchusa.Polygonum.Euphorbia.Cneorum.Mercurialis!Chenopodium.Suæda.Beta.Corylus!Lambertia.Cocos!Tigridia.Tulipa!Iris!Narcissus!Allium!Ornithogalum.Gagea!Tradescantia!Schœnodon.Bambuseæ.

A few additional references may here be given to papers where an increased number of carpels is described:—Engelmann, 'De Antholys,' § 17, p. 19. Bernhardi, 'Flora,' 1838, p. 129. Schkuhr., 'Bot. Handb.,' t. 179. Godron, 'Ann. Sc. Nat.,' ser. 5, vol. ii, p. 280, tab. xviii,pluricarpellary Crucifers. Weber, 'Verhandl. Nat. Hist. Vereins. Rhein. Pruss.,' &c., 1860,Cerasus, &c., &c. Baillon, 'Adansonia,' iv, p. 71,Trifolium. Schlechtendal, 'Bot. Zeit.,' xv, p. 67,Datura, three-celled fruit; 'Bot. Zeit.,' xiii, p. 823,Phaseolus, double pistil—a common case. Cramer, 'Bildungsabweich,' p. 99, reference to several leguminous plants with polycarpellary pistils. Munro, Gen., 'Linn. Trans.,' vol. xxvi, p. 26,Bambuseæ. Alph. de Candolle, 'Neue Denkschrift,'Cheiranthus. Schimper, 'Flora,' 1829, ii, p. 433. Wigand, 'Bot. Untersuch.' Fleischer, 'Missbild. Cultur Pfl.' Cramer, 'Bildungsabweich,' p. 65,Umbelliferæ.

Polyphylly of the flower in general.—Although, for the sake of convenience, multiplication has here been treated of as it affects the members of individual whorls of the flower, yet it must be remembered that, in general, the augmentation is not confined to one whorl, but affects several; thus, if the sepals are increased, thepetals are likely to be so likewise, and so forth. One of the most curious illustrations of this is that recorded by Mr. Berkeley[414]in a plum, wherein there was an increased number of sepals, a corresponding augmentation in the petals, while the pistil was composed of two and sometimes three carpels distinct from the calyx and from each other. In the flowers there did not appear to be any definite relation in the position of the parts either with reference one to another or to the axis.

Fig.186.—Plum. Increased number of parts in the calycine, corolline, and carpellary whorls respectively.

InPrimulaceæthis general augmentation has been frequently noticed.[415]

AmongOrchideæthe instance related by Dr. Seubert is worth alluding to here. This botanist observed and figured a flower ofOrchis palustriswith tetramerous arrangement of parts, that is to say there werefour outer segments to the perianth, four petals, of which two were lip-like, four stamens, three of which were rudimentary, and an ovary with four parietal placentæ.[416]

The following list will serve to show in what plants this general augmentation of parts has been observed most frequently:

Ranunculus.Clematis!Delphinium.Brassica!Ruta.Acer!Prunus!Rosa!Rubus.Philadelphus!Chrysosplenium.Umbelliferæ, sp. pl.!*Fuchsia!Œnothera.Adoxa.Bryonia.Cucumis!Campanula!Sambucus!*Primula!Anagallis!Lycium.Solanum.Symphytum.Syringa!Linaria.Chenopodium.*Paris!Convallaria!Allium.*Lilium!*Tulipa!Ornithogalum.*Gagea!Tradescantia!Orchideæ, sp. pl.!

Increased number of ovules or seeds.—This appears not to be of very frequent occurrence, at least in those plants where the number of these organs is normally small; where, as inPrimula, the ovules and seeds are produced in large quantities, it is not practicable to ascertain whether the number be augmented or not in any particular case. Very probably, the attachment or source of origin of the ovules determines, in some measure, their number. Thus, in the case of marginal placentation the number must be limited by the narrow space from which they proceed, whereas in parietal and free central placentation the ovules are generally numerous. In the latter case, however, it will be remembered that solitary ovules are not rare. An increased number of ovules is generally remarked in conjunction with some other change, such as a foliaceouscondition of the carpel, in which the margins are disunited. In such cases the ovules may occupy the margin or may be placed a short distance within it, as in the case of some open carpels ofRanunculus Ficaria,[417]and in which two ovules were borne in shallow depressions on the upper or inner surface of the open carpel and supplied with vascular cords from the central bundle or midrib. The outer coating of the ovule here contained barred or spiral fusiform vessels derived from the source just indicated.

In the very common cases where the pistil ofTrifolium repensbecomes foliaceous (see Frondescence), the outer ovules are generally two or more instead of being solitary. So, also, in the Rose with polliniferous ovules (see p. 274). AmongUmbelliferæaffected with frondescence of the pistil a similar increase in the number of ovules takes place. It will be borne in mind that in most, if not all, these cases the structure of the ovule is itself imperfect.[418]

What are called in popular parlance double almonds or double nuts (Corylus) are cases where two seeds are developed in place of one.

In the 'Revue Horticole,' 1867, p. 382, mention is made of a bush which produces these double nuts each year—in fact, it never produces any single-seeded fruit. The plant was a chance seedling, perhaps itself the offspring of a double-seeded parent. It would be interesting to observe if the character be retained by the original plant, and whether it can be perpetuated by seed or by grafting.

