Family: horsetails (Equisetaceae)
Flowering time: April–May
Size: 50–150 cm
Habitat: moist soils by springs, in forests and on forest edges, low bogs
Great horsetail (Equisetum telmateia) is a tall plant that blooms between May and August. At that time it sends forth fertile shoots, which bear spores, as horsetails do not yet have developed true flowers with stamens or pistils, as we know from seeds. Its fertile shoots are brownish-whitish, usually between 10 and 25 cm tall and about 1 cm wide. Their leaves, grown into a serrated sheath that embraces the stem at the joints, are dark brown. When the fertile shoots die, from the subterranean rhizome sterile shoots sprout, whose task is to perform photosynthesis. The stem of the fertile shoots grows to 50–150 cm tall and has a diameter of 10–15 mm. It is not green, but whitish. The green ones are the lateral shoots, which are mistakenly called leaves.
Great horsetail preferably grows in partial shade; it does not tolerate direct sun very well. It thrives on soils moderately rich in nitrogen, moist soils on a base-rich substrate and is adapted to the reduced oxygen content in them. It is widespread throughout Slovenia.
