Page:An introduction to physiological and systematical botany (1st edition).djvu/286

 256 enclosed in the calyx of the Primrose; and the limb, limbus, which is the horizontal spreading portion of the same flower. The analogous parts of a polypetalous Corolla, as in the Wall-flower or Stock, are named the claw, unguis, and the border, lamina.

The Corolla is infinitely diversified in form in different genera, which Tournerfort and Rivinus derived their methods of arrangement. It is called regular when its general figure is uniform, as in the Rose, the Pink, the Columbine, Aquilegia vulgaris, ''Engl. Bot. t. 297, and Gentiana Pneumonanthe, t. 20; irregular when otherwise, as the Violet, t. 619, 620, Dead-nettle, t. 768, and Lathyrus, t.'' 805 and 1108. An equal Corolla is not only regular, but all its division are of one size, like those of the Primrose, t. 5, Campanula, t. 12, or Saxifraga, t. 9; an unequal one is when some segments are alternately smaller than the others, as in Butomus, t. 651, or otherwise different, as in Aquilegia, t. 297. It is by no means always necessary, in defining characters of genera, to use these last terms, it being