458 



PART IV. CLASSIFICATION. 



The individual leaves of the perianth may be either perfectly 

 separate (eleutlieropeialous or polypetalous corolla, eleutherosepal- 

 ous or polysepalous calyx), e.g. Ranunculus ; or they may cohere 

 from the base upwards, so as to form a longer or shorter tube, 

 which divides at its upper end into as many teeth or lobes as there 

 were originally leaves (gamosepalous calyx, gamopetalous corolla) 

 (Fig. 274 A B C c and B k) ; e.g. the Primrose and the Tobacco 

 plant. In Dianthus (the Pink) the sepals alone are coherent, as 

 also in Daphne (Fig. 274 Z>) where the corolla is absent. More 

 rarely all the leaves of the perianth cohere to form one tube, e.g. 

 the Hyacinth and allied genera ; the six lobes of the tube corre- 

 spond to the three 

 sepals and the three 

 petals. The simple 

 perianth also may con- 

 sist of separate leaves 

 (eteutlieropliyllous or 

 polypliyllous peri- 

 anth^, e.g. Amarantus, 

 or the leaves may be 



k 

 



coherent (gamophyl- 

 lous\ e.g. Aristolo- 

 chia. 



D 



FIG. 274. Cohesion of sepals and petals. A Flower of 

 Convolvulus arvensis, with a funnel-shaped corolla (c) ; and 

 a 5-partite calyx (k). B Nicotian* Tabacum, with a 5-cleft 

 calyx (it) ; tubular corolla (r), with a distinct 5-toothed 

 limb (). C The rotate corolla of Sambucns. D Gamose- 

 palous calyx of Daphne Mezereum ; r the tube ; s the limb. 



The degree of division 

 presented by gamophyl- 

 lous perianths into 

 teeth or lobes is indi- 

 cated by the same terms 

 which are used in de- 

 scribing the incision of 

 the leaf-blade (page 37). 

 The form of the gamo- 

 petalous corolla may be 



campanulale, as in the Campanula ; funnel-shaped (or infundibuliform), as 

 in the Bindweed (Fig. 274 A) ; rotate, as in the Elder (Fig. 274 C). The 

 upper and lower portions may frequently be distinguished, the lower as 

 the tube (Fig. 274 B r), the upper expanded part as tlie limb (Fig. 274 B s). 

 Other peculiarities of form are connected with the symmetry of the flower 

 (page 453). 



The petal frequently consists of two parts, the daw and the 

 limb, as in the Pink (Fig. 275 A B). The Corona (paracorolla) 

 in the Narcissus and Lychnis is formed by ligular outgrowths 



