TRANSACTIONS OF THE SECTIONS. 71 



rigida, Eleocharis acicularis, var. elongata, Calamagrostis pyramidalis, Bromxis patulus, 

 commutafus, Cynosurus echinatus, Avena pratensis (i alpina, Lolium multiflorum, Equi- 

 setum Drummondii, Isoetes lacustris, Onoclea sensibilis. 



Description of Alexandria Imperatricis, a new Genus of Papilionacece. 



By the Chevalier Schomburgk. 



This tree, in appearance, is one of the most beautiful and gorgeous of the family of 

 Legurainosse, and was discovered by the author at the foot of the northern ridge of 

 sandstone mountains in the pluvial basin of the River Cuyuni, in Guiana, and reaches 

 a height of from 100 to 120 feet. The flowers are developed directly from the trunk 

 and woody branches, in large clusters, and the racemes, pedicles, and calyces are of 

 a rich crimson, the petals bright orange, striped with crimson, the vexillum of a deep 

 purple, and ascending. The pod is from eighteen to twenty inches long, and con- 

 tains several seeds. 



On a new Species of Barhacenia. By the Chevalier Schomburgk. 



This plant grows on the table land from which Mount Roraima rises. It reaches 

 frequently a height of ten or twelve feet, branching in a dichotomous manner, and 

 bears a number of flowers, which in their appearance are liliaceous, and five to six 

 inches long. They are, outside, of a delicately purplish hue, and deliciously fragrant. 

 It differs from the species of hitherto described Barbacenice, in possessing eighteen 

 fertile stamens. The difference in the number of stamens is not, however, allowed 

 to be generic in allied species of Vellozise, and, therefore, the author has placed this 

 plant with the Barbaceniae. 



On the Ophiocaryon Paradoxa, the Snake-nut Tree. 

 By the Chevalier Schomburgk. 



In a former communication Mr. Schomburgk had called the attention of naturalists 

 to the peculiar seed of this tree. The seed is covered over with a membrane, which, 

 on being removed, presents the embryo elongated and twisted in a spiral manner, so 

 as to give it the form of a snake. From a recent examination of the flowers of this 

 tree, the author had found that it belonged to the natural order Sapindaceae. The em- 

 bryo is twisted in other members of this order. 



On the Calycophyllum Stanleyanum. By the Chevalier Schomburgk. 



There are several genera of the natural family of Rubiacese, as Calycophyllum, 

 Musssenda, Pinkneya, &c., where one of the teeth of the cah'x expands into a coloured 

 petioled leaf, of a membranaceous texture. In this tree it is very remarkable ; and 

 as these bractUke organs are of a rose colour, they give a very beautiful aspect to the 

 forest where they grow. This appendage only grows after the flower has dropped 

 off, and developes itself with astonishing rapidity. The tree grows on the banks of 

 the rivers Rupununi and Takutu, in the third parallel of north latitude. 



Description q/"Lightia lemniscata, a new Genus of the Family ButtneriacecB, 

 By the Chevalier Schomburgk. 

 The Buttneriaceae are very common in Guiana, and in some districts the author 

 met with wbole forests of the chocolate nut tree, a plant belonging to this family. 

 The Lightia belongs to this family. The great peculiarity of the plant is, that the 

 petals have an elongated appendage, which hangs down from the cluster of flowers 

 like ribbons, and hence its specific name. This tree attains a height of twenty or 

 twenty-four feet, and produces its flowers directly from the stem, below the axis of 

 fallen leaves. Only three specimens of this tree were discovered in Guiana by Mr. 

 Schomburgk. 



