Page:A Voyage to Terra Australis Volume 2.djvu/574

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560
APPENDIX.
[Botany of Terra Australis.

2dly. In Goodenoviæ the greater part of the tube of the corolla is formed by the cohesion of five laciniæ, the distinct inflected margins of which are in most cases visible nearly to its base; these laciniæ are in some cases unconnected, as in Diaspasis, and more remarkably still in Cyphia, which is actually pentapetalous. I have observed no such structure in Lobelia.

3dly. At the period of bursting of the Antheræ the stigma in Lobelia is almost completely evolved, and capable of receiving impregnation from the pollen of the same flower; the function therefore of its surrounding pencil, is similar to that of the hairs which are almost equally obvious in many Compositæ, especially Cinarocephalæ. On the contrary in Goodenoviæ the stigma at the same period, is hardly visible, and is certainly not then capable of receiving impregnation from the pollen of its proper flower; it is therefore either impregnated by the antheræ of different flowers, or in some cases at a more advanced stage by the pollen of its own antheræ, which is received and detained in the Indusium. To these arguments for the exclusion of Lobelia I may add that in the greater part of Goodenoviæ with dehiscent fruit, the dissepiment is parallel to the valves of the capsule, in which respect they differ equally from Lobelia and the valvular-fruited Campanulaceæ; and lastly, that many species of Lobelia as well as Campanulaceæ contain a milky juice of which there is no instance in Goodenoviæ. If therefore in Lobelia the pencil surrounding the stigma and the irregularity of the corolla, which, however, in some species is hardly perceptible, be considered as characters sufficient to separate this extensive genus from Campanulaceæ, it may form a separate order admitting, perhaps, of subdivision into several distinct genera.

I have formerly observed[1] that in two genera of Goodenoviæ, namely Eutholes and Velleia, the base of the corolla coheres with the ovarium while the calyx remains entirely distinct. This structure I had stated as being peculiar to these genera, and as in some degree invalidating one of Jussieu's arguments for considering the floral envelope of Monocotyledones as calyx rather than corolla. The fact, however, seems not to be admitted by Richard, who in the dissertation already quoted[2] describes what has hitherto been called calyx in Velleia as bracteæ: a view of the structure which in those species of that genus having triphyllous calyx, may appear
  1. Prodr. fl. nov. holl. 580.
  2. Annales du mus. 18. p. 17.