The Journal of Indian Botany/Volume 3/May 1922/Notes on Indian Plant Teratology

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THE

Journal of Indian Botany

Vol. III. MAY, 1922. No. 1.

NOTES ON INDIAN PLANT TERATOLOGY

BY

F. Hallberg,

St . Xavier’s College , Bombay .

I

On a case of simulated abaxial reproductive proliferation of the hypanthium in a flower of Calycopteris floribunda Lamk.

About the middle of March 1921 I came across a few specimens of the shrub Calycopteris floribunda Lamk. close to the dam of the Yehar Lake in Salsette, the plants attracting my attention because of the occasional presence of petals in the flowers, a phenomenon which, as far as I am aware, has not been recorded before. The petals were white, narrowly linear, one to five in number, shorter than the calyx-lobes in flower, and inserted close to the sinus. They were not observed associated with the enlarged fruiting calyx, and turned brown and fell off when a flower was allowed to wither, the calyx- lobes remaining.

While examining these plants, I came across the curious structure shown in Fig. I. in which a complete 4-merous flower bud apparently was subtended by a supernumerary calyx-lobe, iff a flower exhibiting various other irregularities.

At first sight I interpreted this as a case of proliferation of the edge of the hypanthium, the pedicel of the bud in question being fused with the calyx tube. After dissecting the flower, I found however that this explanation could hardly be correct.

The structure is diagrammatically represented in Fig. II. The arrangement of the organs of the main flower is distinctly spiral. Apparently there are seven calyx-lobes (1-711), the innermost subtending the bud mentioned. There are two true petals (a , b), one between the sepals I and II, the other between III and IV. The full number of stamens is present, one of the inner series (8) having an atrophied loculus. The pistil is normal.

If the above interpretation were correct, the mutual arrangement of the series of petals and stamens would be difficult to explain. The following seems much more probable.

At some early stage in the development of the inflorescence, some mechanical agency removed a flower with its bracteole (VII) from the whorl next above that to which the main flower belonged. This may have been effected by the proboscis of some insect. The flower with its bracteole was accidentally grafted on to the calyx-tube below the inner series of stamens of the main flower. At the same time the calyx-tube was ruptured between the stamens 2 and 10 of the inner, and 1 and 9 of the outer series, as indicated by the dotted lines. Einally, the calyx-lobes I and VI are in reality parts of the same initial lobe. This explains the normal position of the petal a and the stamen 1 with regard to the smaller part I, and of the stamens 9 and 10 with regard to the larger part VI. As the wound healed, the dis- placements indicated took place, causing the falsely spiral arrangement.

Diagram of abnormal flower of Oalycopteris floribunda Lamk.

Various other abnormalities of the calyx of other flowers were observed. Thus, the flowers of terminal whorls often had two lobes partially united in various degrees. Also supernumerary calyx-lobes, smaller than the normal ones, were occasionally noted.

II

On some abnormal flowers of Habenaria grandiflota Lindl.

This Orchid abounds on the open grassy spots round Khandala railway station (G.I.P.) on the Western Ghats, in the beginning of the rainy season, before the grass has time to attain any considei f height. Here the specimens described below were collected. 3 plant has a solitary, radical, sub-orbicular leaf and^a short scape, 1 > ing one to four flowers. The petals are normally obliquely bipat **j with a broad upper and a filiform lower segment. The lip is tripai j with a linear-lanceolate middle lobe and filiform lateral segments. , spur is longer than the ovary. i

( 1 ) On a case of perfect pelory in Habenaria gra&difl Lindl.

A single specimen was collected exhibiting this very rare phenomenon (Big. 1).

The flower opens straight upwards, not outwards, as is normally the case in species of this genus, where the ovary is bent or twisted in order to effect the position indicated. The scape is scaleless, and bears only the peloric flower, but opposite the normal bract there is a short undeveloped branchlet.

As may be seen from the figure, the three sepals are undistinguish- able from one another, except for irregularities in the nervation, which shows various transition forms between the 5-and 7-nerved types (the latter being the normal one in the species). The three petals are also alike, 3-nerved, ovate-lanceolate, acute. There are thus no traces of the filiform segments of the normal petals, or of the lobes of the nor- mal lip, and its long spur.

The outer whorl of stamens is fully represented by three complete anthers, each with its two pollinia. The inner whorl is represented by three fleshy, granular staminodes (visible at the base of the petals in the figure). All these structures are morphologically normal.

The stfigma is a triangular structure with a depression in the centre. Each vertex of the triangle forms a rostellum, normal in shape. Along each side, 'on a protuberance, are two pockets, in each of which a gland of a pollinium is resting.

