292 TRANS. ST. LOUIS ACAD. SCIENCE. 



covered a greater development of the genus, and Prof. Torrey in 

 his Botany of that Boundary (published in 1859) was able to 

 indicate five other species ; his account, how^ever, owing to an 

 insufficiency of material, is meagre an'd to some extent erroneous. 

 As far as I am informed, nothing has been added to our knowl- 

 edge of these plants in the sixteen years elapsed since his publi- 

 cation ; but in the last few years a quantity of new material has 

 been gathered, and, being placed at my disposal, has enabled me 

 to make a more thorough study of the genus. 



The Agaves are American plants, some of which became 

 known to Europeans since the discovery of America, and espe- 

 cially since the conquest of Mexico : the great Ag'ave Americana 

 is said to have been already in cultivation in Europe as early as 

 the year 1561 ; from the similarity of the spinous leaves they were 

 considered forms of the Aloes of the old word, and the name 

 "Aloe" has in popular language stuck to them to this day. 

 Linnaeus was the first to distinguish them, and in his Hortus 

 Upsalensis (1748), p. 87. he established the genus Ag'ave, and 

 enumerated the characters by which "these American plants" are 

 readily known from the true "Asiatic and African Aloes." He 

 adds that he has " named them Ag'ave, because that word indi- 

 cates something grand and admirable." It is interesting to 

 observe how even at that early date, when botanical geography 

 was not yet born, the geographical domains of these different 

 groups of plants struck the discriminating mind of Linnseus as 

 something remarkable and characteristic. 



The Agaves were first recognized as a distinct tribe by R. A. 

 Salisbury,* who united in his 12th order of Sarmetitacece Yucca 

 (with a "pericarpium superum") and Agave, Polyanthes and 

 others (with a "pericarpium inferum"), thus recognizing the 

 great resemblance of these plants, which we now place in differ- 

 ent but parallel families, just on account of the relation of the 

 ovary to the other parts of the flower. 



Other botanists! have appended them to the Amaryllida- 

 ceoe, but it must be confessed that they have only the inferiorj 



* Genera of Plants, ed. i865, p. 77. 

 t Endlicher, gen., p. 181 ; Kunth, Enum. J, p. 3i8. 



X In Agave tlie ovary is truly and entirely inferior, but the closely allied Polyanthes 

 shows a partly (about >i ) superior ovary. 



