A partial, secondary, or small involucre. See Illust. of Involucre.
                                                            
                                                     
                        
                                                
                        
                        
                            n. (L. involucrum, covering) a secondary involucre, as the bracts subtending the secondary umbels in the Umbelliferae.
                                                            
                                                     
                        
                                                
                        
                        
                            involucre of bractlets surrounding a secondary inflorescence such as the base of an umbellule.