OF PLANTS CALLED COMPOSITE. 269
Compositse. 1 It appears also that he is not aware of any exception to it in the class. I have however, in a different part of the same essay, noticed one exception existing in Chuquiraga, and I have since found another in Corgmbium. In both these genera the aestivation is induplicate, that is, the margins of the segments are doubled in, so that in the unexpanded state none of them are visible. I have in the passage referred to observed that the valvular and indu- ess plicate modes of aestivation easily pass into each other, merely by an addition or abstraction of the elevated mar- gins of the laciniae : instances of their abstraction, and of the consequent conversion of the induplicate into the val- vular mode, occur in several Goodenovise, and in some Convolvulaceae and Solanaceae ; while CJtuqitiraga and Co- rgmbium are examples of their addition in an order where they are generally wanting.
My third remark is entirely borrowed from Schkuhr, 2 who states that in all Cichoracece or Ligulata? the pollen is
1 Since this paper was read, M. Cassini has published his memoir (in the Journal de Physique for February 1816), in which he states the same aestiva- tion to exist in certain other families, namely, Campanulaceae, Lobeliaceae, and Rubiaceee. This observation, if applied to the whole of these families, as is evidently the author's intention, is correct only with respect to Campanulaceae, from which I have separated Stylideae as a distinct order, partly, as I have stated, on account of its imbricate aestivation. In a considerable part of the Lobeliaceae of Jussieu, which includes my Goodenoviae, the aestivation is not valvular but induplicate : and though in Rubiaceae the valvular mode is very general, there are many remarkable exceptions to it, as Gardenia, Ixora, Pavetta, Coffea, and several other genera, where it is unilaterally and obliquely imbricate, as in most of the Apocineae, with which Linnaeus united them under the name of Contortae, derived from this very circumstance. On this subject I may be allowed further to remark, that M. Cassini, who in the memoir now cited has repeatedly asserted his claim to the priority of the observation on the disposi- tion of vessels in the corolla, has in treating of its aestivation omitted to notice what had been already published respecting it in my essay above quoted, where I conclude he must have seen my observation, as he refers to the sentence con- taining it. The aestivation of corolla in Compositae is also noticed in the ob- servations on Brunonia, contained in my Prodromus Florae Novae Hollandise, which I suppose he has not seen : I may therefore, for the general importance of aestivation of calyx and corolla in affording characters both for Orders and Genera, refer him to almost every page of the same work, and to its preface, for an observation on the degree of attention that had been previously paid to this point of structure, which will enable him to correct in some measure his own remark on the subject.
2 Botanisches Handbuch 3, p. 8.
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