lehepistikud

Lehepistikud, scientifically known as Equisetum, are a genus of vascular plants in the division Equisetophyta. They are commonly referred to as horsetails or scouring rushes. These plants are ancient, with fossil evidence suggesting they were widespread and dominant in the Carboniferous period. Today, lehepistikud are found in damp, often shaded environments across the globe, typically in temperate and arctic regions.

The most distinctive feature of lehepistikud is their unique morphology. They possess jointed, hollow stems that are often ribbed. The leaves are reduced to small, scale-like structures arranged in whorls at the nodes, and they are not the primary photosynthetic organs; the stems typically perform this function. Reproduction occurs via spores produced in cone-like structures called strobili, usually found at the tips of fertile stems.

Lehepistikud exhibit two distinct types of shoots: vegetative and reproductive. Vegetative shoots are typically green and perennial, responsible for photosynthesis and growth. Reproductive shoots are often non-photosynthetic, appearing earlier in the season, and bear the sporangia. Some species can reproduce vegetatively through underground rhizomes, allowing them to spread effectively.

Historically, the abrasive silica content in the stems of some lehepistikud species made them useful for scouring and polishing, hence the common name "scouring rush." Certain species have also been used in traditional medicine for their diuretic or wound-healing properties, though scientific evidence for these uses varies.