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ODONTOGLOSSUM citrosmum. 
Lemon-scented Odontoglossum. 
GYNANDRIA MONANDRIA. 
Nat. ord. Orchidacea: § Yandex. 
ODONTOGLOSSUM. Kunth. 
0. citrosmum (Lindl. Bot. Reg. 1842. misc. 68.) ; pseudobulbis subrotundis 
compressis lsevibus monophyllis, folio oblongo-ligulato obtuso racemo 
paulo breviore, sepalis oblongis obtusis petalisque conformibus subse- 
qualibus, labello unguiculato reniformi basi bituberculato, columnae alis 
lateralibus subtruncatis dorsaliq. rotundato denticulatis. 
Although such plants as this seem as if they weakened the 
genus Odontoglossum, on account of their similarity in habit 
to Oncidium, yet in truth they rather confirm that genus by 
showing that although the appearance of Oncidium may be 
assumed, yet the main points of structure remain unaffected. 
One of the most important of these points is the partial paral- 
lelism of the base of the labellum with the column, and the 
presence of a pair of parallel raised plates at that part. This 
occurs in the original Odontoglossum, and runs through 
all the numerous species published and unpublished with 
which I am acquainted ; and it does not occur in any Onci- 
dium. 
While however, notwithstanding its habit, this Odonto- 
glossum citrosmum confirms, rather than diminishes, the pro- 
priety of separating Odontoglossum from Oncidium ; it has a 
peculiarity of its own, which may possibly suggest to some 
minds the propriety of forming it and such plants as 0. brevi- 
folium and pulchellum into a separate genus, characterized by 
the presence of a toothed wing or membrane at the back of 
the anther ; and the similarity of these plants in habit might 
seem to justify the measure. In that case the generic name 
of Trymenium might be taken for them. I do not however 
