DECANDR1A, in botany, the name o the tenth class in Linnmus s system, con sisting of plants, whose flowers, as name imports, are furnished with ten sta mina or male organs. This class, as well as the other classes in Linnmus's method that are compounded with a numeral, has another' character, which is not expressed in the title, viz. that the flowers are all hermaphrodite, that is, have both stamina and pointels, which, according to our akt thor, are the male and female organs of generation within the same covers. In this respect, the classes in question differ from the Moncecia and Dicecia same author, in which the male and female or gans are separated ; being placed, in the former, upon different parts of the same plant : in the latter, upon distinct plants. This observation merits attention, be cause character, which is the subject of it, is indispensably necessary ; and a plant having ten, or any number of stamina, is not on that account to be referred to its respective numeral class, unless both male and female organs are found contained within the covers of the flower. To take 'an example from the class which we are now considering ; the flowers of the cu rious exotic, papaw, or popo-tree, have ten stamina ; and yet the plant cannot be arranged under the class Decandria, be cause the male and female parts are not only placed within different covers, but likewise produced upon distinct plants : the popo seed ripened by the female flow ers producing both male and female trees.
Besides the sexes of the flowers, it is ne cessary that the stamina be of an equal length, and distinct ; that is, neither join ed at the bottom nor top ; circumstances, which would remove the plants in which they are found, to classes whose es sential character is no ways connected with the number of the male and female organs.
The Orders- or secondary divisions in this numerous class are five, and take their name from the number of styles, or females organs. Praxenilla, lignum vita, dwarf rose-bay, and strawberry-tree, have one style; soap-wort, and carnation, have two; cucubalus, viscous campion, and sand-wort, three ; hog-plum, navel-wort, and house-leek, five ; neurada, and Ame rican night-shade, ten.
Decandria is likesvise the name of an order Or secondary division in the classes Monadelphia, Diadelphia, Gynandria, and Dicecia, in all which, the classic character being unconnected with the number of stamina, that circumstance, properly enough, serves as a foundation for the secondary or subordinate division.