The stately and beautiful genus of goldenrods begins to bloom at midsummer, or earlier in the ease of the early goldenrod, and in November there are still visible the flower clusters of the Canada goldenrod and the tall hairy goldenrod, while the salt-marsh goldenrod may prolong the season until December. There are about 85 described species, confined chiefly to North America, with a few in South America and Europe. Fifty species occur north of Tennessee and east of the Rocky Mountains. They are closely allied, often hybridize, and are difficult to distinguish. There is a form adapted to almost every kind of location. The woodland goldenrod (S. caesia) is found in open woodlands; the field goldenrod (S. nemoralis) is very common in dry fields; the rock goldenrod (S. rupestris) prefers rocky situations; the swamp goldenrod (S. neglecta) lives in swamps; while the seaside goldenrod (S. sempervirens) thrives in salt marshes. (Fig. 61.)
Although the individual heads are so small, conspicuousness is gained by massing them in great plumelike clusters or panicles. Their bright yellow color renders them visible both by day and evening; and, as the temperature at night is several degrees above the surrounding air, they sometimes serve as a temporary refuge for insects. The floral tube is very short, seldom over one millimeter in length, so that there are few insects which are unable to gather the nectar. In Wisconsin Graenicher has taken on the early goldenrod (S. juncea) 182 different species of bees, wasps, flies, butterflies, and beetles either sucking nectar, or collecting or feeding on pollen; and on the Canada goldenrod (S. canadensis) 144 visitors. The honeybee visits the florets so rapidly that the number of visits per minute can not be counted. A large amount of pollen is gathered both by the domestic bee and by wild bees. So abundant, indeed, are the flowers, and so ample the stores of pollen and nectar, that four or five of our native wild bees, which fly only in autumn, never visit any other plants. Some of the goldenrods are pleasantly scented, others are odorless.
GOOSEBERRY. — See Currant.
GORSE. — See Furze under Pollen Plants.
GRANJENO. — See Hackberry.
GRAPE (Vitis). — It has been claimed that the grape is wind-pollinated, and occasionally the pollen is carried by the wind; but the whole structure of the flower is adapted to insect pollination. The small greenish yellow flowers depend on their delightful odor to attract insects. The fragrance resembles that of mignonette and can be perceived for a long distance. Kerner relates that in a journey up the Danube, in the valley called the Wachan, the air was so filled with the scent of the flowers that it seemed impossible that they could be far off, and yet the nearest vines were 900 feet away from the boat. There are five nectaries, which in central Europe are functionless and secrete no nectar; but in warmer regions Delpino states that nectar is secreted freely. At Dulac, La., a good flow from wild vines is reported, and Vitis californica in the Coast Ranges of California is said to yield nectar; but these observations should be confirmed. There is only a small amount of pollen. The flowers are visited by honeybees, bumblebees, and smaller bees. Beetles are common on the flower-clusters and sometimes do great injury. The vines remain in bloom for about ten days.
GREASEWOOD. — See Chamise.
GUM-PLANT (Grindelia squarrosa). — Many acres of the dry plains of Manitoba and Minnesota are covered by its yellow flowers, which honeybees visit in great numbers. A coarse herb, blooming from July to October.
HACKBERRY (Celtis). — Also called sugarberry and nettle-tree. The blackberries are shrubs, or small trees, on which the leaves and flowers appear at the same time. The small greenish flowers are borne in the axils of the leaves, and are partly staminate and partly pistillate. The species are more numerous in the South than in the North, and are valuable for both pollen and nectar. The common hackberry (C. occidentals) extends from Canada to western Texas, and in Illinois