It is necessary to distinguish in the case of the nut between additional seeds or ovules, as just described, and the double, triple, or fourfold nuts that are occasionally met with, and which are the result either of actual multiplication of the carpels or of the continued development of some of the carpels which, under ordinarycircumstances cease to grow (seeante, p. 364). In the case of a ripe nut with two seeds it might be impossible to tell whether the adventitious seed were the product of multiplication, or whether it belonged, in the first instance, to the same carpel as that producing the fellow-seed, or to a different and now obliterated ovary. In all probability, however, the second seed would be accounted for by the development of two seeds in one carpellary cavity.

There is still another condition occasionally met with in the almond, and which must be discriminated from the more common multiplication of the seed, and which is the multiplication of the embryos within the seed, and which furnishes the subject of the succeeding paragraph.

Increased number of embryos.—A ripe seed usually contains but a single embryo, although in the ovular state preparation is commonly made for more; and, indeed, in certain natural orders plurality of embryos in the same seed does occur, as inCycadeæandConiferæ. In the seeds of the orange (Citrus), in those of someEuphorbiaceæ, &c., there are frequently two or more additional embryos. A similar occurrence has been recorded in the mango, for a specimen of which I am indebted to the Rev. Mr. Parish, of Moulmein.[419]

Plurality of embryos has also been observed in—

Raphanus sativus.*Citrus Aurantium!Diosma, sp.Hypericum perforatum.Triphasia aurantiaca.*Æsculus Hippocastanum!Euonymus latifolius.*Mangifera indica!Eugenia Jambos.Amygdalus vulgaris!Vicia, sp.Cassia, sp.*Viscum album!Daucus Carota.Ardisia serrulata!Cynanchum nigrum.fuscatum.Euphorbia rosea.Cœlebogyne ilicifolia.Allium fragrans.Funckia, sp.Carex maritima.Zea Mays.

See Schauer's translation of Moquin-Tandon, 'El. Terat. Veget.,' p. 245, adnot., and 'Al. Braun Polyembryonie.'

Increased number of the cotyledons.—Although the presence of one or of two cotyledons in the embryo is generally accepted as a valuable means of separating flowering plants into two primary groups, yet, like all other means of discrimination, it occasionally fails, and, indeed, almost always requires to be taken in conjunction with some other character. There are cases among flowering plants where the embryo is homogeneous in its structure, there are others in which the number of the cotyledons is more than two. Thus, in some seeds ofCola acuminatathe cotyledons vary in number from two to five. I have not been able to ascertain precisely whether this multiplication of the cotyledons is characteristic of all the seeds of particular trees, or whether some only are thus affected. Some fruits that I examined bore out the latter view, as in the same pod were seeds with two, three, and four cotyledons respectively.

I have also seen three cotyledons present in embryo-plants ofCorrea,Cratægus Oxyacantha,Dianthus sinensis,Daucus Carota,Cerasus Lauro-cerasus. De Candolle alludes to a case of the kind in the bean, and figures a species ofSolanumwith three cotyledons.[420]Jaeger alludes to a similar instance inApium Petroselinum;[421]Ehrenberg to one in the marigold (Calendula);[422]Reinsch to an analogous appearance in the beech (Fagus), associated with a union of the margins of two out of the three cotyledons, and of those of two out of the three leaves next adjacent.[423]This fusion seems frequently to accompany increase in the number of cotyledons. It was so in theCorrea, and in theCratæguspreviously mentioned. Some of these cases may be accounted for by chorisis or by a cleavage of the original cotyledons, as happens, according to Duchartre,[424]in someConiferæ, which he considers to be improperly termed polycotyledonous. Whether this holds good in the Loranths, where (Nuytsia,Psittacanthus) an appearance of polycotyledony exists, is not stated. In the case of the rue (Ruta) figured by M. A. de Jussieu[425]this splitting of one cotyledon into two is sufficiently evident, as is also the case in the sycamore (Acer pseudo-platanus), seedlings of which may often be met with divided cotyledons.

In other instances a fusion of two embryo plants may give rise to a similar appearance, as in theEuphorbiaandSinapisfound by M. Alph. de Candolle (seeante, p. 56).

Pleiotaxy or multiplication of whorls.—In the preceding section notice has been taken of the increased number of parts in a single whorl, but an augmentation of the number of distinct whorls is still more frequently met with. Many of the so-called double flowers owe their peculiarity to this condition. The distinction between the two modes in which the parts of the flower are increased in number has been pointed out by Engelmann, Moquin, and others, and the two seem to require distinctive epithets; hence the application of the terms polyphylly and pleiotaxy, as here proposed.

Pleiotaxy in the bracts.—An increase in the number of bracts has been met with very constantly in a species ofMæsa, and in a peculiar variety of carnation, called the wheat-ear carnation.[426]In some of these cases the increase in the number of bracts is attended by a corresponding suppression in the other parts of the flower. Such a condition has been frequently met with inGentiana Amarella, where the bracts are increased innumber, coloured purple, and destitute of any true floral organs. A similar condition exists in some varieties ofPlantago major(var.paniculata), as has been previously stated, p. 109.

