120 Mr Don o« the Characters and Jffi-nities 



longing to separate families ; but, I trust, the above description 

 will establish their intimate affinity, and prove that they belong 

 to one and the same family. Persoon had referred Pineda to 

 Homalium, and M. Decandolle has adopted this indication of 

 affinity, but has very properly retained it as a separate genus. 

 . In the arrangement of Azara, however, he has been less fortu- 

 nate, as he has followed the suggestion of M. Kunth, who had 

 proposed to place it among the Bixince^ or Prockiaceas, a name 

 which I greatly prefer, as being derived from a genus that af- 

 fords a much better idea of that order than Bia:a, which may 

 be considered as an aberrant member of it. The valvular aes- 

 tivation of calyx is not general throughout TillacecE, for in some 

 plants, clearly referable to that family, the margin of the lobes 

 is folded inwards, and in Sloanea dentata and emarginata the 

 lobes are slightly imbricated, and certainly decidedly so in the 

 genus Trichocarpus. The large rough prickly capsule of Blxa,^ 

 and the entire habit of the genus, correspond so exactly with 

 Sloanea, that they may very properly be considered as forming 

 the connecting links of the two families ; and as a further proof 

 of their close relationship, I may adduce the thickening of the 

 petioles near the insertion of the leaf in both genera, — a circum- 

 stance which is not found in any of the other genera that have 

 been referred to the ProcMacecB, although frequent in Tiliacece. 

 Some analogies in structure might be pointed out between Proc- 

 Macece and Cistince, on the one hand, and between HomalincB 

 and PassiJloretE, on the other, but in neither case amounting to 

 an indication of affinity. Neillia, formerly referred by me to 

 the SpircBocecB^ may be regarded as forming the rudiment of a 

 distinct group, more intimately allied to Homalinee, being chief- 

 ly distinguished from the former by the presence of petals, and 

 by the very reduced number of its pistilla, which are uniformly 

 solitary. The Abatia of Ruiz and Pavon, which M. Kunth has 

 doubtfully referred to his Bixince, appears to me clearly to be- 

 long to Salicaria, with which family it corresponds, in the seeds 

 being destitute of albumen, and in its opposite leaves clothed 

 with tufted pubescence, as is often the case in Cuphea^ and some 

 other genera of the same natural family. The following de- 

 scription of this curious genus will show these affinities in a clearer 

 point of view. 



