Fig. 79.—Poison Hemlock. (× ¼.) Fig. 80.—Hedge Parsley. (× ⅙.)
The parsley family.—The plants of this family may be recognised easily by the arrangement of the flowers. Several stalks spring together from the top of the main flower stalk and each of these again gives rise at its tip to a number of smaller stalks, at the ends of which the small flowers are borne ([Figs. 79 and 80]). The flowers are fertilised by the aid of insects, and as the nectar is on the surface it is accessible to small insects such as flies, beetles, etc. The flowers are rendered more conspicuous by being placed close together. The stems are usually hollow, and the leaves are alternate, and generally compound, with sheathing bases. Many of the plants of this family are very poisonous, and such should be carefully distinguished and whenever possible exterminated.
The poison hemlock ([Fig. 79]) varies in height from two to seven feet. It has a hollow stem which is spotted with purple in the lower part, and when bruised the leaves give off a smell like that of mice. Cattle are often poisoned by eating the plant in hay, and children have been poisoned even by blowing whistles made from the stem. The water-hemlock is extremely poisonous. It grows along the sides of pools. The stem is hollow, and the leaflets of the compound leaves are finely toothed. The root is a cluster of fleshy swellings, and has unfortunately a rather pleasant taste. Other poisonous plants of the family are the water dropwort and the fool’s-parsley. Among the harmless and useful members of the group are celery (when cultivated), carrot, parsnip, and parsley.
21. THE PRIMROSE AND COWSLIP.
1. The primrose.—Examine the habit ([Fig. 81]) of the plant, its underground stem, its spoon-shaped leaves—arranged in a rosette—and the manner in which the flowers spring from the stem. In the flower make out (a) the calyx, 5-pointed and with united sepals; (b) the corolla, consisting of 5 petals united below into a tube. Tear down the corolla-tube to see (c) the 5 stamens inserted on the corolla-tube. In some (“thrum-eyed”) flowers the anthers are at the top of the tube; in others (“pin-eyed”), they are halfway down; (d) the pistil, consisting of stigma, style, and ovary. In thrum-eyed flowers the style is short and the stigma is halfway down the corolla-tube; while in pin-eyed flowers the style is long and the stigma is at the top of the tube. Do you find both pin-eyed and thrum-eyed flowers on the same plant, or does one plant bear only one kind?
2. Fertilisation.—Cover up a plant of each kind with gauze, to keep insects from the flowers, and notice whether the covered flowers ripen seeds like the others.
3. The cowslip.—Compare the cowslip ([Fig. 83]), and notice that the main stalk gives off from the same point several smaller stalks, each of which bears a flower. Observe that the cowslip also has both pin-eyed and thrum-eyed forms of flowers.
Fig. 81.—Primrose. (× ¼.)