This change, or rather this persistence of a form that is usually transient, is generally accompanied by some other alterations. Change of direction, as has been already mentioned, is one of the most common of these; separation of the petals (Antirrhinum, Verbascum, &c.), and even their appearance in leaf-like guise, are not infrequent (Delphinium, Antirrhinum, Verbascum, &c.) At other times multiplication or increased number of the whorls of petals takes place, often, but not always, at the expense of the sexual organs of the flower. Perhaps even more frequent is the increased number of parts in the same whorl in cases of regular peloria; thus, in the Pelargoniums before alluded to, the parts of the flower are frequently regulated by the number six instead of five.
This form of peloria is most generally met with in flowers that are placed at the end or in the centre of the inflorescence, or in such flowers as occur singly at the end of the flower-stalk, as in Tropæolum, Viola, &c. It would hence seem as if the freedom from pressure or restriction on one side allowed the flower to develop equally in all directions, and thus to produce regularity of form.
It is obvious, from what has been before said, that the process of fertilisation is in many cases interfered with and altered by the change in the conformation or the flower.
From overlooking the occasional existence of this form of peloria, new genera have sometimes been formed on insufficient grounds. The genus Aceranthus, for instance, consists of species of Epimedium in which the customary spurs are not formed.[229]
The occurrence both of regular and irregular peloria on the same plant has frequently been observed in Linaria. It has also been remarked that the seedlings raised from these forms are not always constant; thus, the late Mr. Crocker, formerly foreman in the Royal Gardens, Kew, informed me that he fertilised some flowers of a drooping Gloxinia with their own pollen, and that when the seedlings blossomed a large number of them produced the erect regular flowers.
From what has been already said it will be seen that regular peloria is closely allied to what Morren called epanody, or a return to the normal condition. The reversion of a monstrous form to the normal one, as, for instance, when the fern-leaved beech reverts to the normal type, was called by the same author epistrophy.[230]
The following are the genera in which regular peloria has been most often observed. It must, however, be remarked that in some of the flowers recorded as peloric there is no indication as to which form of peloria the case should be referred to. For other illustrations refer to chapters on Heterogamy, Number, Irregular Peloria, &c.
- *Delphinium peregrinum!
- *Nigella damascena!
- *Aquilegia vulgaris!
- *Viola odorata!
- hirta.
- Epimedium, sp.
- *Pelargonium zonale!
- *inquinans!
- Tropæolum majus!
- *Wistaria sinensis.
- Lupinus.
- *Cytisus Laburnum!
- Trifolium repens!
- *Compositæ, gen. pl.!
- Lonicera Periclymenum!
- Streptocarpus Rexii.
- *Digitalis purpurea.
- *Scrophularia aquatica.
- *Pentstemon.
- *Linaria vulgaris!
- *Antirrhinum majus!
- Verbascum nigrum!
- Columnea Schiedeana.
- Halenia heterantha.
- Galeobdolon luteum.
- Prunella vulgaris!
- Salvia, sp.!
- Teucrium campanulatum.
- Betonica alopecuros.
- Eccremocarpus scaber.
- Pedicularis sylvatica.
- Zingiber Zerumbet.
- Phalænopsis amabilis!
- Phalænopsis Schilleriana.
- Habenaria.
- *Orchis morio.
- mascula.
- *Dendrobium, sp.
- Atriplex, sp.
- Cattleya Mossiæ!
- marginata.
- Calanthe vestita!
- Oncidium, sp.!
- Selenipedium caudatum.
- Arum maculatum.
In addition to the references already given, further information on this subject may be gained from consulting the following publications. See also Irregular Peloria.
Giraud, 'Bot. Soc. Edinb.,' Dec. 12, 1839, Antirrhinum. Dareste, 'Ann. Sc. Nat.,' ser. 2, 1842, xviii, p. 220, Delphinium. C. Morren, 'Fuchsia,' p. 90, Calceolaria, 'Bull. Acad. Belg.,' xx, part ii, p. 57; and E. Morren, 'Bull. Acad. Belg.,' 2nd ser., xix. p. 224, Gloxinia. Richard, 'Mém. Soc. d'hist. nat.,' ii, p. 212, tab. 3. Lindley, 'Journ. Linn. Soc.,' iii, p. 9, Dendrobium. Michalet, 'Bull. Soc, Bot. France,' vii, p. 625, Betonica. Gubler, 'Bull. Soc. Bot. Fr.,' ix, 81, 'Des anomalies aberrantes et regularisantes.' Reichenbach fil. 'De pollinis orchid. genesi ac structura,' 1852, Oncidium. Clos, 'Mém. Acad. Toulouse,' vi, 1862, Salvia. Caspary, 'Verhandl. Phys. Œkon. Gesell. Königsberg,' 1860, i, 59, Columnea. Bureau, 'Bull. Soc. Bot. Fr.,' 1861, vol. viii, p. 710, Streptocarpus. Darwin, 'Variation of Animals and Plants,' ii, pp. 59 and 396. Godron, 'Ex. Bull. Bot. Soc. Fr.,' xiv, p. 165, 'Rev. Bibl.,' Wistaria. Marchand, 'Adansonia,' iv, p. 172, Lonicera. Baillon, 'Adansonia,' v, p. 177, 'Sur la regularité transitoire de quelques fleurs irreg.,' shows that during the development of some flowers which begin and end by being irregular, there is an intermediate state when all the parts are regular. Helye, 'Revue Horticole,' Sept., 1868, p. 327. In this last paper, published as this sheet is going through the press, the author states that he has raised from seed three generations of plants of Antirrhinum with regular spur-less flowers. The original wild plant was only partially peloric, but all the flowers produced on its descendants were regular.