386 



A TEXT-BOOK OF BOTANY. 



the gamopetalous corolla the lower united portion is known as the 

 TUBE, and the upper outspreading portion as the LIMB or " border." 

 The form of the calyx and corolla is quite characteristic for a 

 number of important families. In the Compositae there are two 

 characteristic forms of corolla, namely, the tubular in the disk 



FIG. 226. Apocynum androsamifolium: A, portion of a flowering branch; B, a flower 

 showing the short calyx tube and the corolla with more or less spreading lobes; C, longi- 

 tudinal section of flower: c, calyx teeth; p, corolla lobes; a, anthers; and p, ovary; D, 

 single stamen with long spurs (s). E, a flower of A. cannabinum showing the corolla with 

 ascending lobes. 



flowers and the ligulate in the ray flowers; in the Papilionatae 

 the corolla, from its fancied resemblance to a butterfly, is de- 

 scribed as PAPILIONACEOUS (Fig. 221, #) ; in the Labiatae the 

 petals are united into two lip-like divisions, and the corolla is said 

 to be BILABIATE (Fig. 223, F). There are two kinds of bilabiate 



