134 Linnaean Society. 



STEMOPTERA. 



Perianthium ovario adnatum, supra Hberum, subinfundibuliforme : fauce 

 turgida sacculis 3 interioribus auct& : limbo 6-partito, laciniis acutis, 

 aestivatione marginibus induplicatis, 3 alternis brevioribus. Stamina 

 3, fauci adnata : Jilamentis complanatis, e margine sacculorum orienti' 

 bus bifurcatis, ramulo singulo antherifero alato. Ovarium turbinatum, 

 1-loculare, placentis 3 parietalibus. .S^^/ms longitudine staminum. Stig- 

 mata 3, recurvata, apice glandulifera. Capsula 1-locularis, polysperma, 

 subtrivalvis, apice 3-fisso dehiscens. Placenta 3, parietales. Semina 

 numerosissima, scobiformia, test4 iiucleo vix excedente, reticulata, are- 

 olis elongatis obliqu^ dispositis. 



Plantae (brasilienses) rhizocarpecBy radice Jibrosd. Caulis erectus, snhdi- 

 chotome ramosus, ramis subflexuosis, pallidis, subpurpurascet/libus. Fo- 

 lia pauca, sessilia, erecta, bracteiformia, pallida. Inflorescentia fermi- 

 nalis, uniflora. Flores cceteris majores, ebracteati, purpurascentes, Ap- 

 terioe Nutt. hand absimiles, 

 1 . Stemoptera lilacina. — In uliginosis ad Serra dos Orgaos Prov. Rio de 



Janeiro. 



All the species are described at length in the paper, and their cha- 

 racters are further illustrated by drawings, with details of the parts 

 of fructification. The author remarks that upon the same principle 

 that Apostasiacea have been separated from OrchidecB, and Xyridecd 

 from Restiacea, these plants ought to constitute an order distinct 

 from Burmanniacene ; but the difference between the unilocular cap- 

 sule with parietal placentation and the trilocular capsule with axile 

 placentation, which at first sight seems to offer a wide and well- 

 founded distinction, appears of less value when we consider that 

 the extensive order Gentianece presents similar differences, toge- 

 ther with every possible gradation of transition from one extreme 

 to the other. He therefore inclines to the view of preserving all 

 within the natural order Burmanniacea, dividing it into two sub- 

 families, viz. 1. Burmanniece, which will contain only the single 

 genus Burmannia (and perhaps the Gonyanlhes of Blume may be 

 found to belong also to this section) ; 2. Dictyostegea, com- 

 prising Dictyostega, Cymbocarpa, Stemoptera, Apteria, Gonyanthes, 

 and Gymnosiphon. He then proceeds to show the close affinity which 

 Burmanniacece bear to Orchide^e, which often also present nearly a 

 naked stem, with imperfectly developed leaves, and instances are 

 moreover known in which they exhibit three distinct stamens and 

 three stigmata : they have also an unilocular ovarium, with parietal 

 placentation ; there exists also a close resemblance in the structure 

 of the walls of the capsule, and there is hardly any difference in the 



