BOTANY. 387 



describe briefly the two great systems of classification of plants, 

 which have prevailed in recent times. It was known, before the 

 time of Linnaeus, that the seeds of plants cannot be perfected from 

 the pistil alone, but require the agency of the pollen, or pulverulent, 

 fertilizing substance, from the stamens. Thus, if we cut off the tops, 

 or staminate flowers of Indian corn, before the pollen has fallen on 

 the silk of the ears, these latter, which contain only pistillate flowers, 

 will not fill out with kernels. Hence, those alone are called perfect 

 flowers, which contain both stamens and pistils; and the importance 

 of these organs induced Linnreus to make them the basis of his 

 artificial system of classification. In this system, the classes and 

 orders are founded on the number, positions, and other relations of 

 the stamens and pistils. 



The first ten classes are Monandria, having one stamen ; Diandria, 

 two ; Triandria, three ; Tetrandria, having four equal stamens ; 

 Pentandria, five ; Hexandria, six ; Heptandria, seven ; Oclandria, 

 eight ; Enneandria, nine ; and Decandria, having ten stamens. The 

 llth class, Icosandria, has more than ten stamens, inserted on the 

 calyx ; and the 12th, Polyandria, has the same, but not situated on 

 the calyx. The 13th class, Didynamia, has two long stamens and 

 two short, with labiate flowers ; and the 14th, Tetradynamia, has 

 four long, and two short stamens, with the flowers cruciform. The 

 1 5th class, Monadelphia, has the stamens united by their filaments, 

 in one set; and the 16th, Diadelphia, has them in two sets, with 

 papilionaceous flowers. In the 17th class, Syngenesia, the flowers 

 are compound, and the florets have their stamens united by the 

 anthers. The 18th class, Gynandria, has the stamens growing on 

 the pistil, and separate from the corol. The 19th class, Moncecia, 

 has the stamens and pistils in different flowers, but on the same 

 plant ; while the 20th, Dicecia, has them not only in separate 

 flowers, but on separate plants. In the 21st class, Cryptogamia, 

 these organs are either wanting, or invisible, or very caduceous. 



In the first twelve classes, the orders are founded on the number., 

 of pistils, whether with styles, or only with sessile stigmas. These 

 orders are monogynia, having one pistil ; digynia, two ; and so 

 on, following the Greek numerals, to decagynia, having ten, and 

 polygynia, having more than ten pistils. The 13th class has two 

 orders, gymnospermia, with naked seeds ; and angiospermia, 

 with the seeds in a capsule. The orders of the 14th class, are 

 siliculosa, having round pods ; and siliquosa, with pods long and 

 narrow. In the 15th, 16th, 18th, 19th, and 20th classes, the orders 

 are distinguished by the number of stamens, and have the same 

 names as the first twelve classes ; but in the 17th class, the orders 

 are sequalis, having all the flowers perfect; superflua, having the 

 disk or central florets alone perfect ; the ray florets, if any, being 

 pistillate ; frustanea, having the disk florets perfect, but the ray 

 florets neutral ; necessaria, having the disk florets staminate, but the 

 ray florets pistillate or fertile ; and segregata, having a separate 

 perianth, or calyx, for each floret, as well as for the whole flower. 

 The 21st class is divided into the natural orders of filices, or ferns ; 

 musci, or mosses ; hepaticse, or liverworts ; llchenes, or lichens, 



