188 



HOW TO STUDY PLANTS. 



[LESSON 31. 



centre of the flower is of the ordinary sort, enclosing the ovules : so 

 the plant belongs to Subclass I. ANGIOSPERM^E. 



544. To get a good idea of the general plan of the flower, let the 

 student cut it through the middle lengthwise, as in Fig. 364, and 



364 



also take a slice across a flower-bud, like Fig. 365. We see that 

 the blossom is regularly constructed upon the number five. It has 

 a calyx of five sepals, a corolla of five petals, five stamens, and five 

 styles, with their ovaries all combined into one compound ovary. 



We note, also, that the several parts of the blos- 

 som are all free and unconnected, the leaves 

 of the calyx, the petals, and the stamens all ris- 

 ing separately one after another from the re- 

 ceptacle underneath the ovary: that is, these 

 parts are hypogynous (269). 



545. Continuing now our analysis by means 

 of the Artificial Key, we perceive at a glance that our plant belongs 

 to the first or POLYPETALOUS division, having five separate petals. 

 Next, its stamens, being only five, exclude it from the subdi- 

 vision marked A ; their position alternate with the petals excludes 

 it from B (p. xviii), but brings it under C. Under this comes the 

 alternative between " 1. Calyx free from the ovary'' and its coun- 

 terpart, 2. (at the top of p. xx), in which the tube of the calyx is 

 adherent to the ovary. The first is the case here. 



546. Under the next alternative ( * ) we are led to ask whether 

 the leaves are punctate with dots, either transparent, appearing 

 like holes when we hold up a leaf between the eye and the light 



FIG. 3G3. Summit of a branch of the common Flax, with two flowers. 364. A flower 

 divided lengthwise and enlarged. 

 FIG. 365. Cross-section of an unexpanded flower of the same, a sort of diagram. 



