Page:An introduction to physiological and systematical botany (1st edition).djvu/482

 452 does not so exactly agree with the above definition, having a flat disk; but its affinity to the other genera is indubitable. Its flattened disk and radiating coloured calyx seem contrived to imitate the radiated flowers of the following Order.

*** Flowers discoid, their florets all tubular, regular, crowded and parallel, forming a surface nearly flat, or exactly conical. Their colour is most generally yellow, in some cases pink. Santolina, t. 141; and Bidens, t. 1113, t. 1114, are genuine examples of this section: Eupatorium, t. 428, and the exotic Stæhelina, Dicks. Dr. Pl. 13, approach to the preceding one. There is however the most absolute difference between these two sections, collectively, and the first; while, on the other hand, they have considerable affinity with some of the following Orders, as will be hereafter explained.

2. Polygamia superflua. Florets of the disk perfect or united; those of the margin furnished with pistils only; but all producing perfect seed.