406 D. Prain — Some additional Leguminosee. [No. 2, 



clear why its use is preferred to that of Zoophthahnum ; the limits of § Zoophthalmum 

 DC and § Citta Bth. & Hk. f. are exactly the same. The name § Stizolobium is used 

 as in DC. Prodr., except that the species Mucuna gigantea is very properly excluded 

 from the section ; one of its varieties is placed in § Citta, while another variety of 

 the same species forms, along with M. macrocarpa, the § Carpopogon of Bth. & Hk. f. 

 The name Carpopogon is one that had been used in a generic sense by Roxburgh as the 

 exact equivalent of Mucuna Adans. or Stizolobium Persoon. Of the convenience of 

 the Genera Plantarum arrangement there can be no question, and the writer would 

 only propose to deviate from it to the extent of treating Stizolobium, in the mean- 

 time, as a subgenus rather than as a section ; the other two sections may be con- 

 sidered as together forming a second subgenus Zoophthalmum which, like Stizolobium, 

 will probably at an early date be once more treated as generically distinct. 



In the Flora of British India the arrangement advocated by Messrs. Bentham 

 and Hooker has been rejected entirely. The genus is subdivided into four groups, 

 to each of which is given the rank of a subgenus, and though, for three of the 

 proposed subgenera, the sectional names used by Bentham and Hooker are retained, 

 the definition and the limits of each of the three are altered. The section Citta is 

 divided into two subgenera, Amphiptera Bak. and Citta "Lour." The first of 

 these is distinguished by having wings down the sutures as well as plaits across 

 the pods, while the second has plaits but no wings. This subdivision does not 

 possess the advantage of being natural. Mucuna monosperma, placed in Citta, 

 instead of being wingless down the suture as is postulated in the definition given 

 of that subgenus, has wings that are sometimes as broad as those of M. imbricata 

 which is the type of Amphiptera. The only actual difference between the wings in 

 the two species is that in M. monosperma the plaits extend from the surface of the 

 body of the pod quite across the wings ; in M. imbricata the plaits do not extend 

 quite across the wings. The difference then, in place of being a subgeneric one, 

 is so slightly a difference of degree as to be, if taken alone, barely specific. The 

 pods of M. atropurpurea and also of M. biplicata, which is included in M. atropur- 

 purea in the F. B. I., do appear, when cursorily examined, to be wingless. But 

 closer inspection shows that they are winged, exactly as in M. monosperma, with the 

 transverse plaits continued across the wings, only the wings are here lobed to their 

 bases between each pair of plaits. 



The subgenus Carpopogon is confined to species broadly winged down both 

 Butures, thus limiting the subgenus to the single species M. gigantea. The Genera 

 Plantarum section of this name includes species that are no more than ribbed down 

 each side of the suture aud thus, naturally enough, includes M. macrocarpa, which 

 has long woody pods and has seeds with a circumferential hilum. But M. macrocarpa, 

 in spite of its circumferential hilum, is put in Stizolobium by the F. B. I. thus again 

 rendering the definition given in the Genera Plantaram inapplicable, since that 

 restricts to the section Stizolobium those species that havo a small hilum to the 

 seeds. Most unfortunately Mr. Taubert, in the authoritative Natiirlichen Pflanzcn.- 

 familien, has adopted the quite untenable divisions proposed in the F. B. I. For 

 not only is there no doubt that Bentham and Hooker are right in accommodating 

 M. macrocarpa and M. gigantea in the samo natural group, there is now equally no 

 doubt that M. gigantea cannot be separated from the natural group containing M. 

 imbricata and M. monosperma. The writer has collected, in the Andamans, specimens 

 of M. gigantea, some of the pods of which have ridges across the face in exactly 

 the position of the plaits in the other species. 



