Page:The Botany of the Antarctic Voyage.djvu/130

108 and in the little island of Trinidad, in lat. 20° S., where we effected a landing with considerable difficult}', in a rocky cove which was cut off by precipices from all other parts of the island, I found the Ferns at the level of the sea in the proportion of 2-3 to the phsenogamic plants, and the species were the most common Brazilian ones. This remarkable disparity between the vegetable productions of two islands so contiguous as St. Helena and Ascension, and both so remote fi-om any other land whatever, has some analogy to what obtains in the islands of another isolated group, also situated within the Tropics, though in another ocean — the Galapagos. From the examination of an excellent herbarium formed by Mr. Darwin in three of these islands, and of some of the plants from a fourth island, as well as of those collected by Mr. Douglas, Dr. Scouler, Mr. Macrae, and Mr. Cuming, in the localities also visited by Mr. Darwin, it would appear not only that the plants of that little archipelago differ widely from those of the main land of S. America, but that its several islets possess in some cases different genera, and more often representative species. The Ferns there bear but a small proportion to the whole Flora, though a more considerable one to that of the two islands in which they are most abundant, and they are rather the common forms of the West Indies than of the neighbouring coasts of Columbia, Peru, or of Mexico.

The Aspidium venustum, as it grows in the low woods of Lord Auckland's group, is, for its size, among the most ornamental of Ferns, the larger tree-ferns alone excepted. In one respect it even excels those of more majestic growth, for its feathery fronds are spread out below the level of the eye, so that the beautiful symmetry of the crown, with its rich velvetty crosier-formed young leaves in the centre, is thus fully displayed.

3. ASPLEMUM, L.

1. Asplenium obtusatum, Forst. Prodr. n. 430. Lab. Fl. Nov. Holl. v. 2. p. 93. t. 242. f. 2. Brown, Prodr. p. 150. Sehhuhr, Ml. v. 1. p. 6. t. 68. Hombr. et Jacq. in Toy. aw Pole Sud, Bot. Monocot. Crypt. 1. 1. A. (sine descripf.).

Tar. IS. obliquum; — A. obliquum, Forst. Prodr. v. 429. Labillard. I.e. t. 242. f. 1. Sclikulir, 1. c. t. 71. A. cliondropliyUiun, Bertero in Herb. Hook. A. apicidentatum, Hombr. et Jacq. 1. c. t. 1. A. (sine descripf.).

Hab. Lord Auckland's group and Campbell's Island ; very common on the rocks near the sea and at the margins of the woods.

All the various stages between the A. obliquum, Forst., and A. obtusatum, Forst., exist in Lord Auckland's group, and probably in other islands of which this plant is an inhabitant ; one of the specimens indeed, is intermediate between the excellent delineations of the two given by Schkuhr. MM. Hombron and Jacquinot have also figured both the states (from Lord Auckland's group), retaining them under the name of "obtusatum," and added to the plate a representation of another, under the name of A. apicidentatum, which is equally abundant with the others, and I have been unable to distinguish it even as a variety ; the production of the apex of the pinna into a tooth, not affording a constant character. I have not quoted the Flora of Mr. Cunningham, or of M. A. Richard, the former not having gathered this species at the time of the publication of his Prodromus, and the latter author, considering it identical with A. htcidum, Forst., leaves it doubtful whether he knew both species. Besides the greater size, different texture, and shining surface of the A. htcidum, its involucres are always very much narrower and longer in proportion to the breadth of the frond. Both are common to many parts of the southern hemisphere, and are particularly frequent in the Pacific Islands.

I have retained the name of obtusatum for this species, that variety being the more frequent of the two described by Forster.