SPECIAL FORMS OF CALYX AND COROLLA 53 



Terms Indicating Cohesion or its Absence. — AVhen the petals are dis- 

 tinct the corolla is said to be Eleutheropetalous or Choripetalous. The 

 older but less desirable term is Polypetalous. When they are coherent, 

 the corolla is said to be Gamopetalous or Synpetalous, the older and 

 less desirable term being Monopetalous. Corresponding terms for the 

 calyx are Eleutherosepalous, Chorisepalous, or Polysepalous, and 

 Gamosepalous, Synsepalous, or Monosepalous. In the gamopetalous 

 and gamosepalous state the parts cease to be designated petals and 

 sepals, and are known respectively as Corolla-lobes and Calyx- 

 lobes. 



The relative altitude to which the cohesion is carried is indicated 

 by special terms. When existing at the base only, the circle is said to 

 be parted (Fig. 84) ; when extending about half-way up, as in Solanum, 

 Cleft (Fig. 92) ; when still farther, but yet leaving a considerable portion 

 ununited, as in Spigelia, Lobed (Fig. 97), and when having only traces 

 of the parts ununited. Toothed (Fig. 102). A peculiar form is that in 

 which the position of the parts is indicated by a mere waving irregular- 

 ity of the margin, as in the flower of Ipomoea (Fig. 91), which is then 

 said to be Sinuate or Undulate. The student must not fail to discrim- 

 inate between the entirely different senses in which these terms are 

 here used, in reference to the entire calyx and corolla, and as used 

 previously in reference to the margin of a single part thereof. 



Special Forms of Calyx and Corolla. — We must next consider certain 

 specific forms of the calyx and corolla as wholes, which are of very 

 great diagnostic value. That the form of a gamopetalous corolla is 

 determined by the form of the petals of which it is composed is readily 

 seen by comparing Figs. 18 and 98. In Fig. 18 we have a petal with 

 a long, slender claw and a broad limb. Several such petals united by 

 their edges must yield a corolla with a broad border supported upon a 

 long tube; just such a form is that represented by Fig. 98. Similar 

 results are shown in Figs. 97 and 99, and it is not difficult, on examining 

 these figures, to imagine the exact form of the component parts. In 

 Fig. 93 we have a union of somewhat broader petals, while those of Fig. 

 103 were so very short and broad as to have resulted in a saucer-shaped 

 corolla. 



Although such characteristic forms are most numerous among the 

 coherent class, they are not wanting among those in which cohesion 

 does not exist. Sometimes a non-coherent corolla will necessarily 

 assume such a form through the restraint exercised by coherent sepals. 

 At other times the form is entirely independent of such restraint. 



