Dec. 1893.] BOTANICAL SOCIETY OF EDINBURGH. 71 



Celtis tala, Gill. 



Hab. — Fortin Page. Frequents the edges of the monte. 

 Fl. 26 th Sept. 



Prov. Arg. Tala. 



A straggling shrub some 5 feet in height, characterised 

 by its stiff rectangular spinescent branching. Fruit edible. 



QUERCUS sp. 



Hab. — Eio Pilcomayo. Frequent in open woodlands. 



This is, perhaps, the most interesting plant in the 

 collection from a geographical point of view, but the 

 material is too poor for its determination (X. E, Brown). 



Brassavola perpjxii, Lindl. 



Amongst the plants collected at Fortin Page was a fine 

 Epiphytic orchid with white flowers, apparently belonging 

 to Brassavola, or some allied genus. Its stems creep along 

 the branches of its host. Its leaves are elongate cylind- 

 roidal in form, with a deep groove along the upper surface. 

 Flowers numerous. The three sepals are linear and 

 colourless, as are the two smaller petals. The anterior 

 petal is broad, expanded, and white in colour ; basally its 

 edges curl upwards, so as to fit round the edges of the 

 hood-like column, and with it to form a funnel leading 

 into the nectary tube. This latter is about two inches in 

 length, so that probably lepidoptera, and from the white 

 colour of the flowers probably night-flying lepidoptera, 

 Uiake most use of the honey. The upper margin of the 

 mouth of the nectary tube is continued into the hood-like 

 column, whose under surface is deeply concave to form 

 the large somewhat conical stigmatic cavity. The inner 

 surface of this is smeared with sticky cement. Below, 

 this cavity is freely open : while above and distally its 

 roof projects downward somewhat, and ends in several 

 comb-like teeth. As it were, completing the hood distally 

 is a large cushion-like structure, which is loosely held in 

 position in a socket-like cavity by the downwardly pro- 

 jecting teeth before alluded to. This cushion has loosely 

 embedded in it the eight poUinia, and its posterior aspect 

 is smeared with a sticky cement. If a slender object is 

 inserted into the nectary tube and withdrawn, it rubs 

 against the downwardly projecting edge of the cushion, and 



