Grasses

Along with true grasses (Poaceae), several other families of grass-like plants are typically marketed as Ornamental Grasses. These include the sedges (Cyperaceae), rushes (Juncaceae), restios (Restionaceae), and cat-tails (Typhaceae). All are monocotyledons, typically with narrow leaves and parallel veins, although there are some such as Acorus (Araceae or Arum family) and Ophiopogon (Liliaceae, or the lily family) .

Most Ornamental Grasses are deciduous herbaceous perennials, though many are evergreen and some develop woody tissues. They bring striking linear form, texture, colour, motion and sound to the garden throughout the year. Almost all ornamental grasses are perennials, coming up in spring, from their roots,which have stored large quantities of energy, and in fall or winter go dormant. Some, notably bamboos, are evergreen, and a few are annuals. Many are bunchgrasses and tussock grasses, though others form extensive systems of many-branched rhizomes. The bunching types are often called"clump-forming" or "clumping," distinct from therhizomatous types, called "running". Sizes vary from a few centimetres up to several metres; the larger bamboos may reach 20 m or more tall.