9. Rushes and sedges.—Rushes and sedges are sometimes mistaken for grasses. Examine the stems, the flowers, and the leaves (look for ligules), and tabulate as many differences from the true grasses as possible.
The student should learn to recognise the common grasses and to distinguish the useful species from the weeds. When the grasses are in flower there is not much difficulty in doing this, but the habit of growth—the characters of the leaves and roots, and of the stolons of the perennial species—should also be noticed carefully, as during the greater part of the year these alone can be depended upon.
Fig. 104.—Meadow Foxtail. (× ⅙.) Fig. 105.—Slender Foxtail. (× ⅙.)
The fescues fall into two groups according as their leaves are broad or narrow. The meadow fescue is a good example of the former group. It is found in meadows and pastures and has long broad leaves. Sheep’s fescue ([Fig. 102]) is a good example of the second group of fescues. It has very fine—almost bristle-shaped—leaves. Like the meadow fescue it grows in tufts; it inhabits high lands and downs, especially in limestone districts. The nodding spikelets are borne on fairly long stalks, and the panicles are somewhat like those of the meadow grasses ([Fig. 103]). The flowers of sheep’s fescue, however, bear short awns.
The meadow grasses much resemble the fescues in general appearance, but the panicles ([Fig. 103]) are rather more tree-like—the stalks of the spikelets spreading more horizontally—and the flowers are never awned. The various species can be distinguished by their ligules; for example, the ligule of the smooth-stalked meadow grass ([Fig. 103]) is blunt, while that of the rough-stalked species is long and pointed. The annual meadow grass is a weed to be found almost everywhere.
Fig. 106.—Timothy Grass. (× ⅙.)