XXVI 



INTRODUCTION 



flower is sometimes called calycifloral, as if these parts sprang 

 from the calyx. 



The Calyx (from the Greek kalux^ a cup) is usually green and 

 leaf-like, though it may be petaloid, as in the Marsh-marigold. 

 Its sepals may be free {polysepaloiis) or united {ganwsepalous)^ like 

 a cup. In all hypogynous flowers it will be, as we have seen, in- 

 ferior, and in all epigynous ones, superior. In direction the sepals 

 may be erect, as in the Cabbages ; asce?idiiig, as in Mustard ; spread- 

 ing, as in Strawberry ; or reflexed, as in the bulbous Buttercup. At 

 their base they may be pouched, as in the two outer ones of most 

 Cruciferce ; or they may be spurred, as in one of those of the 

 Larkspur. Even when made up of five united sepals, the calyx 

 is often bi-labiatce or two-lipped, as in the Broom and the Sage. It 

 may be tubular^ as in Centaury ; tubular and plaited, as in Prim- 

 rose, folded so as to be star-shaped if cut across ; bell-shaped, as 

 in Henbane ; barrel shaped, or urceolate, and inflated, or separated 

 by some considerable space from the corolla within it, as in the 

 Bladder-campion ; or cylindric, as in the Carnation. In some 

 Composites and other flowers the calyx is replaced by a circle of 

 hairs called a pappus, which often enlarges in the fruit stage, as in 

 Thistle-down. In duration the calyx may be caducous, falling off 

 as the flower opens, as in Poppies ; deciduous, falling with the petals 

 and stamens when the seed is set, as in the Cherry ; or persistetit, 

 remaining in the fruit stage, as in the Strawberry. When persistent 

 it is generally marcescent or withered, as in the Hawthorn, Apple, 

 Medlar, and Gooseberry. 



The Corolla (" litde crown ") is the ring of more deHcate, or 

 petaloid, leaves within the calyx, which are usually 

 coloured — that is, not green — and often fragrant. 

 They are also usually attached by a narrower base 

 than the sepals, this being sometimes drawn out 

 into a long narrow portion or claw, as in the 

 Pinks, when the broader upper part is dis- 

 tinguished as the limb. If coherent the petals 

 are gajnopetalous and the united part forms the 

 corolla-tube, the junction of the tube with the 

 free limb being known as the throat. In the 

 Borage tribe the throat of the corolla is generally 



Clawed petal of a 

 Pink. 



furnished with little scales or swellings. If not 



coherent the petals are polypetalous, and this is a 

 discriminating character of great importance in the classification 

 of Dicotyledons, as also is their insertion, whether hypogy7tous, 

 per igy nous or epigynous, and, to a less extent, their symmetry. Of 

 polypetalous types the most important are the cruciform, consisting 



