Definitions. xxxiii 



salver-shaped when the lower part is tubular and the lobes spread out 

 horizontally, as in Vinca rosea and the English periwinkles ; funnel- 

 shaped when the tube broadens from the bottom and the lobes 

 expand more or less horizontally. 



25. The commonest form of irregular monopetalous corolla is 

 two-lipped, or bilabiate, when the limb separates into two parts, 

 something in the way of a mouth with lips, as in the various species 

 of Antirrhinum and Salvia. In this case we speak of the upper and 

 lower lip of the corolla, these lips being generally lobed or toothed ; 

 of the palate, which is the part, often raised and not unfrequently 

 spotted or hairy, just within the lobes of the lower lip; and of the 

 throat, which is the entrance to the tube. 



Note. The term two-lipped is also applied to some polypetalous 

 corollas, if arranged so as to give that appearance, and also to the 

 calyx of many plants. 



A petal is said to be clawed when its lower part is suddenly nar- 

 rowed into what to some extent corresponds to the petiole of a leaf, 

 as in the genus Lagerstrcemia : spurred when it is produced downwards 

 into a narrow cylinder or spur : saccate when expanded into a little 

 bag or sac. 



26. The arrangement of the petals in the unopened flower (often 

 apparent also after it is opened) is called the (estivation, and some- 

 times requires to be noticed. If the edges of the different petals 

 meet evenly the aestivation is said to be valvate, if the petals much 

 overlap each other it is imbricated (this term is also much used with 

 reference to bracts) ; if the petals are twisted together, it is twisted. 

 When four opened petals are so shaped and arranged as to form a 

 cross, they are called cruciate. 



27. In many flowers either the calyx or corolla is wanting j the 

 single floral envelope that exists is then generally called the perianth ; 

 its divisions are called sepals, as if it were the calyx. In some cases 

 (e.g. orders Liliacece, Iridacece, etc.), though there is both calyx and 

 corolla, yet from their being both coloured, and otherwise very much 

 alike, the whole is often called the perianth. 



28. When there are six or more separate petals (whether with or 

 without calyx) they are sometimes so disposed as to be in two or 

 three different rows, one outside the other ; they are then said to be 

 in two or more series, or rows. This term is applied also to sepals, 

 bracts, etc. (see especially order Composite). Flowers, as roses, etc., 

 which by ^cultivation or otherwise develop several rows of petals 

 instead of stamens, are called double. 



29. Stamens and Pistil. The stamens and pistil, being the male and 

 female organs of generation or reproduction, are really the most 

 important parts of the flower, and occupy the centre of it, though 

 they are by no means the most conspicuous parts. The modern view 

 is to look on the calyx and corolla as meant mainly to protect these 

 more important organs while forming, and to promote reproduction 

 by means of insects when the stamens and pistil are mature. 1 



A flower that has no pistil (or female organ) is called a male flower ; 



1 On this subject the unscientific reader may be referred to the 

 works of Sir John Lubbock and Mr. Grant Allen. 



