Page:The Botany of the Antarctic Voyage.djvu/83

Campbell's Islands.] coriacea, olivaceo-fusca, basi profunde emarginata circumdata. Testa membranacea. Embryo clavaformis, orthotropus.

This is not only a beautiful, but a very remarkable plant, and one of the greatest ornaments to the barren hills it inhabits, the flowers being nearly as large as those of V. elliptica, Forst., and of a most beautiful blue colour. In the pedicellate flowers, crowded upon an erect, leafy, terminal raceme, a few of which only expand at one time, it is more nearly allied to some of the British herbaceous species than to the shrubby group of New Zealand. It may also be remarked, that two of the largest-flowered species, whose corollas are of the finest blue, are more alpine in their habitats than most of their congeners, as is the case with this plant and with the V. saxatilis of the European Alps.

In garden specimens of the V. speciosa, R. Cunn. (Bot. Mag. t. 4057), I have observed the calyx and corolla to vary in the number of parts, from three to four, but I am not aware that the stamens in any species except the present ever exceed two, or that the corolla is constantly pentamerous. The V. decussata, Ait. (elliptica, Forst.) is figured and described in the 'Botanical Magazine' by Mr. Curtis (t. 242) as sometimes having five parts to the corolla, which is the nearest approach I know of to the present case. I shall however first point out the remarkable structure of the calyx, before more fully describing the corolla.

The calyx is constantly 5-cleft; the segments very large and singularly unequal in size, two being much larger than the rest, always external and of the form of cauline leaves; the other three are nearly equal, so that at first sight the calyx appears 3-cleft, with two lateral bracts on its base; the large segments are however remote from the true bract on the base of the pedicel. Neither of these is the posticous lobe, nor is the solitary smaller one placed between them, which is the lowest; but the two others, one of which is a little larger than the other, are nearly opposite the back lobe of the corolla.

The corolla is rather variable in form; when regularly developed it is 5-cleft, with rather broad, nearly equal, patent segments, the two lowest being the smallest, the upper the posticous. The segments are however often so very equal in size, that, from their appearance alone, it is not possible to judge which is the upper one. The increased number of parts might be supposed to arise from the division of the back lobe, which is in so many Veronicas the larger, and the stamens would thus be placed one at the outer base of two contiguous segments. This however is not the case in any 5-cleft flowers; when diandrous, only one segment separates them, which I have seen to be the upper when they are equal in size, and it is more evidently so when two of the lobes are smaller than the rest, which are then placed opposite the two stamens and are the lower. The additional lobe is formed thus from the division of the lower, or what is generally the smaller, lobe in others of the genus. Some analogy to this structure may be found in the case of V. nivea, nob. (Icon. Plant, t. 640), which has the lower lobe truly bifid, as I have proved by an examination of other specimens, and not accidentally, as suggested in the description of that plant on its first publication. In some spikes all the flowers are ringent, the tubes of the corollas longer, and the segments narrower than in the normal state of the plant. Of these some are 6-cleft, of which I found two instances, one diandrous and the other triandrous. In the diandrous flower the sixth lobe was formed from the division of the upper or posticous lobe into two unequal segments, and one of the stamens was abortive and inserted lower in the tube of the corolla than the other. In the triandrous specimen the sixth lobe was due to the splitting of the lower into three. We have here instances of both the upper and lower segment in this species becoming divided. I never saw any tendency in either of the lateral ones to divide, further, than that, in one instance of a 5-lobed corolla, one of these had a large tooth on its lower margin. Three-lobed corollas are rare; the two I examined were regular, with the segments nearly equal and very broad. The genus Veronica is generally described as having the upper or back lobe the largest; this is not constantly, though often the case, but the lower lobe is generally the smallest, sometimes remarkably so. In V. nivea, mentioned above, the lateral divisions are much the largest, as is the case with V. Cataract&aelig;, Forst., and its ally V. diffusa, nob., very distinctly. The V. tetragona, Hook. (Icon. Plant, t. 580) is figured with the upper lobe bifid; it is probably rarely so, as in all the specimens I examined it was quite entire.