150 MR. G. BEKTHAM ON MYKTACEJ::. 



author, however, subsequently (Linnsea, xxx. 713) acknowledged 

 that Lacerdcea was not really distinct from Britoa. 



Paty^a, Berg, is founded on a single Brazilian specieSj with the 

 habit and general character, as far as known, of Campomanesia, 

 but with the calyx-limb remarkably dilated at the base into five 

 protuberances, very prominent in the bud. It is doubtful whether 

 this peculiarity is of any more than specific value ; but as the ripe 

 fruit and seed are as yet unknown, and as the ovary requires 

 further investigation in more advanced specimens, we have retained 

 the genus until its real place shall be ascertained by the examina- 

 tion of the embryo. 



PsiDiUM, Linn., a large American genus, of which one or two 

 species have been long in cultivation in most tropical regions 

 under the name of Guava^ has been generally distinguished from 

 Myrtus and Eugenia by the valvate calyx, the 4- or 5-celled ovary, 

 and numerous small seeds. The first character, however, which 

 is still the principal one to separate it from Myrtus^ is to a certam 

 degree a mistake; the real calyx-lobes, when developed, are, as 

 in all other Myrtese, imbricate in the bud ; but they are very small 

 or even entirely abortive, and the undivided part of the limb, 

 closed over the petals and stamens in the bud, instead of dilatmg 

 as the flower opens as in Myrtus and Eugenia^ or becoming cir- 

 cumsciss round the base as in Galyptranthes and Acicalyptus, sph^s 

 longitudinally or bursts irregularly and remains persistent, the 

 parts having but rarely any regular relation to the number ot 

 sepals. The 4- or 5-celled ovary is also a general character, but 

 not quite constant, a few species having the number reduced to 

 2 or 3, as in Myrtus ; the number and size of the seeds is much 

 more variable than at first supposed. The embryo is that ot 

 Myrtus^ the habit somewhat different. The distinction from 

 Campomanesia has been already noticed. 



We propose reuniting with Psidium two of Berg's genera: — -l- 

 Acca^ a single Peruvian species (the two established byBerg,chiefly 

 on geographical grounds, prove to have both the same origin), wa^ 

 indicated by DeCandolle as a genus distinct from Eugenia^ under 

 which it had been published; but I can discover nothing in habit 

 or character to separate it from Psidium. 2. Calyptropsidium is a 

 Guatemalan species, which is unknown to us, except from Berg s 

 description. By this it appears only to differ from Psidium it. 

 that the calyx-limb, besides splitting longitudinally, is at length 

 more or less circumsciss at the base. 



Psiniorsis, Berg, and CALtcoLi>us,Berg, are two small genera, 