Fig.187.—Wheat-ear carnation. The appearance is due to the multiplication of the bracts and the suppression of the other parts of the flower.

It has been noticed also in the common pea,Pisum sativum, and M. Lortet[427]records a case of the kind inErica multiflora, the flowers of which, under ordinary circumstances, are arranged in clusters, but in this case the pedicels were more closely crowded thanusual, and were covered for their whole length with small rose-coloured bracts arranged in irregular whorls, the upper ones sometimes enclosing imperfect flowers. In the 'Gardeners' Chronicle,' 1865, p. 769, is figured a corresponding instance ofDelphinium Consolida, in which the bracts were greatly increased in number, petaloid, and, at the same time, the central organs of the flower were wholly wanting.

Fig.188.—Delphinium Consolida. Multiplication of bracts at the expense of the other parts of the flower.

Fig.189.—Multiplication of bracts, &c.,Pelargonium.

In flowers ofPelargoniummay occasionally be seen a repetition of the whorls of bracts, in conjunction with suppression and diminished size of some of the other portions of the flower (fig. 189).

The common foxglove (Digitalis purpurea) has likewise occasionally been observed subject to a similar malformation.

Cornus masandC. suecicasometimes show a triple involucre.[428]Irmish[429]records an analogous case inAnemone Hepatica, wherein the involucre was doubled. Similar augmentation occurs in cultivated Anemone. In addition to the plants already mentioned, Engelmann[430]mentions as having produced bracts in unwonted numbers,Lythrum Salicaria,Plantago major,Veronica spicata,Echium vulgare,Melilotus arvensis, andRubus fruticosus.

It must here be remarked that this great number of the bracts occurs naturally in such plants asGodoya, in which the bracts, or, as some consider them, the segments of the calyx, are very numerous, and arranged in several overlapping segments.

In some of the cultivated double varieties ofNigellathe finely divided involucral bracts are repeated over and over again, but on a diminished scale, to the exclusion of all the other parts of the flower.

Pleiotaxy or repetition of the calyx.—The true calyx is very seldom affected in this manner, unless such organs as the epicalyx of mallows,Potentilla, &c., be considered as really parts of the calyx.

InLinaria vulgarisRœper observed a calyx consisting of a double series, each of five sepals, in conjunction with other changes.[431]It is also common in double columbines, delphiniums, nigellas, &c.

In the 'Revue Horticole,' 1867, p. 71, fig. 9, is described and figured by M. B. Verlot a curious variety of vine grown for years in the Botanic Garden at Grenoble, under the name of the double-flowered vine. The place of the flower is occupied by a large number of successive whorls of sepals disposed in regular order, and without any trace of the other portions of the flower. It is, in fact, more like a leaf-bud than aflower. The outermost whorls of this flower open at the time when the ordinary flowers of vines do; the second series are gradually produced, and expand about the time when the ovaries of the normal flowers begin to swell; a third series then gradually forms, and so on, until frost puts a stop to the growth. This malformation, it appears, is produced annually in certain varieties of vine, and may be perpetuated by cuttings.

The flower of the St. Valèry apple, already alluded to under the head of sepalody, might equally well be placed here. It is not very material whether the second whorl of organs be regarded as a repetition of the calyx or as a row of petals in the guise of sepals.

Engelmann[432]cites the following plants as occasionally presenting a repetition of the calyx, in most cases with a suppression of the other floral whorls:—Stachys lanata,Myosotis palustris,Veronica media,Aquilegia vulgaris,Nigella damascena,Campanula rapunculoides.

Pleiotaxy in the perianth.—Increase in the number of whorls in the perianth is common in lilies, narcissus, hyacinths, &c. It may be also met with occasionally among orchids. The lily of the valley (Convallaria maialis) seems also to be particularly subject to an increase in the number of parts of which its perianth consists, the augmentation being due partly to repetition or pleiotaxy, partly to the substitution of petaloid segments for stamens and pistils.[433]

In this place may also be mentioned the curious deviation from the ordinary structure occasionally met with inLilium candidum, and known in English gardens as the double white lily. In this case there are no true flowers, but a large number of petal-like segmentsdisposed in an irregular spiral manner at the extremity of the stem, some of the uppermost being occasionally verticillate.[434]

Fig. 190.—Double white lily. Multiplication of perianth-segments and other changes.

Pleiotaxy of the corolla.—With reference to double flowers, it was remarked by Linné that polypetalous flowers were, as he said, multiplied, while monopetalous flowers were duplicated, or triplicated, as the case may be,[435]a statement that is true in the main, though itrequires modification. In the case of polypetalous, or rather dialypetalous flowers, the petals may be very largely increased by multiplication, as in roses, anemones, pinks, &c. In the last-named genus the number is often so much increased that the calyx splits from the tension exercised on it by the increasing mass within. This multiplication may happen without any metamorphy or substitution of petals for stamens, though, in the majority of cases, it is associated with such a change. It is curious to observe in some of these flowers that the total number of parts is not greatly increased; thus, in some of the double-floweredLeguminosæ, such asUlex europæusandLotus corniculatus, the petals are repeated once or twice, the stamens are petalodic, but reduced in number, while the carpels are usually entirely wanting. Thus, owing to the diminished number of parts in the inner whorls of the flower, these very double-looking blooms do not contain any greatly increased number of parts.[436]

Flowers that, under ordinary circumstances, are gamopetalous, become, in some instances, multiplied by the formation of additional segments, just as in the case of polypetalous corollas; but in these cases the corollas become polypetalous, their petals do not cohere one with another. Among double flowers of this character may be mentionedCampanula rotundifolia,Gardeniasp.,Nerium Oleander,Serissasp.,Arbutus Unedo, &c. The change is associated with petalody of the stamens and pistils.

