312 MB. G. BENTIIAM ON OECIIIDEiii. 



appears to be almost or wholly deficient, which would bring 

 the plant nearer to the Dendrobiese, where, however, the Epiden- 

 drum-Uke union of the labellum with the column is as yet unknown. 

 The place of the genus can only be determined when further 

 specimens shall have come to hand. PleurantUum, Lindl. 

 (referred by him as a section to Epidendrum), five or six species, 

 has the characters of Epidendrum or almost of Ponera, except that 

 the short racemes or clusters of small flowers are sessile, or nearly 

 so, in the axils of distichous leaves, an inflorescence totally at 

 variance with that of the rest of the subtribe. 



The normal genera of the subtribe form three series, the first 

 eight of them having four pollen-masses only, without any trace of 

 the upper series, three (Lceliopsis, Tetramicra, and Brassavola) 

 in which the upper series is present, but much smaller than the 

 lower, and three (Lalia, SchomlurgJcia, and SojjJironilis) in which 

 the two series of four each are equal or nearly so. But these 

 distinctions are artificial and not always absolute, although great 

 importance has sometimes been attached to them. 



Diacrium, Lindl. (referred by him as a section to Epidendrum), 

 founded on Epidendrum Ucornutum, Lindl., contains four 

 described species or marked varieties, in which the peculiar 

 bicornute labellum, neither aduate to nor parallel with the column, 

 gives the flower a very different aspect from that of the true 

 species of Epidendrum, and cannot be included in them without 

 doing violence to the generic character. 



Isochilus, Br., limited to the original 7. linearis and three or 

 four species recently added to it, has a very peculiar habit, a free 

 labellum, and a few other distinctive characters of minor import- 

 ance. The other species enumerated in Lindley's Genera and 

 Species of Orchidea 1 have since proved to belong to various other 

 genera. Eeichenbach found in I. linearis six pollen-masses, each 

 cell of the anther being divided into three compartments. This 

 must have been in some abnormal individual. I have repeatedly 

 examined both fresh and dried specimens, and have always found 

 the normal four in a single series. 



Ponera, Lindl., including Tclragumestum, Reichb. f, altogether 

 four species, is specially distinguished from Epidendrum by the 

 flowers, usually small, showing a prominent mentum, the labellum 

 being adnate at the base to a basal projection of the column. The 

 inflorescence is also occasionally abnormal; the short, dense 

 racemes are, indeed, terminal on the year's shoot, but besides these 



