Vegetable Teratology Part 72

NOTE.

During the progress of the foregoing pages through the press, several additional ill.u.s.trations of particular malformations have come under notice. Some of the more important of these may here be recorded.

_Fasciation_ (see p. 11).--The following plants may be added to the list:--_Acer eriocarpum_, _Arabis albida_, _Bra.s.sica oleracea_, var., _Guarea_, sp., _Artabotrys_ sp. In all, with the exception of the first-named, the fasciation occurred in the inflorescence. In some species of _Artabotrys_, indeed, fasciation and curvation of the inflorescence are common.

_Synanthy_ (p. 39).--Several additional instances of adhesion of two or more flowers in _Calanthe vest.i.ta_, _C. Veitchii_, and other forms of this genus may be cited. These furnish further ill.u.s.trations of the much greater liability of some plants to particular changes as compared with others. _Scilla bifolia_, _Gagea arvensis_, and _Viola odorata_ may be added to the list of synanthic plants.

_Alterations of placentation, &c._ (see pp. 98, 483).--M. Casimir De Candolle, in a letter to the author, dated March 8th, 1869, thus writes of the existence of a double row of carpels in _Pyrus spectabilis_ and _Crataegus Oxyacantha_, "a longitudinal section of a double flower of _Pyrus spectabilis_ shows two rows of carpels, placed one above another.

The arrangement of the vascular bundles shows that the upper row is external in relation to the lower series. The carpels of the latter are wholly coalescent as in a pear, while those of the upper verticil are only partially coherent or sometimes quite distinct. The placentation is constantly axile in the inferior row and parietal in the upper one. The number of ovules in each carpel of the superior row varies greatly, and they are often, but not always, inserted in two longitudinal ranks, as is constantly the case in the lower carpels. Double flowers of _Crataegus Oxyacantha_ present the same anomalies." For a.n.a.logous instances in _Digitalis_, see p. 98. See also p. 380, _Saxifraga_.

_Prolification_, p. 120.--A. P. De Candolle, "Organographie Vegetale,"

tab. 40, figures an instance of suppression of one lobe of the ovary in _Iris chinensis_, and of the presence at the base of the flower of an advent.i.tious and imperfect flower-bud, as in the _Phlomis_, mentioned at p. 119.

_Monoecious Misleto_, p. 193.--In this specimen, exhibited at one of the meetings of the Scientific Committee of the Royal Horticultural Society in 1869, there were both male and female flowers on the same bush. The plant was of the male s.e.x, with numerous long slender whip-like, somewhat pendulous, branches bearing comparatively large broad yellowish leaves, and fully developed male flowers at the end. From the side of one of these male branches, near the base, protruded a tuft of short, stiff branches, bearing small, narrow, dark green leaves, ripe berries and immature female flowers. There was no evidence of grafting or parasitism, of the female branch on the male, the bark and the wood being perfectly continuous so that the only tenable supposition is that this was a case of dimorphism.

_Advent.i.tious leaflet and pitcher_, see pp. 30 and 355. In a species of _Picrasma_, in which the leaves are impari-pinnate and spread horizontally, an advent.i.tious leaflet was observed to project at right angles to the plane of the primary leaf. It emerged at a point nearly corresponding to that at which the normal pinnae were given off. The appearance presented was thus like that of a whorl of three leaves, except that the shining surface of the advent.i.tious leaflet, corresponding to the upper face of the normal leaflets, was directed towards the axis, _i.e._, away from the corresponding portion of the neighbouring pinnae, while the dull surface, corresponding to the lower part of an ordinary leaflet, looked towards the apex of the main leaf, or away from the axis. In one instance, a stalked pitcher was given off from the same point as that from which the supernumerary leaflet emerged, the pitcher being apparently formed from the cohesion (congenital) of the margins of a leaflet.

In the normal leaf of this plant there is between the bases of the pinnae, a small reddish gland or stipel? attached to, or projecting from, the upper surface of the rachis. It appeared from some transitional forms that the advent.i.tious leaflet, just mentioned, was due to the exaggerated development of this gland, but no clue was afforded as to the origin of the ascidium. It was not practicable to examine the arrangement of the vascular bundles in the rachis.

_Additional labella in Phaius._--A flower of _Phaius grandiflorus_ was found in the same condition as the _Catasetum_, mentioned at pp. 291 and 382.

_Tubular stem._--A species of _Sempervivum_, exhibited by Mr. Salter, of Hammersmith, at one of the summer exhibitions of flowers at the Royal Horticultural Society in 1868, under the name of _S. Bollei_, deserves notice from its bearing on the question of such structures as the calyx-tubes, the hip of the rose and such like, see pp. 394, 482. In this plant the leaves appeared to be arranged some on the outside, others on the inside, of an erect hollow cylinder, some six inches in height. The oldest leaves were outside, the youngest within, so that the appearance presented was as if the summit of the axis had been pushed or drawn in, much as the finger of a tight glove might be inv.a.g.i.n.ated in withdrawing it from the hand.

The plant in question thus furnishes an actual ill.u.s.tration of the supposit.i.tious case mentioned at p. 482.

_Double flowers_, see pp. 499, et seq.--The following species may be added to those already recorded: _Lychnis coronaria_, _Hibiscus mutabilis_, _Lotus major_, _Pisum sativum_, _G.o.detia_ sp., _Ipomoea purpurea_, _Convolvulus minor_, _Heliotropium peruvianum_, _Trillium grandiflorum_, and _Phaius grandiflorus_.