A more frequent change among the monopetalous orders is the duplication or triplication of the corolla, in consequence of which there appear to be a series of corollas enclosed one within the other, the lobes of which generally alternate with one another, but which sometimes are superposed. This happens occasionally in the primrose (Primula acaulis), and constitutes the variety called by the gardeners "hose in hose."

The same condition occurs frequently in some species ofDaturaandCampanula.

Fig.191.—Campanula rotundifolia. "Double flowers" resulting from dialysis and multiplication of the petals.

InAntirrhinum majusdouble flowers of this character sometimes occur; the outermost corolla is normal, the succeeding ones usually have their petals separate one from the other; the stamens are sometimes present, sometimes absent, and at other times petalodic. Similar occurrences may be met with in labiates and jasmines, and inErica hyemalis.

Mr. W. B. Hemsley has kindly furnished me with flowers of a similar kind occurring in wild specimens ofEpacris impressa,[437]and there are analogous phenomena in the common honeysuckle (Lonicera Periclymenum), in which three corollas and no stamens often occur.

This duplication may either be accounted for on the theory of chorisis above alluded to, or by supposing that the extra corolline whorl is due to a series of confluent petalodic stamens; that the latter is the true explanation, in certain cases at least, is shown by some flowers ofDatura fastuosa, in which the second corolla was partially staminal in its appearance, and bore nearly perfect anthers, in addition to the five ordinary stamens, which were unaltered either in form or position. Some partially virescent honeysuckle flowers have a similar structure.

There are other cases of apparent multiplication or duplication, due, probably, rather to the formation of outgrowths from the petals than to actual augmentation of their number. These excrescences occur sometimes on the inner surface of the petals, or of the corolla; at other times on the outer surface, as in some gloxinias, &c. This matter will be more fully treated of under the head of hypertrophy and enation.

Pleiotaxy of the andrœcium.—An increase in the number of whorls in the stamens is very common, especially in cases where the number of circles of stamens is naturally large. The augmentation of the number of stamens is still more frequent where these organs are arranged, not in verticils, but in one continuous spiral line.

InCruciferæthere is always an indication of two whorls of stamens, and this indication is rendered even more apparent in some varieties accidentally met with. So inSaponaria, inDianthus, and otherCaryophylleæ, three and four verticils of stamens have been met with. InLonicera Periclymenuma second whorl of stamens more or less petalodic sometimes occurs.

Moquin mentions a variety ofRubus fruticosusinwhich nearly 900 petaloid organs existed in the place of the twenty-five or thirty stamens natural to the plant, the other organs of the flower being in their ordinary condition, with the exception of the pistil, which did not attain its full size. Baillon records the occasional existence of two rows of stamens inDitaxis lancifolia.

Increased number of stamens in orchids, &c.—Various deviations from the ordinary type of orchid structure have been already alluded to under the head of displacement, fusion, peloria, substitution, &c., but the alterations presented by the andrœcium in this family are so important in reference to what is considered its natural conformation, that it seems desirable, in this place, to enter upon the teratological appearances presented by the andrœcium in this order, in somewhat greater detail than usual. The ordinary structure of the flower with its three sepals, two petals, labellum, column; and inferior ovary, is well known. Such a conformation would be wholly anomalous and inexplicable were it not that the real number and arrangement of parts have been revealed by various workers labouring to the same end in different fields. Thus, Robert Brown, Link, Bauer, Darwin, and others, paid special attention to the minute anatomy and mode of distribution of the vessels; Irmisch, Crueger, Payer, and others, to the evolution of the flower; Lindley, St. Hilaire, and Reichenbach, to the comparison of the completed structures in the various genera and species; while the teratological observers have been numerous, as will be seen from the selected references cited at the end of this paragraph and in other places. The result of this manifold study has been a pretty general agreement that the structure of the order (omitting minor details) is as follows:—A six-parted perianth in two rows, the outer three (sepals) generally regular and equal in shape; of the inner three (petals or tepals) two are regular, and one, the labellum veryirregular, consisting not only of a petal, but of two abortive stamens incorporated with it. The column is considered to be made up of one perfect and three abortive stamens, in inseparable connection with three styles. By some, however, it is supposed that all the stamens are confluent with the column and none with the lip.

Fig.192.—Diagram showing the arrangement of parts in an orchid flower. According to Crüger, the stamens A 2, A 3, should be distinct from the lip. The uppermost figure 2 should have been 1. (See text.)

