IIG MU. G. BEN'XHAM 0>' MYJiXACEiE. 



also in other geuera, as, for Instance, in a few species of Uuca- 

 lyptiis allied to E. cornutus. 



In those Chamselauciese which have uniseriate stamens, normally 

 four times as many as the petals, the perfection of the whole, the 

 reduction of the alternate ones to staminodia, or the complete 

 disappearance of tlie latter, are fair generic distinctions. In 

 Thryptomene and Micromyrtus there are no staminodia; in both, the 

 stamens are either equal to or twice the number of the petals ; but 

 when reduced to the simple number they are in the one case op- 

 posite to, in the other alternate with the petals — a remarkable dif- 

 ference in genera otherwise so closely allied. In the other tribes 

 of Myrtacea?, the presence of staminodia or of abnormal stamens is 

 rare, and when it occurs, although a useful auxiliary, is scarcely 

 au absolute generic character. The y^tj remarkable stamens and 

 staminodia of JVapoIeona and Asteranthos will be referred to under 

 those genera. 



The anthers In Myrtacea? are, generally speaking, versatile, with 

 two parallel cells opening longitudinally, whilst in Melastomaceae 

 they generally open only in terminal pores, one to each cell, or 

 the two continued in a single terminal tube. But in both Orders 

 there are exceptions. In Myrtacese these exceptions are some- 

 times generic, sometimes sectional or specific only. The peculiar 

 anthers of Beaufortia^ Regelia^ PhyviatocarjynSy Calothamnns^ Ere- 

 mcea, and Oiistavia define genera separated also by other charac- 

 ters. So also the biporose and birimose anthers afford a good 

 distinction between Daricinia and Chaincelaucium^ whilst the same 

 character becomes sectional only in Verticordia ; and in the great 

 genera BcdcJcea and Eucalyptus^ the passage from the one to the 

 other is, in many cases, so gradual as to be scarcely available as 

 a positive specific character. The vast genus Euyenia^ amidst 



hundreds of species with the greatest uniformity in the structure 

 of the anthers, presents, as far as known, only one single excep- 

 tion : the anthers of E. Smithii are divaricate instead of parallel 

 one of the very few characters to distinguish this species from the 

 closely allied E. VentenatiL The appendages to the anthers of 

 some species have sometimes, as in CJirysorrlioe^ LindL, been pro- 

 posed as a generic character, which has entirely broken down on 

 further investigation. 



4. GryjECiuM. 



The perfectly inferior ovary (that is, its being adnate to the 

 calyx-tube up to the margin of its flat, concave, or convex summit; 



