Goldenrod

Goldenrod — The goldenrod is a yellow flowering plant in the Family Asteraceae.

About 100 perennial species make up the genus Solidago, most being found in the meadows and pastures, along roads, ditches and waste areas in North America. There are a handful of species from each of Mexico, South America, and Eurasia. Some American species have also been introduced into Europe some 250 years ago.

Many species are difficult to distinguish. Probably due to their bright, golden yellow flower heads blooming in late summer, the goldenrod is often unfairly blamed for causing hay fever in humans. The pollen causing these allergy problems is mainly produced by Ragweed (Ambrosia sp.), blooming at the same time as the goldenrod, but is wind-pollinated. Goldenrod pollen is too heavy and sticky to be blown far from the flowers, and is thus mainly pollinated by insects.

Goldenrods are easily recognized by their golden inflorescence with hundreds of small capitula, but some are spike-like and other have auxiliary racemes.

They have slender stems, usually hairless but S. canadensis shows hairs on the upper stem. They can grow to a length between 60 cm and 1.5 m.

Their alternate leaves are linear to lanceolate. Their margins are usually finely to sharply serrated.

Propagation is by wind-disseminated seed or by underground rhizomes. They form patches that are actually vegetative clones of a single plant.