In either case it is admitted that there are six stamens in two rows. The first row consists of one posterior stamen, which is generally perfect, and two abortive stamens incorporated with the labellum. The second row also consists of three stamens, all of which are usually abortive and inseparable from the column. Traces of them may occasionally be met with in the form of tubercles or wing-like processes from the column. InCypripedium, while the ordinary stamen of the outer row is deficient, two of the inner series are present. The diagram, fig. 192, will serve to show the arrangement of the parts as above described. + represents the situation of the stem or axis; on the opposite side is the bract; between these are placed the sepals, one posterior or next the axis (incorrectly numbered 2 in the plan), two lateral 1, 1; next in order follow the petals, 2, 2, 2, two lateral and somewhat posterior, one larger (the lip), anterior; the outer series of stamens are represented byA1,A2,A3, the two latter being fused with the labellum;a1,a2,a3 represent the position of the inner verticil of stamens, while s, s, s denote the three carpels. It is foreign to the purpose of this book to detail the varied evidence in support of this explanation of the homologies of orchid flowers.[438]All that can be done in these pages is to set forth the evidence furnished by teratology as to this matter—evidence for the most part accumulated and recorded without any special reference to any theory of orchid structure.

The following details all refer to flowers in which the number of stamens in orchidaceous plants was increased beyond what is necessary. They are arranged with reference to the number of adventitious organs, beginning with those in which the number was smallest, and proceeding thence to those in which it was greatest. In some cases it has not been possible to ascertain whether the adventitious organs were really restorations of the numerical symmetry, substitutions of one part for another, stamen for petal, &c., or wholly adventitious productions. Unless otherwise stated, the interpretation put upon the facts thus recorded is that of the present writer, and not necessarily that of the original observer.