The clavate “Astigmatic ” processes, conspicuous in the normal flower (see either of the columns in Eig. 2), are here totally absent. From their normal position it seems to me probable, that they have to be regarded as the two reduced sfcamens of the outer whorl. But they may of course acquire a stigmatic surface through fusion with parts of the stigma. In our peloric flower the stigmatic surface is presumably situated in the central depression. The ovary is normal, except in showing no trace of bending or twisting.

As far as I am aware, only a single equally perfectly peloric Orchid flower has ever been described. [See : Schlechter & Eiseher — “Pelo- rische Blutenbildiug bei Odo?itoglossum grande Lindl.” Orchis (Beil, 2 . GartenflL), Jahrg. Y (1911), pp. 119—122. Also : Worsdell, W. C. — " The Principles of Plant-Teratology,” vol. II, pp. 82, 94 ; PI. XXXVII, Kgs. 5, 6.]

( 2 ) On two cases of syncmthy in Habenaria grandiflora Lindl.

A. In one of the specimens in question, the scape bears only the dual structure shown in Eig. 2. It is subtended by a bract with two strong midribs, symmetrically placed, and rather far apart. There are two fainter lateral nerves, one on each side. The tip of the double bract is missing. Opposite to the bract, there is a short undeveloped branchlet.

Fig. 2, Two concrescent flowers of Habenaria grandiflora Lindl.

The most noticeable feature of the double structure is the presence of two complete, normal columns, placed side by side, and separated by a two-nerved sepal, apparently a reduced lateral sepal belonging to the flower on the right. Both dor- sal sepals are present, the one to the right being 7-nerved, the other 5-nerved, The two outer lateral sepals are both 3-nerved, and well developed. The two outer petals are nearly normal, 2-nerved. There is no trace of the inner pair of petals. There is only one lip and spur, whether a double structure or not cannot be made out. The opening to the spur is unusually wide. The ovary (Eig, 3) consists of four car- pels, one pair of which is better developed than the other.

Eig. 3. Diagram of ovary common to the flowers of Fig. %.

B. In the other ease under notice, the sy nan thy is less complete, being confined to the ovaries of the flowers concerned (Eig. 4).

Fig, 4. Diagram of two fused ovaries of Habenaria grandiflora Lindl,

In addition to the double structure, the raceme consists of two normal flowers lower down on the scape, The double bract is bicuspidate, with one strong nerve to each tip, and two faint lateral ones on each side. Opposite this bract, there is a small undeveloped branchlet.

As may be seen from the cross-section, which is taken near the widest part of the double ovary, the fusion takes place along the back of two carpels. The contracted tips of the individual ovaries are free, and the flowers are otherwise quite nomal.

( 3 ) On two cases of fusion of the lateral sepals , accompanied by reduction of labellum and suppression of spur in Habenaria grandi- flora Lindl A. In the first ease (Mg. 5) the two lateral sepals have fused to form a boat-shaped structure not unlike the normal dorsal sepal. There are, however two strong midribs, each ending in a small cusp. Another fainter nerve ends in the sinus between the cusps. It probably represents two lateral nerves. In addition, there are two lateral nerves on each side.

The labelium is reduced to a linear acute 1 -nerved structure of about the same length as the sepals. The spur has entirely dis- appeared.

The remainder of the flower is normal.

B. In the second ease of fusion of the Iaterel sepals, the resulting double structure cannot be distinguished from the dorsal sepal, except by its being 7-nerved, the latter being 5- nerved. Here the lip is reduced to a small fleshy process, rather like a “stigmatic” lobe in a normal flower, although about twice as long. As in the last case, there is no trace of a spur. The stigmatic lobes are also totally absent. Instead the basal lobes of the rostellum are considerably larger than usual’ whether due to mere over-development or to fusion with stigmatic parts not being apparent.

(For another abnormality in the same specimen, see next section.)

(4) On a case of laminar outgrowths from the midrib of a double bract m Habenaria grandiflora Lindl. The abnormal flower described in section (3) B. has its pedicel fused with that of another, normal flower, the two flowers being the only ones on the scape, and subtended by an interesting double bract (Eig, 6). The constituents are fused along the midribs of their dorsal

Fig. 6. Laminar outgrowths in a double bract of Habenaria grandiflora Taindl

surfaces. The two leaf-halves, nearest the flowers, are reduced, and devoid of nerves. Their dorsal surfaces are fused in their lower third parts to the pedicel of the normal flower. The other two leaf-halves are well developed, each with two lateral nerves, and the fusion is so perfect, that if the reduced pair were absent, the structure would be morphologically undistinguishable from a normal bract. Opposite the double bract, there is a small undeveloped branchlet, representing the displaced main part of the scape.