Page:The Botany of the Antarctic Voyage.djvu/280

248 the perianth, we may presume that they belong to that series of those organs, which are opposite the petals in decandrous Alsinece and generally suppressed in the pentandrous, and that the other series is represented by two thickened glands, placed between the bases of the stamens, rather externally to them, and opposite the two inner segments of the perianth ; they are very conspicuous in S. muscoides, (part i. p. 14) and more or less evident in most species. One of my specimens was provided with 5 stamens, the fifth being opposite one of the larger sepals. During my examination of the Campbell Island variety, I was led into an error. In it the seeds germinate before leaving the capsule, and sending their radicles through the receptacle into the peduncle, and their cotyledonary leaves upwards between the valves of the seed-vessel, I described the axis of the capside or the receptacle of the seeds as proliferous.

This genus, which I formerly arranged (following Fenzl.) with thePorttdacea, I have now included in Alsinece proper, from its near affinity with Sacjina and Spergula; the limits between these two orders are so confessedly undefineable, that I need scarcely do more than indicate the most remarkable points of similarity between this genus and the majority of the Portulacece ; which are, the distinctly perigynous stamina and their being alternate with the segments of the perianth. The perigynous insertion of the stamina can hardly be considered foreign to the Alsinece, for it is seen in Larbrcea, a genus in all other respects nearly allied to Stellaria, also iu Clterleria and some species of Arenaria itself, plants wlrich by some have been removed to Portulacece, on no other ground than because the staminiferous disc, (so conspicuous in another form, as the anthophorus of Silenea), and which probably exists throughout the order, is more ddated in these plants. The close affinity of Colobanthus with Sagina may be perceived in the prevailing tetramerous arrangement, and in two of the segments of the perianth being always external and larger than the others, in the suppression of the petals, and in the perigynous insertion of the stamina, which equal the sepals in number ; the chief difference between them lies in the stamens of the former being alternate with the calycine pieces, and those of the latter opposite to them. Colobanthus shews a further peculiarity in the valves of the capside being opposite to the stamens and alternate with the sepals, whilst in Sagina and most other tetrandrous or pentandrous Ahinece, they are opposite both to the stamens and sepals. Here then the anomaly rests, either in the position of the valves of the capside of Colobanthus, the stamens being still considered as belonging to the series opposite the petals, or in the situation of the segments of the perianth, which if opposite the stamens, woidd present an arrangement of parts exactly like Sagina, where stamens, sepals and valves are all opposite one to another.

Plate XCIII. Fig. 1, portion of stem and pair of leaves ; fig. 2, flower ; fig. 3, the same laid open ; fig. 4, a flower of the Campbell Island variety ; fig. 5, ovarium of Falkland Island variety, cut open; fig. 6, capsule, and fig. 7, seed from the same ; fig. 8, the same cut open, shewing the embryo : — all magnified.

Colobaxtrtjs crass'ifolius, Hook. fil. ; glaberrimus, esespitosus, crassiusculus, caulibus plurimis erectis ramosis, foliis linearibus obtusis rnucronatisve basi vaginantibus, pedunculis folio brevioribus post anthesin elongatis, floribus 4-5-meris, perianthii segmentis ovatis v. ovato-lanceolatis obtusis capsulani apice 5-valvem subsequantibus v. longioribus. Sagina crassifolia, If Urville in Mem. Soc. Linn. Paris, vol. iv. p. 617. Gaud. in Frei/c. Toy. p. 137. Colobanthus Quitensis, et C. saginoides, Bartling, et Presl, Beliq. Hank. vol. ii. p. 1 3. t, 49. f. 2.

Hab. Strait of Magalliaens, Port Famine ; Capt. King. Hermite Island, Cape Horn ; /. D. H. Falkland Islands; If Urville, J. D. H.

The figure of this plant in the " Reliquiae Hamkianae" is sufficient for the determination of the species, though I do not coincide with Bartling in considering it the Sagina Quitensis of Humboldt and Kunth, which is described as having filiform stems and four small bracteae on the peduncles. I have little doubt that the latter plant is a Colobanthus, for the stamens are described to be alternate with the segments of the calyx, but probably a very different species. Specimens of C. crassifolim gathered on the Andes of Chili, have the capsule so much longer than the perianth, as