Ml*. J. Miers on the genus Salpiglossis. 29 



IV. — Contributions to the Botany of South America. 

 By John Miers, Esq., F.R.S., F.L.S. 



[Continued from vol. iv. p. 363.] 



Salpiglossis. 



Upon a former occasion (hvj. op. iii. p. 172) many reasons were 

 adduced to show why the tribe of the Salpiglossidece, as constituted 

 by Mr. Bentham (DC. Prodr. x. 190), could not be maintained, 

 and I proposed to limit that tribe simply to Salpiglossis, Browallia, 

 Leptoglossis, and a new genus Pteroglossis, all being distinguished 

 by their singularly dilated stigma and the peculiar mode of aesti- 

 vation of the corolla. A careful examination of Leptoglossis 

 schwenckioides has since then offered reasons for placing that 

 genus among the Petuniece. The Salpiglossidece, however, as 

 thus limited, are evidently most intimately allied to the Petuniecp, 

 agreeing with them in a somewhat similar form of stigma, the 

 development of their stamens, their capsular fruit, and the very 

 spiral form of the embryo in Salpiglossis, and differing from them 

 only in their didynamous stamens and the aestivation of the 

 corolla. The didynamous arrangement of the stamens does not 

 appear to me to offer a sufficient reason for keeping them in an 

 ordinal point of view apart from the Petuniece, and for retaining 

 them in the Scrophulariacece ; indeed in the Petuniece and Nico- 

 tianece, we find an evident tendency towards a didynamous struc- 

 ture, for one of the stamens is constantly shorter than the others, 

 which are in two pairs, while the anther of the fifth is always 

 somewhajt smaller, and frequently almost sterile ; and on the 

 other hand, I have observed occasionally in Salpiglossis a fifth 

 fertile stamen, showing a disposition to return to its normal con- 

 dition • and I have also before me an instance of a flower with 

 three pairs of stamens, varying in length, with a seventh shorter 

 one, the anther of which, though smaller than the others, is fer- 

 tile. The position of the Salpiglossidece in the natural system 

 appears to me therefore manifestly in the family which I propose 

 to call Atropacece, or if considered only as a suborder, Atropine®, 

 according to the arrangement there shown (loc. cit. p. 165). 



There is little in the genus Salpiglossis that calls for observa- 

 tion ; one peculiar feature however claims attention, the singular 

 form of its pollen-grains : these are comparatively large and rea- 

 dily distinguished under a common lens, each granule consisting 

 of four agglutinated spherical globules similar in form to the 

 simple pollen-grains of most Solanacece and Scrophulariacece : 

 three of these globules are on the same plane, the other being 

 superimposed in the centre, thus forming a sort of rounded tetra- 

 hedron, and they adhere so completely that they cannot be sepa- 



