56 JESTIVATION AND ITS TEBMINOLDGT. 



Linnocus made no use of restivatiou as a character. Nor iliil 

 Jussicu, except merely that in his " (iencra Plantarum/' the petals of 

 Malvaviscus are said to bo coyivolute. 



In Do Candolle's " Theorie Elementaire," 1813— a still unsur- 

 passed treatise, upon which, next to the *' Philosophia Botanica," our 

 botanical glossology rests — neither the word a:;stivation, nor its 

 synonym, prefloration, is mentioned, and even vernation or prefoliation 

 is equally omitted. 



But the history of restivation as a botanical character began in a 

 work published three years earlier, viz., in R. Brown's " Prodromus 

 Flonc Nov. HolL," 1810. The preface notes that it was first accu- 

 rately observed by Grew. In it Brown defines only the valrate mode, 

 " ubi margines foliolorum vel laciniarum intcgumenti invicem appli- 

 cati sunt, capsular valvularum in modum." In the body of the work, 

 wherever it is important, the aestivation is noted as vallate, imbricate, 

 plicate, induplicate, &c.; and the open ajstivation {aperta) is named by 

 him in a subsecjucnt paper. 



Being the fu'st to employ aestivation systematically, and to develop 

 its value, Brown's terminology for its modes may well be considered 

 authoritative. And so indeed it is, as far as it goes. But he did not 

 make one important distinction, viz., that between our I. and II. 

 Imbricate, in his use, comprises all kinds of overlapping, that of the 

 corolla of Apocynecc and of a Gentian, as well as tliat of a Primrose. 

 Ho must have not only noticed the difference, but also appreciated its 

 general importance, notwithstanding the occasional passage of the one 

 into the other. He must have also observed that in many cases, as in 

 Aselepias, for instance, the mode II. passes into mode III., the valvate, 

 and may possibly have discerned that under a phyllotaxic view these 

 are more nearly related than either is to mode I. I find, however, 

 only one instance in which he has indicated the distinction, viz., in 

 the character oi JBurchellia, furnished to the "Botanical llegistcr," 

 t. 435, 1820. Of its corolla it is said : " rcstivatione mutuo imbricata 

 contorta." The phrase is interesting, as it seems to recognise the 

 distinction between the mode of overlapping (which is that of our 

 mode II.) and the torsion, which only now and then accompanies it. 

 Looking over the **Planta3 Javanicae Kariores " to sec if there is any 

 later use, I find no instance in which Brown has occasion to speak of 

 this mode II. ; but it occurs in the portion of his associate, Mr. 

 JJennett, who (on p. 212) describes the petals of Soncrila as "aestiva- 

 tione convoluta.'" Had this term been thus employed by Brown 

 himself, and at an earlier date, I should regard the terminologj- of 

 these tlireo modes of aestivation as settled, viz. : I. imbricata, II. 

 convoluta, III. vahata. The first and the third are establislied beyond 

 question, although somewhat remains to be said about the first. 



But meanwhile another use has prevailed as respects the second. 

 In Do Candolle's " Prodromus," tlie first general or considerable work 

 after Brown in Avhich terms of aestivation are employed, this mode is 

 almost uniformly characterised as eofitorta. I cannot at this moment 

 trace the term to its origin. It was probably suggested by the name 

 Contortce, said to have been given by Linn:cus to the Apocyneous 

 natural order ; and it seemed appropriate to the instances in which 

 the strong convolution of rounded petals, as in Oxalis, or their lobes, 



