82 



FLOWERS. 



[SECTION s. 



225 



calyx and corolla. Such are completely furnished with all that belongs to 



a flower. 



Regular, when all the parts of each set are alike in shape and size. 

 Symmetrical, when there is au equal number of parts in each set or circle 



of organs. 



240. Flax-flowers were taken for a pattern in Section II. 16. But in 



them the live pistils have their ovaries as it were consolidated into one body. 

 Sedum, Pig. 222, has the pistils and all the other parts 

 free from such combination. The flower is perfect, 

 complete, regular, and symmetrical, but is not quite 

 as simple as it might be ; for there are twice as many 

 stamens as there are of the other organs. Crassula, 

 a relative of Sedum, cultivated in the conservatories 

 for winter blossoming (Fig. 224) is simpler, being 

 isostemonous, or with just as many stamens as petals or 

 sepals, while Sedum is diplostemonous, having double 

 that number : it has, indeed, two sets of stamens. 



241. Numerical Plan. A certain number either 

 runs through the flower or is discernible in some of 

 its parts. This number is most commonly either five 

 or three, not very rarely four, occasionally two. Thus 

 the ground-plan of the flowers thus far used for illus- 

 tration is five. That of Trillium (Fig. 226, 227) is 



three, as it likewise is as really, if not as plainly, in Tulips and Lilies, Crocus, 



Iris, and all that class of blossoms. In some Scdums all the flowers are 



in fours. In others the first flowers are 



on the plan of five, the rest mostly on 



the plan of four, that is, with four sepals, 



four petals, eight 



stamens (i. e. twice 



four), and four pis- 

 tils. Whatever the 



ground number may 



be, it runs through 



the whole in symmet- 

 rical blossoms. 227 226 



242. Alternation of the successive Circles. In these flowers the 



parts of the successive circles alternate, ; and such is the rule. That is, 



Fio. 224. Flower of a Crassnla. 225. Diagram or ground-plan of same. 



Fio. 226. Flower of a Trillium; its juris in threes. 



Fio. 227. Diagram of flower of Trillium. In tliis, as in all such diagrams of cross- 

 section of Mossoms, the jwts of the outer circle represent the calyx ; the next, co- 

 rolla; witliin. stamens (here in two circles of three each, and the cross-section is 

 through the anthers) ; in the centre, section of three ovaries joined into a compound 

 one of three cells 



