251 



this plant captures insects that feed on its honey, as fol- 

 lows : — 



The Arauja sericofera of Brotero (Linn. Soc. Trans. Vol. 

 XII. p. 69, t. 4, 5,) is a Peruvian plant, belonging to the natural 

 order, AsclepiadacecE. It was received from Peru by Brotero 

 under the name of Apocynum Peruvianum, according to Dow, 

 who describes it in his System, Vol. IV. p. 149. It is also de- 

 scribed in De CandoUe's Prodromus, Part 8, p. 533, and also by 

 Martins and Zuccarini, Vol. I. p. 53, t. 32, the last authors giv- 

 ing it under the name of Physiantlius alhens, with an admirable 

 figure. It was named Arauja, after a Portuguese botanist of 

 some celebrity, Antonio de Araujo. 



The general descriptions of these writers give an accurate 

 account of its various parts, but the space allowed to it, or per- 

 haps a want of knowledge of the growing plant has not permitted 

 them to describe the curious trap which it offers to the insects 

 which feed on its honey. The tube of the corolla is swollen at 

 its base and constricted in the middle in a star-like form. The 

 five diverging cavities are exactly over the approximate horns of 

 the anthers. The horns are directly over the nectaries, so that 

 when the insect inserts its proboscis into the cavity, it is very 

 naturally thrust between these horns, which are hard and inflexi- 

 ble. On attempting to withdraw its proboscis, it becomes wedged 

 in between the anthers so tightly that the largest insects are fre- 

 quently held until they die and hang pendant from the flower. 

 There is no sensitiveness in the flower itself. The insects catch 

 themselves, and so often does this occur that a gentleman in New 

 York has obtained butterflies, bees, and a great variety of other 

 insects, enough to fill a large case, from the flowers of a plant 

 growing in his garden. 



De Candolle describes four species of the genus Arauja, one 

 of them being the A. alhens of Dow, which is different from the 

 Physianthus alhens of Mart. & Zucc. This latter now takes the 

 name of A. sericofera, and has a leaf quite smooth on the upper 

 surface, while the A. alhens is beset with scattered hairs, with a 

 downy corolla. The specific name of alhens is scarcely appli- 

 cable to any one plant of a genus which is always whiteflowered. 



