TO BOTANY. 19 



Variations of an INVOLUCRUM. 



The preceding varieties of the Calyx chiefly re- 

 spect a ^Perianthium. An Involucrum is either mo- 

 nophyllous, as in Bupleurum ; diphylfaus, as in Eu- 

 phorbia; triphyllous, as in Butomus and Alisma; 

 tetraphy lions, as in Cornus ; ptint aphyllous, as in 

 Daucus ; or hexaphyllous, as in Haernanthus. 



Variations of a SPATHA. 



A Spatha is either monophyllous, as in Narcissus ; 

 diphylbus, as in Stratiotes ; or imbricate, as in Musa. 



CHAP. XII. 



/ 



OF THE DIFFERENT STRUCTURES OF THE COROLLA. 



THE variations of the Corolla in respect to Num- 

 ber concern either Petals, or Laciniae, segments : 

 the variations of the Nectarium shall be given sepa- 

 rate. 



The. Corolla, in respect to its Petals, is either 

 monopetalous, or consisting of one Petal, as in Con- 

 volvulus and Primula ; dipetalous, of two, as in Cir- 

 csea and Commelina ; tripetalous, of three, as in A- 

 lisma and Sagittaria ; tetrapetalous, of four, as in the 

 class Tetradynamia ; pentapetalous, of five, as in um- 

 belliferous plants* ; hexapetalous, of six, as in Tulipa, 



* The umbelliferous plants are in the order Digynia, of the 

 class Pentandria. 



