168 Podostemacea. 



is made to contain a very heterogeneous mass of species, his 

 three sections forming, in my opinion, three very distinct 

 genera, that is, three types of structure, differing both in 

 habit, and in the nature of their flowers. The last section, 

 Mourera, should alone belong to the genus, being well dis- 

 tinguished by its spicate polyandrous flowers. Marathrum 

 of Humboldt and Bonpland, forming the second section, is 

 also well characterized by its habit and definite stamens. 

 Neolacis of Chamisso, the first section, is more nearly related 

 to Podostemon, than to either of the other two sections.* 



By Endlicher Mourera is said to possess a perigonium 

 consisting of " Squamulae 2, collaterals, vel plures indefini- 

 te, verticillata? ;" and they are said to alternate with the 

 stamens. I regret that I do not possess a flower of any 

 published species of the genus, but judging from those of 

 an unpublished Marathrum, which exists in my Brazilian 

 Herbarium, and from what exists in Podostemon, these 

 scales I believe to belong to the same whorl as the sta- 

 mens. It is only in the genus Tristicha that a true perigo- 

 nium exists. Mourera was long known by the name of 

 Lacis, Schreber, in his edition of the Linnaean * Genera 

 Plantarum', having taken the unwarrantable liberty of chang- 

 ing many of the names of the genera which had been esta- 

 blished by Aublet : this too without any reasonable motive, 

 and without being acquainted with Aublet's plants further 

 than from his figures and descriptions. His name has thus 

 been branded with a stain, which, it is to be hoped will pre- 



* The great object of the classification of plants being to bring together those 

 which most nearly resemble each other, so that the student of Botany may, by 

 the contrast of their characters, be able not merely to distinguish one plant from 

 another, but to gain a knowledge of their structure from their written characters, 

 I firmly believe, that more doubtings, difficulties, and impediments have arisen 

 from the incautious grouping of plants together under a common character, taken 

 only from a few points of resemblance, than ever has resulted from an opposite 

 course. Every working Botanist, who like myself, is placed in circumstances 

 which necessarily confines him to a limited library, must have felt the truth of 

 this observation. 



