26 BOTANY. 



penta-petalous corolla. A corolla, with more than one separate petal, is 

 known generally as poli/petaloiis ; it is gamopetalous or monopetalous when 

 the petals are united. The adhesion extends, in greater or less degree, from 

 the base to the apex. When the petals are similar and equal in size, the 

 corolla is regular ; otherwise, irregular. In monopetalous corollas, the 

 claws or inferior parts of the petals are usually united into a tube, crowned 

 by the limb, as in the calyx; the two portions are separated by the 

 throat. 



In REGULAR POLYPETALOus corollas wc havc the rosaceous, with five 

 spreading petals, without claws, and arranged as in the strawberry ; the 

 caryopJiyllaceoas, with five petals, with long, narroAV, tapering claws, as in 

 the pink ; the alsinaceous, where the claws are broader, with distinct spaces 

 between the petals ; cruciform, having four, often unguiculate petals, placed 

 opposite to each other, as in a cross (seen in the Cruciferge). 



Among IRREGULAR POLYPETALOUS corollas the most striking is the papi- 

 lionaceous, usually with five petals, one superior (or posterior) and larger than 

 the rest, called the vex'dlum ; two lateral, called alec ; and two inferior (or 

 anterior), partly or entirely covered by the alae ; often united into a single 

 piece, called the carina, or keel. 



Regular Gamopetalous Corollas. These are canipanulate, or bell- 

 shaped ; infundibuliform, or funnel-shaped ; hypocrateriforni, or salver- 

 shaped, where there is a straight tube, surmounted by a flat spreading limb ; 

 tubular, with a long cylindrical tube, apparently continuous with the limb ; 

 rotate, where the tube is very short, and the limb spreading. 



Irregular Gamopetalous Corollas. Conspicuous among these is the 

 labiate corolla, having two divisions of the limb, in the form of labia or 

 lips, the upper lip usually composed of two pieces, the lower of three, and 

 separated by a hiatus. The parts of the calyx follow the reverse order. 

 When tlie upper lip of a labiate corolla is much arched, and the lips separated 

 by a distinct gap, it is called ringent. When the lower lip is pressed 

 against the upper, so as to leave a mere rictus between them, the corolla is 

 personate or masked ; the projecting portion of the lower lip is called the 

 palate. When a tubular corolla is split up, so as to form a strap-like process 

 on one side, with several tooth-like projections at the apex, it becomes ligulate, 

 or strap-shaped. 



What are sometimes called nectaries in flowers, are most generally mere 

 modifications of the corolla or stamens. Sometimes they are constituted by 

 the separation of a layer from the inner side of a petal, which^may be known 

 by their being opposite to the segments of the latter. This process is called 

 unlining, or deduplication. 



The calyx and corolla, as just considered, constitute merely the external 

 envelopes of the flower, and may be absent without vitiating the fertility of 

 the plant. The essenticd organs of reproduction are the stamens and the 

 pistil. The latter, as the female organ, includes the ovary in which the 

 seeds are to be produced, while the former, supplying the functions of a 

 male, furnish a seminal matter to fertilize the ovules of the pistil. The 

 production of a perfect and reproducing seed requires that both be present. 

 26 



