Page:The Botany of the Antarctic Voyage.djvu/50

28. Lord Auckland's group; on banks near the sea.

In many respects this species is intermediate between the two former, but is equally distinct from both, and so nearly allied to the L. scariosa, as to induce me to adopt the name of propinqua; it differs from that plant in its much larger size, more divided leaves and very woolly habit. The genus Leptinella appears to have been hitherto but little understood by botanists; it was founded by Cassini in 1822, upon (apparently very imperfect) specimens of two plants whose habitat was entirely unknown. In 1841 it was again taken up by the authors of 'Contributions to a Flora of South America, &c.' (vide Hook. Journ. Bot. vol. iii. p. 325), where a supposed new species, L. ac&aelig;noides, H. and Arn., is described. This latter is a very common plant in the extreme south of the American continent, and we have assumed it to be the L. scariosa of Cassini and DeCandolle, the leaves and peduncle being either smooth or hairy in that plant. There are still some characters described by the above-mentioned authors as belonging to that genus which my specimens do not exhibit. Thus all the flowers are stated in one species to be females: I do not find this to be the case; nor should much stress be laid upon a peculiarity of structure, drawn from a single capitulum "dont les fleurs sont extr&egrave;mement petites et d&eacute;figur&eacute;es ou alt&eacute;r&eacute;es par la d&eacute;siccation et la compression" (Cassini in Dict. Sc. Nat. vol. xxvi. p. 67). In all the plants of the genus which I have examined, the heads of flowers are mon&oelig;cious; but the flowers of the disc especially, being all males, are, after the performance of their functions, easily displaced by pressure. The "long, straight, linear, obtuse, bracteiform leaf" (Dict. Sc. Nat. l.c.) at the base of the peduncle is also not apparent; nor am I able to conceive to what organ of our plant this can apply, except a young cauline leaf, generally present near the peduncle, can have assumed such a form or suffered mutilation. On the other hand, the description of the involucral scales, covered, as are the flowers, with glands, and the characters drawn from those organs themselves, will, collectively, accord with no other plants that have ever fallen under my notice. The second described species, L. pinnata, seems hardly to differ from the L. scariosa, except indeed that the notice of the above-mentioned glands is under it omitted; but Cassini further mentions the singular character of the female corolla being "enfl&eacute;e," an anomalous structure, upon which I shall here offer a few remarks.  In all the four species of the genus with which I am acquainted, the style of the flowers of the ray is invested, or sheathed loosely, by a very delicate hyaline tube, marked, in several instances, by distinct slender nerves, always five in number. This tube enlarges around the swollen bulb of the style and is inserted underneath it into the apex of the ach&aelig;nium: at its summit it meets the inflated corolla, and in the form of a membrane or tissue completely continuous with it, they together constitute the four obtuse, inconspicuous, rounded lobes of the corolla. The latter organ, thus viewed, consists of two distinct membranes, united above and perhaps below. On first observing this structure in L. plumosa, whose flowers are not furnished with glands, and whose corolla is, so far as I can detect, entirely nerveless, I was inclined to consider the corolla as reflected upon itself, the reflected portion entirely investing and concealing the real tube: because I was unable to trace any intervening tissue connecting the two parietes or opposite coats, where an apparent complete vacuity exists; and especially because in some allied genera of Cotule&aelig;, and in other plants not far removed from the present genus, the corolla is reflected, and in a Tasmanian species as much as half-way down its whole length, its lower free margin being obscurely four-lobed; and in Otochlamys, DeC., its base is produced downwards so as to hide a great portion of the ach&aelig;nium. On the other hand, in the three species which are supplied with glands, it is only the outer surface of the exterior coat of the corolla which is furnished with these organs. Were this outer membrane the reflected limb of the corolla, the true situation of the glands would be on its inner surface; but though appendages of the cuticle are not uncommon on the surface of both ligulate and tubular flowers of Composit&aelig;, I am not aware of their ever existing on that surface. The oblique mouth of these corollas and the constantly unequal divisions at its apex, of which one is always the largest, seem to point out the larger tooth as being analogous to the ligula of radiate capitula, especially as one of the four teeth is often suppressed. Lastly, the five nerves, which are most evident in L. lanata on the inner tube, are not visible on the outer; it is very difficult to trace their termination, but they do unite at the summit of the tube, forming