Vegetable Teratology Part 54

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 advent.i.tious, and do not admit of reference to the h.o.m.ologue.

Thus it was in a specimen of _Odontoglossum Alexandrae_ examined 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 advent.i.tious stamens does not necessarily imply the development of organs usually suppressed, inasmuch as they may result from the a.s.sumption 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 of _Orchidaceae_ may 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 a.s.sumed 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 a.s.sociation with an augmented number of stamens.

[Ill.u.s.tration: FIG. 196.--Increased number of carpels, tulip.]

[Ill.u.s.tration: FIG. 197.--Fruit of St. Valery apple cut lengthwise.]

=Pleiotaxy of the gynoecium.=--An increase in the number of whorls of which the pistil consists is not of very frequent occurrence. Generally after the formation of the whorl of carpels, the energy of the growing point ceases, or if by chance it be continued, the result is more generally the production of a new flower-bud (median prolification) than the repet.i.tion of the carpellary series. It is necessary also to distinguish between the veritable augmentation of the pistil and the semblance of it, brought about by the subst.i.tution of carpels for some other organs, as pistillody of the stamens, and even of the segments of the perianth, is not very unfrequent, as has already been stated under the head of subst.i.tution. Again, the increased number of carpels which is sometimes met with in such flowers, as _Magnolia_ or _Delphinium_, where the ovaries are arranged in spiral series, is not strictly referable to the present category.

The orange is one of the plants most frequently subject to an augmentation in the number of carpellary whorls; sometimes this is due to the stamens a.s.suming the guise of carpels, but at other times the increase occurs without any alteration in the stamens or other organs.

If the advent.i.tious carpels be exposed, they are covered with yellow rind, while those portions that are covered by the primary carpels are dest.i.tute of rind. Some varieties of the double tulip are very subject to a similar change, but, in this case, the petals and the stamens very frequently become more or less carpellary in their nature. Fig. 196 represents an increased number of whorls of carpels in the variety called "rex rubrorum," the segments of the perianth having been removed.

In the St. Valery apple, already referred to, there is a second whorl of carpels above the first, a fact which has been made use of to explain the similar structure of the pomegranate.

The tomato (_Lycopersic.u.m esculentum_) is another plant in which an advent.i.tious series is frequently produced, and generally in combination with the primary series.

In the Chinese primrose (_Primula sinensis_) a supernumerary whorl is frequently met with, generally a.s.sociated with other changes in the construction and arrangement of the parts of the flower.

M. de Candolle[455] mentions a flower of _Gentiana purpurea_ with four carpels in one series, and five others in the circle immediately above them. Wigand[456] alludes to an instance wherein there was a second pair of carpels above the first in _Vinca herbacea_. Dr. Sankey has forwarded flowers of a _Pelargonium_ having a double series of carpels, eight in the outer row, five in the inner, and this condition is stated to exist in the flowers of the same plant for two years consecutively. In _Aquilegia_ I have met with a similar increase in the whorls of carpels.[457] Meissner records a similar augmentation in _Polygonum orientale_.[458]

Wigand[459] describes and figures a flower of _Vinca minor_, in which there were two carpels intervening between the ordinary pair, and a similar ill.u.s.tration has been observed by the writer in _Allamanda cathartica_. Eichler[460] has put on record a similar case in a capparid.

Marchand[461] mentions a polycarpellary berberid (_Epimedium Musschianum_). The supernumerary carpels in this flower were placed on a short axis, which originated in the axils of the stamens, and as these latter organs were present in their usual number and position, the advent.i.tious carpels could not be considered as resulting from a transformation, or subst.i.tution of carpels for stamens.

Lastly, the instance cited by Dr. Allman[462] in _Saxifraga Geum_ may be alluded to. Here there was a row of advent.i.tious carpels between the stamens and pistils, the backs of the carpels being turned towards the axis of the flowers. Dr. Allman explains the presence of the supernumerary parts by the supposed production of a whorl of secondary axes between the stamens and the centre of the flower. These axes are further supposed to bear imperfect flowers, of which the additional carpels are the only traces, but this explanation seems forced.

In addition to the references already cited the following may be given:

Duchartre, 'Ann. Sc. Nat.,' 4 ser., vii, p. 23 (Tulip).

Ferrari, 'Hesperides,' pp. 271, 395, 405. Duchartre, 'Ann. Sc.

Nat.,' 4 ser., 1844, vol. i, p. 294. Maout, 'Lecons Element.,'

vol. ii, pp. 488-9. Clos, 'Ann. Sc. Nat.,' 1865, p. 317 (_Citrus Aurantium_).

Clos, 'Bull. Soc. Bot. Fr.,' vol. xiii; 'Rev. Bibl.,' p. 75.

Pasquale, 'Reddicont Accad. Sc. Fis. e Math. Napoli.' Octr.

1866 (_Solanum Lycopersic.u.m_).

On the general subject of multiplication, in addition to previous citations, the reader may be referred to A. P. de Candolle, 'Theorie Element. Bot.,' ed. 3, p. 89.

=Increased number of flowers in an inflorescence.=--This happens generally as a result of over luxuriant growth, and scarcely demands notice here, being rather referable to variation than to malformation.

The increased number of florets in the spikelets of some gra.s.ses has already been alluded to (p. 351). Thus spikelets of wheat occasionally produce more than the three florets which are proper to them.[463] It will be remembered that in this as in many other gra.s.ses there are rudimentary florets, and it is no matter for surprise that these florets should occasionally be fully developed.

FOOTNOTES:

[392] 'Bull. Soc. Bot. Fr.,' vol. vii, 1860, p. 587.

[393] 'Fragment. Phyt. Austral.,' part xx, p. 270.

[394] 'Bull. Acad. Belg.,' xvi, pt. i, p. 60, "Fuchsia," p. 125, c. ic.

[395] "Theorie de la feuille," 'Arch. des Sciences Bibl. Univers.,'

1868.

[396] See Engelmann, 'De Antholysi,' p. 16, section 12.

[397] Verhandl. des Botanisch. Vereins Brandenburg,' 1859, 1 heft.

[398] See Henslow. 'Mag. Nat, Hist.' 1832, vol. v, p. 429.

[399] 'Phytologist,' September, 1857.

[400] Seemann's 'Journal of Botany,' iv, p. 168, t. 47, f. 3.

[401] 'Ill.u.s.t. Hortic.,' 1866, misc., p. 97.

[402] See Fresenius, 'Mus. Senkenb.,' bd. 2, p. 43. Schlechtendal, 'Bot.

Zeit.,' iv, pp. 403, 492, _Veronica tetrandra_.

[403] 'Flora,' 1865, tab. 6, fig. 8.

[404] 'Org. Veget.,' t. i, p. 497, pl. 42, f. 3.

[405] 'El. Ter. Veg.,' p. 354.

[406] Cited in "Rev. Bibl." of 'Bull. Soc. Bot. Fr.,' 1866, p. 171.

[407] Loc. cit., 351.

[408] 'Mem. Acad. Toulous.,' vi, 1862, ex 'Bull. Soc. Bot. Fr.,' "Rev.

Bibl.," vol. ix, 1862. p. 127.

[409] 'Flora.' 1857. p. 289.

[410] L. c., p. 354.

[411] Giraud, 'Ed. Phil. Mag.,' Dec., 1839.

[412] See _Cerasus Cap.r.o.niana_, D. C. 'Plant. Rar. Hort. Genev.,' tab.

18.

[413] Nees, 'Linnaea,' v, p. 679, tab. 11 (_Schoenodorus_).

[414] 'Gard. Chron.,' 1852, p. 452.