Grasses  belong to the Poaceae plant family previously known as Gramineae. Most grasses are herbaceous (non-woody) monocotyledonous plants with one leaf emerging from the seed, and they have jointed, slender, sheathed leaves.

Annuals complete their life cycle in one year. There are summer and winter annuals, indicating their time of planting (spring and fall, respectively).

Biennials live more than one year, indicating that they will overwinter if sufficiently winter-hardy, continuing to grow the following spring and summer.

Perennials have a multi-year life cycle ranging from short (2-3 years) to long-lived species (as much as decades).

Cool-season species have an optimal temperature range of 18-22 C (  F). Thus, greatest forage production occurs in the spring and fall.  Winter-hardiness ranges from tolerant of mild to severe cold. These species have a C-3 physiology and anatomy, characterized by carbon fixation via ribulose bis-phosphate carboxylase (RUBPcase) and highly digestible leaves with several layers of mesophyll cells and few bundle sheath cells.

Warm-season species have an optimal temperature range of  28-32 C ( F). Greatest forage production occurs during the summer. Typically, they are not cold-tolerant, requiring 55-60 F soil temperature for high germination and hard frost (26 F) finishes their seasonal growth. These species have a C-4 physiology and anatomy, characterized by carbon fixation by two enzymes; RUBPcase (as with C-3 species) and phosphoenol pyruvate carboxylase (PEPcase), few mesophyll cells, and many bundle sheath cells resulting in lower digestibility.

Grasses

Common Namesort descending Latin Name
Barley x Elyhordeum Barley Mansf. ex Zizin & Petrowa
Bermudagrass Cynodon dactylon (L.) Pers.
Corn Zea mays L.
Crabgrass Digitaria Haller
Foxtail Millet Setaria italica (L.) P. Beauv.
Oat Avena sativa L.
Orchardgrass Dactylis glomerata L.
Pearlmillet Pennisetum glaucum (L.) R. Br.
Perennial Ryegrass Lolium perenne L.
Rye Secale cereale L.
Soft Brome Bromus hordeaceus L.
Sorghum Sorghum bicolor (L.) Moench
Tall Fescue Schedonorus arundinaceus
Teff Eragrostis tef (Zuccagni) Trotter
Triticale x Tritocosecale Wittm. ex. A. Camus
Wheat Triticum aestivum L.