Graminoid

This article is about plants with a grass-like appearance. For the clade containing Poaceae and some related families, see Graminid clade.

In botany and ecology, a graminoid refers to a herbaceous plant with a grass-like morphology,^[1] i.e., elongated culms with long, blade-like leaves. They are contrasted with forbs, herbaceous plants without grass-like features.

Germinating fescue grass with long, blade-like leaves

The plants most often referred to include the families Poaceae (grasses in the strict sense), Cyperaceae (sedges), and Juncaceae (rushes). These are not closely related but belong to different clades in the order Poales. The grasses (Poaceae) are by far the largest family, with some 12,000 species.

Common traits

A graminoid is a plant that has a simple structure of repeated parts that have their meristems, growing parts, within their stems. They frequently have well developed ways of reproducing vegetatively, without needing to grow from pollinated seeds. As a group the graminoids produce fewer toxins than other plants and instead rely on physical defenses against being eaten by herbivores. Their evolution has been in response to grazing by both mammals and insects.^[2]

Ecology

Besides their similar morphology, graminoids share a widespread occurrence and often dominance in open habitats such as grasslands or marshes. They can, however, also be found in the understory of forests. Sedges and rushes tend to prefer wetter habitats than grasses.

Gallery

• Examples of graminoid plants
•  
  Common rush (Juncus effusus), Juncaceae
•  
  Nutsedge (Cyperus capitatus), Cyperaceae
•  
  Festuca cinerea, Poaceae

Etymology

 

Look up graminoid in Wiktionary, the free dictionary.

The word graminoid is derived from Latin grāmen 'grass; herb', with the suffix -oid denoting '-like; resembling, characteristic of'.^[3] The Latin grāmen may be related to the English grass through a common word in the Proto-Indo-European language. However, grass is a Germanic word comparable to the Old Frisian gres or Old High German gras. In Old English it was gærsum which changed over time into the modern word. It was first spelled grass in 1393, but continued to be spelled variously through at least 1637.^[4]

See also

• Reed
• Seagrass

References

1. Park, Chris; Allaby, Michael (2017). A Dictionary of Environment and Conservation. Oxford University Press. doi:10.1093/acref/9780191826320.001.0001. ISBN 9780191826320.
2. Jefferies 1988, p. 342.
3. Grove 1981, p. 986. sfn error: no target: CITEREFGrove1981 (help)
4. OED 2025.

Sources

Books

• Gove, Philip Babcock, ed. (1981). Webster's Third New International Dictionary of the English language, Unabridged. Vol. I: A to G. Springfield, Massachusetts: G. & C. Merriam Co. ISBN 978-0-87779-201-7. OCLC 8838804. Retrieved 3 July 2025.
• Jefferies, R.L. (1988). "13 : Vegetational mosaics, plant-animal interactions and resources for plant growth". In Gottlieb, Leslie D.; Jain, Subodh K. (eds.). Plant Evolutionary Biology (First ed.). London ; New York: Chapman and Hall. ISBN 978-0-412-29290-3. OCLC 17233777. Retrieved 3 July 2025.

Web sources

• "grass (n.1)". Oxford English Dictionary (Online ed.). Oxford University Press. doi:10.1093/OED/6956138275. (Subscription or participating institution membership required.)