Mr. J. T. Moggridge has described and figured a flower ofOphrys insectiferain which there was a vestige of a second stamen present, probably one of the inner series fig. 192 (a2).[439]The same observer also records the presence of a second anther between the lobes of the normal one. This can hardly be referred to either of the typical stamens, but would seem to be a perverted development of the rostellum.[440]Rœper is stated by Cramer[441]to have seen a specimen ofOrchis moriowith two stamens.In a flower ofHabenaria chlorantha, described by the late Professor Henslow,[442]the outer three stamens are suppressed, while two of the inner group are present, as happens normally inCypripedium.A flower ofCattleya violaceaafforded a similar illustration; but in this case only one of the inner stamens was developed, and this in the form of a small petal, partly adherent to the column.InDendrobium normale, Falconer, not only is the perianth regular, but the column is triandrous,[443]the three stamens (according to the diagram of its structure given by Lindley) pertaining to the outer row.In a specimen ofDendrobium hœmoglossumkindly forwarded from Ceylon by Mr. Thwaites there were three stamens present, of which one posterior belonged to the outer seriesA1, and two lateral to the innera1,a2, fig. 192.M. His observed, several years in succession, some flowers of a species ofOphryswith three sepals, no lateral petals, one lip, and three perfect stamens. In this case probably the two supernumerary stamens were petals which had assumed an anther-like character.Wydler describes a flower ofOphrys araniferain which one outer and two inner stamens were present.[444]I have myself met with three such flowers in the same species. The stamens present wereA1,a1,a2.Dr. J. E. Gray exhibited at the Botanical Society of London, in August, 1843, a specimen ofOphrys apiferawith a triandrous column, the supernumerary anthers belonging, apparently, to the inner whorl.In his 'Catalogue of the Plants of South Kent,' p. 56, tab. iv, f. 16, the Rev. G. E. Smith describes and figures a flower ofO. araniferawith a triandrous column, seemingly of the same kind as that spoken of by Dr. Gray.Mr. Moggridge met with a triandrous flower in the same species, and refers the appearance to "a fusion of two flowers, accompanied by suppression and modification."[445]As, however, no details are given in support of this opinion, it may be conjectured that the two additional stamens were members of the inner whorla1,a2, and thus the conformation would be the same as in the flowers just mentioned. The figures given by Mr. Moggridge bear out this latter view, while they lend no support to the hypothesis advanced by him. Nevertheless, no decided opinion can be pronounced by those who have not had the opportunity of examining the flowers in question.Alphonse de Candolle[446]figures a flower ofMaxillariain exactly the same condition, so far as the stamens are concerned, as in the Ophrys flowers just mentioned. It is curious to observe that in many of these cases the two lateral petals are suppressed.Von Martius mentions the occurrence of three anthers (naturaliterconformatæ) inOrchis morio.[447]Richard, as cited by Moquin-Tandon, Lindley, and others, describes and figures a peloria ofOrchis latifoliawith regular triandrous flowers.[448]The writer has examined, in the Royal Gardens at Kew, a flower ofCattleya crispain which were three stamens, the central one normal; the two lateral ones, belonging probably to the inner whorl, were in appearance like the lateral petals, and one of them was adherent to the central perfect column. Duchartre[449]mentions a flower ofCattleya Forbesiiin which there were two labella in addition to the ordinary one, the column being in its normal condition. From the analogy of other cases it would appear as if the additional labella in this instance were the representatives of two stamens of the outer whorl. Beer likewise has put on record the existence of a triandrousCattleya.[450]A specimen ofCatasetum eburneumforwarded by Mr. Wilson Saunders was normal so far as the sepals and two lateral petals were concerned, but the anterior petal or labellum was flat and in form quite like the two lateral ones; the column was normal and in the situation of the two anterior stamens of the outer seriesA2,A3, were two labella of the usual form (fig. 156, p. 291). Perhaps theOncidiumrepresented at p. 68, fig. 29, may also be explained on the supposition that the two lateral lobes of the labellum in this flower were the representatives of stamens.In Fig. 193 is shown the arrangement of parts in a flower ofOphrys aranifera. Here there were three sepals, two lateral petals, one of which was adherent to the side of the column; the central labellum was seemingly deficient, but there were two pseudo-labella placed laterally in the position of the two antero-lateral stamens of the outer series (A2,A3). Within these was another perfect stamen occupying the position of the anterior stamen of the inner series (a3). In another flower of the same species, gathered at the same time (fig. 194), there were three sepals not at all different from those of the normal flower. The three petals next in succession were also, in form and position, in their ordinary state. In colour, however, the two upper lateral petals differed from what is customary, in having the same purplish-brown tint which characterises the lip. Within these petals, at the upper part of the flower, there was the ordinary column, and at the opposite side, alternating with the petals before mentioned, two additional lip-like petals, one provided with a half-anther containing a single perfectly formed pollen-mass (A2,A3). It is, perhaps, worthy of notice that the arrangementof the coloured spots on the true labellum, and that on the adventitious lips, replacing the two lower of the outer stamens, were not of a similar character. The supernumerary lips had theπ-shaped marking which is so common in this species, while the true lip was, as to its spots, much more likeO. apifera. Alternating with this last whorl were three columns, all apparently perfectly formed and differing only from the ordinary one in their smaller size and corresponding toa1,a2,a3. The ovary in this flower was two-celled, with four parietal placentas, thus giving an appearance as though there had been a fusion of two or more flowers associated with suppression and other changes. The position of the supernumerary organs and the absence of anypositive sign of fusion in the bracts or other part of the flower, seemed, however, to negative the idea of fusion.[451]Fig.193.—Diagram showing the arrangement of parts in a malformed flower ofOphrys aranifera(see p. 384).Fig.194.—Malformed flower ofOphrys araniferawith two supernumerary lips and three additional stamens.A similar illustration, for a knowledge of which the writer is indebted to the kindness of Professor Asa Gray and Mr. Darwin, occurred in some specimens ofPogonia ophioglossoidescollected by Dr. J. H. Paine in a bog near Utica, New York. It will be seen from the following description that these flowers presented an almost precisely similar condition to those of theOphrys araniferajust mentioned. "The peculiarities of these flowers," writes Professor Gray, "are that they have three labella, and that the column is resolved into small petaloid organs. The blossom is normal as to the proper perianth, except that the labellum is unusually papillose, bearded almost to the base. The points of interest are, first, that the two accessory labella are just in the position of the two suppressed stamens of the outer series, viz. ofa2 anda3, as represented in the diagram, fig. 192; and there is a small petaloid body on the other side of the flower, answering to the other stamen,a1. Secondly, in one of the blossoms, and less distinctly in another, two lateral stamens of the inner series (a1 anda2) are represented each by a slender naked filament. There are remaining petaloid bodies enough to answer for the third stamen of the inner series and for the stigmas, but their order is not well to be made out in the dried specimens." It may here be mentioned thatIsochilusis normally triandrous.A tetrandrous flower ofCypripediumhas also been recorded.InIsochilus, according to Cruger, there are often five stamens, andthere are several, besides those already mentioned, in which six more or less perfect stamens have been seen—of these the following may be taken as illustrations. A hexandrous flower ofOrchis militarishas been recorded by Kirschleger,[452]and in the accompanying diagram (fig. 195), from Cramer,[453]of a monstrous flower ofOrchis mascula, there is one perfect stamen of the outer row and two lip-like stamens of the same series, while the inner verticil comprises one perfect and two abortive stamens.Fig.195.—Diagram of flower ofOrchis masculawith two additional lips, two perfect and two imperfect stamens (after Cramer).Morren[454]describes some flowers ofOrchis morioin which there were three sepals, three petals, and within the latter two other ternary series of petals; this would seem to be a case of petalody of all six stamens. Morren, however, seems to have considered the additional segments as repetitions of the corolline whorl, though he describes a central mass as the column bearing a "souvenirof the anther." Nevertheless, there is no decisive evidence either in his figure or his description in support of his opinion as to the nature of the central mass, which might be a distorted condition of the styles, or, as is more probable, a rudimentary and irregular flower. Morren also describes another flower of the same plant in which there were three sepals, two lateral petals partially lip-like in aspect, a third labellum normal, two additional labella representing the two anterior stamens of the outer whorl, while more or less developed rudiments of the remaining four stamens also exist.While, in most cases, the supernumerary stamens can, by reason of their relative position, their complete or partial antheriferous nature, be safely referred to one or other of the six stamens, making up a typical orchid flower, there are other specimens in which the additional stamens are altogether adventitious, and do not admit of reference to the homologue. Thus it was in a specimen ofOdontoglossum Alexandræexamined by the writer, and in which, within a normally constructed perianth, there were six columns, all polliniferous, but arranged in so confused and complicated a manner that it was impossible to make out any definite relation in their position. There was nothing to indicate a fusion of flowers, but rather an extension of the centre of the flower, and consequent displacement of the stamens, &c. Again, the existence of adventitious stamens does not necessarily imply the development of organs usually suppressed, inasmuch as they may result from the assumption by the lateral petals of staminal characteristics.Nevertheless, as far as teratology is concerned, specimens may be found in which some or all of the usually suppressed stamens ofOrchidaceæmay be found. These stamens may be all perfect (polliniferous), or, as is more frequently the case, more or less petal-like. Moreover,when the stamens are petalodic, the form assumed is usually that of the labellum.The presence of stamens in undue numbers in orchids is very generally, but not always, attended by some coincident malformation, of which the most frequent is cohesion of two or more sepals, and consequent displacement or adhesion of one petal to the side of the column. Petalody of the styles and median prolification are also sometimes found in association with an augmented number of stamens.

