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AgSci» Crop and Soil Sciences» » for Turfgrass ScienceCenter » AdviceTurf » Factsheets Identificationseason Turfgrasses: -CoolThe
The Cool-season Turfgrasses: Identification
Turfgrass Identification
To develop successful lawn management programs and avoid problems, you must be able to identify turfgrass
species. Species react differently to management practices such as mowing, fertilization, and liming; thus, you
should know which grasses are present in the lawn so that you can adjust your management program accordingly.
Also, there are several pesticides that are safe to apply to some turfgrass species, but not others. If you apply a
herbicide that is safe only on Kentucky bluegrass to a fine fescue lawn, serious damage could result and you may
have to replace the lawn. Before making important lawn management decisions, make sure that you can identify the
turfgrass species present at the site.
Identification of the cool-season turfgrass species is not difficult once you learn how to recognize a few plant
structures and some subtle features associated with those structures. Descriptions of the plant parts used in
identification of turfgrasses are provided in the following paragraphs. Some of these have been discussed in “The
Cool Season Turfgrasses: Basic Structures, Growth and Development”. Diagrams and descriptions of identifying
features of cool-season turfgrass species are provided in this section.
Vernation
Vernation is a term used to describe how the youngest grass leaves are arranged in the shoot (inside of the leaf
sheath between the collar region and the crown). Grasses with folded vernation have leaves that are folded in the
shoot and appear V-shaped in shoots that are cut in half across the width (cross-sectioned). Leaves with rolled
vernation are circular or “rolled" in the shoot and do not have folds (Fig. 1). To determine if a grass specimen has
folded or rolled vernation, hold the shoot between your thumb and index finger and roll it. If it rolls like a straw, it
has rolled vernation, if it lies flat and has edges, it is folded. You can also determine vernation by cutting a cross-
section of the shoot just below the collar region and looking at the leaf arrangement.
Figure 1. Examples of folded and rolled vernation
CENTER FOR TURFGRASS SCIENCE
Page 1 of 9The Cool-season Turfgrasses: Identification — Center for Turfgrass Science
Leaf Blades
Leaf blades have certain characteristics that are useful in turfgrass identification. Some species have leaf blades with
a single prominent vein running lengthwise down the center of the blade. Others have many equal-sized veins (no
dominant mid-vein) running lengthwise over the entire width of the leaf blade (Fig. 2). A few species have both a
prominent mid-vein and many smaller veins oriented lengthwise over the entire width of the blade. Certain turfgrass
species have a glossy appearance on the underside of the leaf blade, whereas others are dull (not glossy). Some
turfgrasses have leaf blades that terminate in a flat point, whereas others have leaf blade tips that are keeled
(sometimes referred to as a ‘boat-shaped’ tip) (Fig. 2).
Figure 2. Leaf blade with prominent vein running lengthwise in center of blade (a) and one with many equal-sized
veins (no dominant mid-vein) running lenghtwise over the entire width of the blade (b). Diagram of turfgrass leaf
tips showing keeled, and flat and pointed.
Ligules and Auricles
Ligules are membranous or hairy tissues located at the junction of the leaf blade and leaf sheath. Depending on the
species, ligules can be membranous, a fringe of hairs, or absent (Fig. 3A). None of the cool-season turfgrasses have
ligules that appear as a fringe of hairs, but this feature is common on many weed grasses and most warm-season
turfgrasses. Auricles are slender extensions of the collar and are located at the junction of the leaf blade and leaf
sheath. They can be long and clasp around the stem or shoot, small or rudimentary, or absent (Fig. 3B).
Figure 3. In turfgrasses, ligules may be membranous, hairy, or entirely abscent. (B) Auricles may be long and
clasping, small or rudimentary, or abscent.
Page 2 of 9The Cool-season Turfgrasses: Identification — Center for Turfgrass Science
Growth Habit
Growth habits of cool-season turfgrasses are either rhizomatous (producing rhizomes), stoloniferous (producing
stolons), or bunch type (a species that does not produce rhizomes or stolons — only tillers). In some cases, the
growth habit of turfgrasses can be useful in identification. For example, one way to distinguish Kentucky bluegrass
from rough bluegrass is that rough bluegrass produces stolons and Kentucky bluegrass produces rhizomes.
Figure 4. Rhizomatous, bunch, and stoloniferous growth habits.
The Seed Head
Although seed head characteristics are among the best identifying features of turfgrass species, they are often
removed by mowing. Where seed heads can be observed, they are classified as panicle types, spike types, or
recemes. Recognizing difference among these seed head types can be useful in distinguishing among the cool-season
turfgrass species.
The Cool-season Turfgrasses: Identification — Center for Turfgrass Science Page 3 of 9
Figure 5. Three types of turfgrass seed head; panicle, spike and raceme.
Identifying Features of Cool-Season Turfgrass Species
Kentucky bluegrass
• Folded vernation
• Prominent mid-vein (no other veins noticeable), leaf blade dull underneath, keeled leaf tip
• Auricles absent
• Short, membranous ligule
• Rhizomatous growth habit
• Panicle-type seed head
Page 4 of 9The Cool-season Turfgrasses: Identification — Center for Turfgrass Science
Kentucky Bluegrass
Rough bluegrass
• Folded vernation
• Prominent mid-vein (no other veins noticeable), leaf blade glossy underneath, keeled leaf tip
• Auricles absent
• Short, membranous ligule
• Stoloniferous growth habit
• Panicle-type seed head
Rough Bluegrass
Perennial ryegrass
• Folded vernation
• Prominent mid-vein with many smaller veins oriented lengthwise over the entire width of leaf blade,
leaf blade glossy underneath, keeled leaf tip
• Small, rudimentary auricles
• Short, membranous ligule
• Bunch-type growth habit
• Spike-type seed head
Page 5 of 9The Cool-season Turfgrasses: Identification — Center for Turfgrass Science
Perennial Ryegrass
Annual ryegrass
• Rolled vernation
• Prominent mid-vein with many smaller veins oriented lengthwise over the entire width of leaf blade,
leaf blade glossy underneath, keeled leaf tip
• Long, clasping auricles
• Short, membranous ligule
• Bunch-type growth habit
• Spike-type seed head
Annual Ryegrass
Page 6 of 9The Cool-season Turfgrasses: Identification — Center for Turfgrass Science
Fine fescues
• Folded vernation
• Very narrow, folded leaf blades — in most cases veins not visible, leaf blade dull underneath, keeled
leaf tip
• Auricles absent
• Short, membranous ligule
• Bunch-type or rhizomatous growth habit
• Panicle-type seed head
Fine Fescues
Tall fescue
• Rolled vernation
• Blades have many equal-sized veins (no dominant mid vein) running lengthwise over the entire width
of the leaf blade, leaf blade dull underneath, pointed leaf tip
• Auricles absent
• Short, membranous ligule
• Primarily bunch-type growth habit, sometimes short rhizomes are present
• Panicle-type seed head
Page 7 of 9The Cool-season Turfgrasses: Identification — Center for Turfgrass Science
Tall Fescue
Creeping bentgrass
• Rolled vernation
• Blades have many equal-sized veins (no dominant mid vein) running lengthwise over the entire width
of the leaf blade, leaf blade dull underneath, pointed leaf tip.
• Auricles absent
• Tall, membranous ligule
• Stoloniferous growth habit
• Panicle-type seed head
Creeping Bentgrass
Prepared by Peter Landschoot, professor of turfgrass science
Page 8 of 9The Cool-season Turfgrasses: Identification — Center for Turfgrass Science