64 PEOFESSOE LINT)LET*S NOTE ON PSETJDOCENTRUM. 



spondent Professor Jameson, there is one possessing so very extra- 

 ordinary a structure that it seems worthy of being brought sepa- 

 rately under the notice of the Society, although nothing more is 

 known of it than that it is a terrestrial plant from the valley of 

 Lloa, a couple of spikes of flowers having alone reached me. 



These spikes are dense, erect, cylindrical, 10 inches long, and 

 very slightly coated with minute distant hairs. A thin lanceolate 

 three-veined bract supports each flower, reaching beyond the 

 summit of the ovary. The flowers themselves are not unlike, in 

 general appearance, those of a minute Aconitum lycoctonum, being 

 furnished with what seems at first sight to be a slender curved 

 galea many times longer than the limb ; but upon dissection this 

 galea proves to consist of the two lateral sepals excessively pro- 

 duced at their base and forming a sheath, within which the labellum 

 lies concealed. Thus far there is nothing in the structure to 

 which a parallel may not be found elsewhere, as in Dendrobium, 

 Bifrenaria, Comparettia, and especially in Pelexia, a genus to 

 which the plant before us is nearly allied. But when the labellum 

 is examined, it is found to be extended within the fold of the 

 lateral sepals, not in the form of a spur arising from its base, but 

 in that of a long slender channeled body proceeding from its 

 point, the base of the labellum being acutely hastate. In other 

 words, the labellum is sessile, hastate, 3-lobed, with the middle lobe 

 extremely long, linear, channeled, and directed upwards between 

 the sepals which conceal it. In this manner the appearance of a 

 spur is produced without recourse being had to the arrangement 

 which occurs in every other genus of this large order, hitherto 

 described ; for which reason I propose the name Pseudocentktjm, 

 to which the following technical character may be added : — 



PsEUDOCENTEUM (Gcnus Ncotticarum PelexisB affine). Herba 



terrestris ; Spica elongata, densa, striata, cylindracea. 



Ovarium rectum. Sepaltim anticum parvum, lanceolatum, 

 patens ; lateralia dorsalia, multo majora, triangularia, basi in 

 canalem longum ascendentem arcuatum obtusum producta. P«- 

 tala lineari-lanceolata, apice recurva, sepalo antico breviora. 

 Labellum membranaceum, sessile, trilobum; lobis lateralibus 

 acutis hastam referentibus, intermedio lineari, canaliculato, 

 intra canalem sepalinum incluso eique aequali. Colnmna nana, 

 semiteres; stigmate depresso marginato, rostello acuminato. 

 Anthera dorsalis apiculata, bilocularis (?) ; pollinia 4, pulverea, 

 lateralia majora glandula parva oblonga. 

 Sp. 1. Fseudocentrum macrostachywm. Peru, Jameson. 



