Examine the flower. Its leaves cannot be distinguished into calyx and corolla, but are quite similar to each other in size, shape, and colour. They are therefore called the perianth. The perianth leaves are united to form a tube. Tear down the tube to see the six stamens fixed on it. Are they all on the same level? Examine the pistil and cut the ovary across to see the ovules in the three joined carpels. Which is fixed at the higher level, the perianth or the base of the pistil?
2. Other plants of the lily family.—Examine also the white lily, tulip, star of Bethlehem, and lily of the valley, and notice that in spite of small differences they are all monocotyledons (how do you know this?) and all have the perianth fixed below the ovary.
3. The snowdrop.—Compare and contrast the snowdrop ([Fig. 95]). Make out that it is a monocotyledon, but that its perianth is inserted above the ovary. This is the great point of difference from the lily family. Notice also how the stamens are fixed.
Fig. 94.—Wild Hyacinth. (× ¹⁄₁₀.) Fig. 95.—Snowdrops. (× ¼.)
4. Other plants of the snowdrop family.—Examine the daffodil (Figs. [ 55] and [ 96]) and narcissus. Arising from the short perianth tube of the daffodil is a longer one which is often mistaken for a corolla; it is called the corona. None of the flowers hitherto described contains anything corresponding to a corona. The corona in the narcissus is short. As in the snowdrop, the perianth is fixed above the ovary. Observe how the stamens are fixed, and notice the dry leaf beneath the flower.
The lily family.—Either the wild hyacinth ([Fig. 94]) or the cultivated single hyacinth may be taken as a good representative of this family. The first point which strikes the student on examining the general “habit” of the plant is the character of the long sheathing leaves. Their veins do not form an obvious network, such as is seen in the leaves of dicotyledons, but run lengthwise and roughly parallel to each other in the manner characteristic of grasses and other monocotyledons ([p. 40]). The leaves are narrow, and are not divided into blade and stalk; they and the flower stalk spring from an underground bulb ([p. 84]) which consists chiefly of the swollen leaf-bases of a previous season. A separate calyx and corolla are not to be distinguished in the flower; the six leaves being all alike in size, shape, and colour. These six leaves hence receive a special name, and are called the perianth. The perianth leaves are united into a tube, on the inside of which the six stamens are arranged in two series of three each. In the middle of the flower, and fixed above the insertion of the perianth, is the pistil, which consists of three united carpels.
