13. The characters of the ORDERS are most commonly taken from the number of the pistils; but sometimes from circumstances relative to the stamens, pistils, or seed. Those of the first thirteen classes are taken from the number of pistils, thus:
| Monogynia | 1 | pistil. | Heptagynia | 7 | pistils. |
| Digynia | 2 | pistils. | Octagynia | 8 | pistils. |
| Trigynia | 3 | pistils. | Enneagynia | 9 | pistils. |
| Tetragynia | 4 | pistils. | Decagynia | 10 | pistils. |
| Pentagynia | 5 | pistils. | Dodecagynia | about 12 | pistils. |
| Hexagynia | 6 | pistils. | Polygynia | many | pistils. |
The orders of the fourteenth class, Didynamia, are taken from the situation of the seeds; and are
| Gymnospermia | naked seeds. |
| Angiospermia | seeds in a capsule. |
The orders of the fifteenth class, Tetradynamia, are formed from a difference in the shape of the seed-vessel:
| Siliculosa | a broad pod. |
| Siliquosa | a long pod. |
In the classes Monadelphia, Diadelphia, Polyadelphia, and Gynandria, the orders are taken from the number of stamens:
| Pentandria | 5 stamens. |
| Hexandria, &c. | 6 stamens, &c. |
In the nineteenth class, Syngenesia, the orders are taken from the structure of the flower:
Polygamia æqualis,—all the florets alike.