Rœper is stated by Cramer[441]to have seen a specimen ofOrchis moriowith two stamens.

In a flower ofHabenaria chlorantha, described by the late Professor Henslow,[442]the outer three stamens are suppressed, while two of the inner group are present, as happens normally inCypripedium.

A flower ofCattleya violaceaafforded a similar illustration; but in this case only one of the inner stamens was developed, and this in the form of a small petal, partly adherent to the column.

InDendrobium normale, Falconer, not only is the perianth regular, but the column is triandrous,[443]the three stamens (according to the diagram of its structure given by Lindley) pertaining to the outer row.

In a specimen ofDendrobium hœmoglossumkindly forwarded from Ceylon by Mr. Thwaites there were three stamens present, of which one posterior belonged to the outer seriesA1, and two lateral to the innera1,a2, fig. 192.

M. His observed, several years in succession, some flowers of a species ofOphryswith three sepals, no lateral petals, one lip, and three perfect stamens. In this case probably the two supernumerary stamens were petals which had assumed an anther-like character.

Wydler describes a flower ofOphrys araniferain which one outer and two inner stamens were present.[444]I have myself met with three such flowers in the same species. The stamens present wereA1,a1,a2.

Dr. J. E. Gray exhibited at the Botanical Society of London, in August, 1843, a specimen ofOphrys apiferawith a triandrous column, the supernumerary anthers belonging, apparently, to the inner whorl.

In his 'Catalogue of the Plants of South Kent,' p. 56, tab. iv, f. 16, the Rev. G. E. Smith describes and figures a flower ofO. araniferawith a triandrous column, seemingly of the same kind as that spoken of by Dr. Gray.

Mr. Moggridge met with a triandrous flower in the same species, and refers the appearance to "a fusion of two flowers, accompanied by suppression and modification."[445]As, however, no details are given in support of this opinion, it may be conjectured that the two additional stamens were members of the inner whorla1,a2, and thus the conformation would be the same as in the flowers just mentioned. The figures given by Mr. Moggridge bear out this latter view, while they lend no support to the hypothesis advanced by him. Nevertheless, no decided opinion can be pronounced by those who have not had the opportunity of examining the flowers in question.

Alphonse de Candolle[446]figures a flower ofMaxillariain exactly the same condition, so far as the stamens are concerned, as in the Ophrys flowers just mentioned. It is curious to observe that in many of these cases the two lateral petals are suppressed.

Von Martius mentions the occurrence of three anthers (naturaliterconformatæ) inOrchis morio.[447]Richard, as cited by Moquin-Tandon, Lindley, and others, describes and figures a peloria ofOrchis latifoliawith regular triandrous flowers.[448]

The writer has examined, in the Royal Gardens at Kew, a flower ofCattleya crispain which were three stamens, the central one normal; the two lateral ones, belonging probably to the inner whorl, were in appearance like the lateral petals, and one of them was adherent to the central perfect column. Duchartre[449]mentions a flower ofCattleya Forbesiiin which there were two labella in addition to the ordinary one, the column being in its normal condition. From the analogy of other cases it would appear as if the additional labella in this instance were the representatives of two stamens of the outer whorl. Beer likewise has put on record the existence of a triandrousCattleya.[450]

A specimen ofCatasetum eburneumforwarded by Mr. Wilson Saunders was normal so far as the sepals and two lateral petals were concerned, but the anterior petal or labellum was flat and in form quite like the two lateral ones; the column was normal and in the situation of the two anterior stamens of the outer seriesA2,A3, were two labella of the usual form (fig. 156, p. 291). Perhaps theOncidiumrepresented at p. 68, fig. 29, may also be explained on the supposition that the two lateral lobes of the labellum in this flower were the representatives of stamens.

