GROSS ANATOMY OF THE AN0I0SPERM8. 307 



As to its stamens and pistils, the flower is 

 Bisexual or hermaphrodito, wlien stamens and pistils are pres- 

 ent ; 

 Uidsexual, when, of the essential organs, only the stamens are 



present (then staminate), or only the pistils (then pistillate) ; 

 Neutral, when both stamens and pistils are wanting. 

 Collectively, bisexual flowers are said to be monoclinous ; uni- 

 sexual flowers, diclinous ; while in those cases where some flowers 

 are bisexual and others unisexual they are, as a whole, said to be 

 polygamous. 



Diclinous flowers are further distinguished into 



Monceeious, when the staminate and pistillate flowers occur on 



the same plant, and 

 Diceaious, when they occur on different plants. 



The Perianth, or Floral Envelopes — In a large number of flowers 

 the parts of the calyx and corolla (sepals and petals) are distinct — i.e., 

 not at all united to one another ; such are said to be chorisepalous as 

 to the calyx, and clioripetalous as to the corolla. The terms x^oly- 

 sepalous and polypetalous are the ones most commonly used in English 

 and American books on botany, although they manifestly ought to be 

 used as numerical terms. Eleuilieropetalous and dialypetalous are 

 also somewhat used, especially in German works. 



Numerical Terms — The numerical terms usually employed are 

 mono-, di-, tri-, tetra-, penta-sepalous, etc., and mono-, di-, tri-, tetra-, 

 penta-petalou^, etc., meaning of one, two, three, four, five sepals or 

 petals respectively. Polysepalous and polypetalous are properly used 

 to designate " a considerable but unspecified number "of sepals or 

 petals. 



Union of Parts — In some flowers the sepals or petals, or both, are 

 united to one another, so that the calyx and corolla are each in the 

 form of a single tube or cup. This union of similar parts is called 

 coalescence. The teima gamosepalous axiAgamopetalous (or sympetalous) 

 are used in such cases. Monosepalous and monopetalous, still used in 

 this sense in many descriptive works, should be reserved for desig- 

 nating the number of sepals or petals in calyx and corolla respec- 

 tively. 



Adnatlon — Not infrequently the calyx and corolla are connately 

 united to each other for a less or greater distance. This union of 

 dissimilar whorls is termed adnation, and the calyx and corolla are 

 said to be adnate to each other. 



In the description of the parts of the perianth their form, size, sur- 

 face, color, and texture should be observed, using the same terms as 

 are used in case of the leaf. 



