Ruohonlehti

Ruohonlehti, Finnish for grass leaf, is the photosynthetic leaf of a grass plant (family Poaceae). Typical grass leaves consist of a basal sheath that encloses the culm and a flat blade that extends from the sheath, connected at a joint called the ligule; in many species the blade may have small appendages called auricles at the base.

Anatomy and growth: Grasses have parallel leaf venation with many narrow veins running lengthwise. The epidermis bears stomata, usually on both surfaces but more densely on the lower surface. In many C4 grasses, the internal leaf anatomy places photosynthetic activity in bundle sheath cells around vascular bundles (Kranz anatomy). Leaves grow from intercalary meristems at the base of the blade and sheath, a feature that permits rapid elongation and quick regrowth after grazing or mowing.

Function and ecology: The leaf is the primary site of photosynthesis and gas exchange, contributing to transpiration and energy capture for the plant. Leaves vary in size and shape across species, from slender blades to broad blades, and they form the green canopy of lawns, meadows, and crops.

Human uses: Grass leaves underpin turfgrass lawns, pastures, and forage crops; some grasses are cultivated for seed production or ornamental use. Leaves can also accumulate silica in epidermal cells, contributing to toughness in some species.