In Fig. 193 is shown the arrangement of parts in a flower ofOphrys aranifera. Here there were three sepals, two lateral petals, one of which was adherent to the side of the column; the central labellum was seemingly deficient, but there were two pseudo-labella placed laterally in the position of the two antero-lateral stamens of the outer series (A2,A3). Within these was another perfect stamen occupying the position of the anterior stamen of the inner series (a3). In another flower of the same species, gathered at the same time (fig. 194), there were three sepals not at all different from those of the normal flower. The three petals next in succession were also, in form and position, in their ordinary state. In colour, however, the two upper lateral petals differed from what is customary, in having the same purplish-brown tint which characterises the lip. Within these petals, at the upper part of the flower, there was the ordinary column, and at the opposite side, alternating with the petals before mentioned, two additional lip-like petals, one provided with a half-anther containing a single perfectly formed pollen-mass (A2,A3). It is, perhaps, worthy of notice that the arrangementof the coloured spots on the true labellum, and that on the adventitious lips, replacing the two lower of the outer stamens, were not of a similar character. The supernumerary lips had theπ-shaped marking which is so common in this species, while the true lip was, as to its spots, much more likeO. apifera. Alternating with this last whorl were three columns, all apparently perfectly formed and differing only from the ordinary one in their smaller size and corresponding toa1,a2,a3. The ovary in this flower was two-celled, with four parietal placentas, thus giving an appearance as though there had been a fusion of two or more flowers associated with suppression and other changes. The position of the supernumerary organs and the absence of anypositive sign of fusion in the bracts or other part of the flower, seemed, however, to negative the idea of fusion.[451]

Fig.193.—Diagram showing the arrangement of parts in a malformed flower ofOphrys aranifera(see p. 384).

Fig.194.—Malformed flower ofOphrys araniferawith two supernumerary lips and three additional stamens.

A similar illustration, for a knowledge of which the writer is indebted to the kindness of Professor Asa Gray and Mr. Darwin, occurred in some specimens ofPogonia ophioglossoidescollected by Dr. J. H. Paine in a bog near Utica, New York. It will be seen from the following description that these flowers presented an almost precisely similar condition to those of theOphrys araniferajust mentioned. "The peculiarities of these flowers," writes Professor Gray, "are that they have three labella, and that the column is resolved into small petaloid organs. The blossom is normal as to the proper perianth, except that the labellum is unusually papillose, bearded almost to the base. The points of interest are, first, that the two accessory labella are just in the position of the two suppressed stamens of the outer series, viz. ofa2 anda3, as represented in the diagram, fig. 192; and there is a small petaloid body on the other side of the flower, answering to the other stamen,a1. Secondly, in one of the blossoms, and less distinctly in another, two lateral stamens of the inner series (a1 anda2) are represented each by a slender naked filament. There are remaining petaloid bodies enough to answer for the third stamen of the inner series and for the stigmas, but their order is not well to be made out in the dried specimens." It may here be mentioned thatIsochilusis normally triandrous.

A tetrandrous flower ofCypripediumhas also been recorded.

InIsochilus, according to Cruger, there are often five stamens, andthere are several, besides those already mentioned, in which six more or less perfect stamens have been seen—of these the following may be taken as illustrations. A hexandrous flower ofOrchis militarishas been recorded by Kirschleger,[452]and in the accompanying diagram (fig. 195), from Cramer,[453]of a monstrous flower ofOrchis mascula, there is one perfect stamen of the outer row and two lip-like stamens of the same series, while the inner verticil comprises one perfect and two abortive stamens.

Fig.195.—Diagram of flower ofOrchis masculawith two additional lips, two perfect and two imperfect stamens (after Cramer).

Morren[454]describes some flowers ofOrchis morioin which there were three sepals, three petals, and within the latter two other ternary series of petals; this would seem to be a case of petalody of all six stamens. Morren, however, seems to have considered the additional segments as repetitions of the corolline whorl, though he describes a central mass as the column bearing a "souvenirof the anther." Nevertheless, there is no decisive evidence either in his figure or his description in support of his opinion as to the nature of the central mass, which might be a distorted condition of the styles, or, as is more probable, a rudimentary and irregular flower. Morren also describes another flower of the same plant in which there were three sepals, two lateral petals partially lip-like in aspect, a third labellum normal, two additional labella representing the two anterior stamens of the outer whorl, while more or less developed rudiments of the remaining four stamens also exist.

While, in most cases, the supernumerary stamens can, by reason of their relative position, their complete or partial antheriferous nature, be safely referred to one or other of the six stamens, making up a typical orchid flower, there are other specimens in which the additional stamens are altogether adventitious, and do not admit of reference to the homologue. Thus it was in a specimen ofOdontoglossum Alexandræexamined by the writer, and in which, within a normally constructed perianth, there were six columns, all polliniferous, but arranged in so confused and complicated a manner that it was impossible to make out any definite relation in their position. There was nothing to indicate a fusion of flowers, but rather an extension of the centre of the flower, and consequent displacement of the stamens, &c. Again, the existence of adventitious stamens does not necessarily imply the development of organs usually suppressed, inasmuch as they may result from the assumption by the lateral petals of staminal characteristics.

Nevertheless, as far as teratology is concerned, specimens may be found in which some or all of the usually suppressed stamens ofOrchidaceæmay be found. These stamens may be all perfect (polliniferous), or, as is more frequently the case, more or less petal-like. Moreover,when the stamens are petalodic, the form assumed is usually that of the labellum.

The presence of stamens in undue numbers in orchids is very generally, but not always, attended by some coincident malformation, of which the most frequent is cohesion of two or more sepals, and consequent displacement or adhesion of one petal to the side of the column. Petalody of the styles and median prolification are also sometimes found in association with an augmented number of stamens.

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