Grass Family

Purple Needle Grass © TCorelli

Poaceae (poh-AY-see-ee)

Iconic Features

    • Hollow stems
    • Usually narrow, sheathing leaves
    • Small, petalless, pale flowers
    • Fruit a grain

    Description (Jepson)

      • Annuals or herbaceous perennials
      • Monocotyledons (monocots) – monocots are a major lineage of flowering, mostly herbaceous plants, generally characterized by
        • Single seed leaf (cotyledon)
        • Linear or oblong leaves with parallel venation
        • Flower parts in threes
        • Pollen grains with a single pore
        • Vascular bundles scattered in stem
        • Fibrous root system
      • Leaves
        • Usually narrow leaves sheathing the stem
        • Sheaths usually with a small appendage called a ligule
        • Alternate (1 leaf at each junction with stem)
      • Flowers
        • Small, generally bisexual, petalless flowers in spikelets
        • Wind pollinated
      • Fruit a grain (a dry, one-seeded fruit with a fused seed coat)
      Grass Family Characteristics © LAbrams and RFerris

      Notes

        • Approximately 10,550 species worldwide
          • Includes wild and cultivated species of wheat, rice, corn, rye, fescue, brome, oats, barley, and bamboo
          • Greatest economic importance of any plant family
        • Grasses, oaks, and silk tassels are examples of plants at Edgewood that are wind pollinated
          • About 12% of flowering plants and most conifers are wind-pollinated (US Forest Service)
          • These plants do not waste energy on flower features that attract animal pollinators; instead, their flowers generally have these characteristics
            • Minute, inconspicuous, petalless flowers
            • No nectar
            • Stamen (male flower part) and stigma (pollen receiving structure of female flower part) are exposed to air currents
            • Male flowers produce a great deal of pollen, which is very small, dry, and easily airborne, as all allergy sufferers know!
        • Scientific name from the included genus Poa, from the Greek for “fodder”
        • Represented by 56 species at Edgewood

        See General References

        Specific References

          Abrams, L.R. and Ferris, R.S. 1940-1960. Illustrations. Illustrated Flora of the Pacific States, Washington, Oregon and California (IFPS). Four volumes. Stanford University Press, Stanford, California. Public Domain.

            US Forest Service. Celebrating Flowers: Wind and Water Pollination. United States Department of Agriculture.

            Browse Some Edgewood Plants in this Family