2, longitudinal section of flower; 3, longitudinal section of fruit. The differences between the rose, blackberry, raspberry, and strawberry are more marked when the pistil has become a fruit. The fleshy part of the rose hip is the urn-shaped receptacle which encloses the ripened carpels. In the case of the blackberry and raspberry the receptacle is dry, and is surrounded by the compound fruit (Fig. 76, 3) of the several bodies like little plums or cherries. The eatable part of the strawberry fruit (Fig. 144) is the swollen receptacle, on the outside [Pg 106] of which are the little yellow nutlets derived from the carpels of the flower. In the cherry (Fig. 77), plum, and apricot the pistil consists of only one carpel, which is enclosed in the urn-like receptacle. After fertilisation, the greater part of the wall of the ovary becomes fleshy, and one of the two ovules contained in it becomes a seed. The “stone” is formed from the innermost part of the ovary wall. The apple (Fig. 74) and pear (Fig. 78) have their five carpels embedded in the receptacle, and the rest of the flower stands on this part. The eatable portion of the fruit is the swollen receptacle. The hawthorn has usually only two carpels, and in the fruit the part derived from the receptacle becomes hard and horny. In other respects it is very similar to the apple. Fig. 78.—Pear. 1, flowering branch (× ⅔); 2, longitudinal section of flower; 3, longitudinal section of fruit; 4, diagram of flower. The rose family is widely distributed, especially in temperate regions. 20. THE PARSLEY FAMILY. 1. The poison hemlock.—Examine this plant (Fig. 79) very carefully, remembering that it is poisonous. Notice the general habit of growth; the characters of the sheathing, compound leaves; the hollow ribbed stem; and also the arrangement of the flowers, which is characteristic of the family. From the top of a main flower-stalk [Pg 107] several smaller stalks come off together, like the ribs of an umbrella. From the top of each of these spring the stalklets which bear the small white flowers. Notice the bracts at the points of origin of the stalks. Examine the flowers, and watch insects visiting them. Which insects are most commonly found on the flowers? Compare the cow parsnip, the water hemlock, carrot, parsley, parsnip, and celery, carefully noting the points of resemblance and difference. Fig. 79.—Poison Hemlock. (× ¼.) Fig. 80.—Hedge Parsley. (× ⅙.)