| 240 “s tructural ae Plsiological Botany, ef 
a The best 1S the Sexual Bhar of Linneus: “which bases its principle 
orders with respect to the pistils. His orders are divided into genera, 
of classification on the essential parts of the flower, the stamens and 
pistils (or as we should now say, carpels). Lae a a “ 2 
THE LINNEAN SYSTEM. 
Linnzeus divided the vegetable kingdom into 24 classes, dependent © 
on the number and arrangement of the stamens ; and these, again, into 
and these into species. | 
The first 23 classes comprise Flowering Plants, those which possess 
stamens and pistils (or in a few cases ovules only in place of the pistil). | 
Of these classes, I.—X X. comprise plants with hermaphrodite flowers, 
_z.e. those in which the stamens and pistils occur in the same flower. 
Classes XXI., XXII., and XXIII. include plants with imperfect uni- 
sexual flowers, containing stamens only (staminate or male flowers, 3) ; 
or pistils only (pistillate or female flowers, 9). In the first 11 classes, 
the number of free stamens forms the basis of classification ; the length 
of the stamens is immaterial, with the exception of the 4th and 6th 
classes, in which they must be all of equal length. In the 12th and 
- 13th classes, the number and mode of attachment of the free stamens 
is taken into account ; and in the 14th and 15th the number and un- 
equal length of the free stamens. In the 16th, 17th, 18th, and 19th 
classes, Linnzeus included those plants in which the stamens are co- 
herent to one another; in the 20th, those in which the stamens are 
adherent to the pistil. Their characters, therefore, are as follows : 
Class I. MONANDRIA. I free stamen in a hermaphrodite flowers of 
(Fig. 211 B, p. 116). 
Class II. DIANDRIA. 2 free stamens ina hermaphrodite cage 
Class III. TRIANDRIA. 3 free stamens in a hermaphrodite flower 
(Fig. 264, p. 136). 
Class IV. TETRANDRIA. 4 free stamens of equal length in a her- | 
| maphrodite flower. Re 
Class V. PENTANDRIA. 5 free stamens in a hermaphrodite flower 
(Fig, 265, p. 136). . 
Class VI. HEXANDRIA. 6 free stamens of equal length in a her- 
maphrodite flower. 
‘Class VII. HEPTANDRIA. 7 free stamens in a hermaphrodite . 
flower. eed as 
Class VIII. OcCTANDRIA. 8 free stamens in a hermaphrodite 
flower. Ae 
