PHANEROGAMIA : FLOWERS. 343 



described as corona? in the Stapelics and some other Asclepiadecea, 

 the nectaria of Ranunculus, Parnassia, &c. 



The corolla consists of one circle, rarely of two (three series in 

 Berberis) or more (four series in Nymphcea). In Monocoty- 

 ledons the number of members is equal to those of the calyx ; 

 in Dicotyledons, the number of five in a circle predominates, though 

 it is sometimes composed of two, of four, or of greater number (in 

 Dryas) (?). The number of members is equal to that of the calyx, 

 or greater ; very rarely indeed is it smaller ; this last case occurs 

 with Hibiscus. Suppression is not infrequent, and sometimes 

 involves all the foliar organs of a corolla at once (for instance, in 

 the summer flowers of many species of Viola, in Lepidum ruderale, 

 and some species of Acer). The coherence of organs in every way 

 is still more frequent ; never, indeed, with the calyx or the germens, 

 but frequently with the stamens. 



The corolla, whether with free or with coherent petals, may be 

 regular or only symmetrical. In the latter the bilabiate formation 

 is the most frequent, especially in five-membered circles, in such 

 a way that, according as the odd petal is on the upper or the under 

 side of the flower, the upper lip consists of three or of two petals. 

 In the latter case these two are very often little or not at all 

 coherent, as in Teucrium, the so-called radiated flowers of the 

 Composites (floribus ligulatis vel radiatis). Peculiar forms of sym- 

 metrical flowers are, for instance : the personate flowers (corolla 

 personata\ in which the upper petals of a coherent corolla are so 

 curved inwards that they close the entrance of the tube (as in 

 Antirrhinum) : the incurved portion is termed the palate (palatum)\ 

 the true bilabiate or mouth-like corolla (corolla ringens), in the 

 Labiates, in which the two petals forming the upper lip often 

 present a concave form overhanging the lower lip, termed galea ; 

 the so-called papilionaceous flowers of the Leguminosce, in which 

 the uppermost leaf, which is broad and large, surpassing the others, 

 is termed the standard (vexillum), whilst the lateral petals, as wings 

 (alee), are usually dissimilarly developed, and the two undermost, 

 very frequently coherent, also developed unequally at the two 

 sides, approach each other in a concave form, so as to form the 

 keel (carina). Sometimes all the petals of the papilionaceous 

 flowers become coherent at the lower part, and form a tube, as in 

 Trifolium; or individual petals are abortive, &c. The most irre- 

 gular of all the forms have hitherto received no names ; such as 

 appear, for instance, in the Potygalaceae, the Balsaminacece, Tro- 

 pceolacece, &c. 



All that has been said respecting the structure of the perianth 

 holds good of the structure of the corolla, except that this is 

 more delicate. The contents of the cells vary very much in colouring 

 matter, and their distribution in groups is sometimes very remark- 

 able. Very dense texture, in consequence of the presence of much- 

 thickened porous cells, as in the Amarantacea, is infrequent. 



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