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 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.
