344 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [Vol. 8, No. 4 



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and the validity of the names of later genera based on various species formerly 

 placed there need not be questioned. Subsequent alteration of the circumscription 

 of Chaetogastra by Naudin (1850) need not be considered here. 



Arthrostemma Pavon ex Don (1823) included present-day species of Arthro- 

 stemma, Mono chae turn , and Oxyspora. De Candolle (1828a) separated the genus 

 from Chaetogastra on the basis of its 4- rather than 5-merous flowers; in his am- 

 plification and modification of the circumscription of Arthrostemma, he included 

 there species now placed in Arthrostemma, Pterolepis , Castratella, Tihouchina, 

 Comolia, Monochaetum, and Brachyotum; Arthrostemma sect. II Brachyotum DC. 

 comprised four species, all now placed in Brachyotum, and one of which has been 

 designated in the current treatment as the genotype. 



Pleroma D. Don (1823) was composed entirely of species subsequently placed 

 in Tihouchina by Cogniaux (1891); De Candolle (1828a) altered the circumscrip- 

 tion of the genus in several respects and included questionably the Brachyotum 

 species described by Desrousseaux as Melastoma ledifolium. Using Cogniaux's 

 circumscription of Tihouchina, the changes in delimitation of Pleroma by Naudin 

 (1849) and Triana (1867, 1871) do not affect the status of the generic name Brach- 

 yotum, Naudin placed the Desrousseaux species in Lasiandra DC; in this genus, 

 De Candolle had included only species which were later placed by Cogniaux in 

 Tihouchina, so again Triana 's generic name is not affected nomenclaturally. 



Bonpland (1806-1823) lumped all the melastome species described by him into 

 two genera; the species later transferred to Brachyotum (by Triana) were placed 

 in the genus Rhexia, Rafinesque (1838) proposed the genus Bolina to replace 

 Bertolonia Raddi (1820) non Raf. (1818); he also transferred to Bolina species 

 now placed in Pterogastra and Centronia, as well as Rhexia (Brachyotum) conferta 

 Bonpl. Bolina should be typified by one of Raddi's species of Bertolonia (Lan- 

 jouw et al. 1952, App. I), and hence is superfluous, since Raddi's generic name 

 has been conserved (Lanjouw et al. 1952, p. 123). In addition, the calyx of Brach- 

 yotum confertum does not conform to Rafinesque 's description of "angular 5" 

 gonus" so this species would not be used to typify Bolina if only Rafinesque 's 

 comments, and not the synonymy listed by him, were considered. 



Rafinesque in the same publication added further complications to the validity 

 of the generic name Brachyotum by employing the name "Alifana (Ad)" and refer- 

 ring there "all the decandrous Rhexias or A. canescens, striata, lutescens, mon- 

 tana Raf. (Rhex. polypetala R.P.)&c." Al'dana may be rejected on two lines of 

 reasoning: (1) In referring to Adanson, Rafinesque was using a variant of Adanson's 

 genus Alifanus which was illegitimate since it was superfluous when published 

 (Lanjouw et al. 1952, Art. 73). Adanson (1763) included Rhexia L. under Alifanus 

 Pluk. Piukenet's name is pre-Linnean (1705) and Adanson therefore, from a mod- 

 ern viewpoint, should have used the Linnean Rhexia as the generic name; in this 

 connection, it should be noted that this publication of Plukenet was reprinted in 

 1769, with the addition of a/iother title page in front of the original one, but this 

 is not considered to constitute post-Linnean publication. (2) Alifana, if published 

 by Rafinesque, would be illegitimate since it would be a later homonym of Ali- 

 fanus Adans. which was based on a different type (Lanjouw et al. 1952, Art. 74). 

 But in fact, Rafinesque was not using a new name for the genus, as is shown by 

 his discussion under the genus and his not giving the derivation of the name as 

 he usually did for genera he was proposing. Any other interpretation of this no- 

 menclatural problem would make necessary a proposal for conservation of Brach- 

 yotum as a generic name since three of the species referred to Alifana by Rafin- 

 esque are currently placed in Brachyotum; the fourth, "montana Raf." is a dubi- 

 ous reference, perhaps to Rhexia polystachya Bonpl., since there is no "Rhex. 



