woodland horsetail

Great Plains

Midwest

FACW - Facultative wetland

Northcentral & Northeast

FACW - Facultative wetland

Native

Common

Moist. Coniferous, deciduous, and mixed forests, thickets, meadows, bogs, swamps, and streambanks. Partial shade.

April through May

10″ to 27″

This is the only horsetail on which the branches are themselves branched.

Sources: 2, 3, 4, 5, 7, 28, 29.

Taxonomy
There are 15 species of Equisetum, which is the only living genus in the family Equisetaceae, which is the only family in the order Equisetales, which is the only order in the class Equisetopsida. The history of Equisetum has been traced 300 million years to the Cretaceous period, and possibly to the Triassic period. That could make Equisetum the oldest living genus of vascular plants.

The genus Equisetum is divided into two subgenera, Equisetum and Hippochaete. water horsetail is one of the eight species in the subgenus Equisetum. Six of those eight species are found in North America. Five are found in Minnesota.

In this subgenus, the stems tend to be regularly branched, the branches appearing in a whorl at each stem node. This gives the plant the appearance of a horse’s tail, giving rise to the common name “horsetail”. The aerial stems of most of the species in this subgenus are annual.

Subspecies
This pant is highly variable. Some sources describe three subspecies based on the amount of branching and the texture of the branches. Most sources do not recognize any subspecies.

Plant

Cones

Cone

Branches

Sheath

Teeth

Plant

Sheath