tussock

A tussock is a tuft or clump of vegetation, typically grasses, that grows as a compact, upright tuft of leaves. Tussocks are produced when perennial grasses or other herbaceous plants spread slowly by tillers or short rhizomes and form a dense crown that stands above the surrounding vegetation. This growth habit often yields a raised, mound-like clump with a relatively bare center in older tussocks.

In natural ecosystems, tussocks shape microhabitats and influence soil moisture and nutrient cycling. They can protect soils from erosion, trap organic matter, and create sheltered microenvironments for invertebrates and small plants. Tussock vegetation is characteristic of certain cold or high-altitude environments, notably tussock tundra and tussock grasslands. In Arctic and subarctic regions, grasses and sedges such as Eriophorum and Carex form dense tussocks. In temperate regions like New Zealand and parts of the Southern Hemisphere, dominant tussock grasses include species in the genera Chionochloa, Festuca, and Poa, which create extensive grassland landscapes.

Humans use tussock-forming grasses in horticulture and land restoration. Ornamental tussocks are valued for their architectural form in gardens, while in restoration and erosion control projects, tussock grasses help stabilize soils and reestablish native vegetation.

Overall, tussocks describe a growth form rather than a single species, reflecting how clonal expansion and crown development can create distinctive, mound-like clumps across various environments.