What Is a Ligule? The Small Collar Where a Grass Leaf Meets the Stem
A ligule is a thin membrane or a row of hairs where a grass leaf blade meets its sheath. University of Illinois Extension calls it an excellent clue for telling grasses apart.
The short answer
The ligule sits on the inside of the leaf at the junction of sheath and blade. Montana State University Extension says it is either membranous or hairy. Some grasses have none, and Illinois says its presence and its type help identify a grass. Pull the blade gently away from the stem to see it.
What is a ligule?
It is a small collar flap. Illinois says grass leaves have a blade and a sheath that wraps the stem. The collar is where the blade becomes the sheath. The ligule sits there with auricles and horns. Leaf structure is covered in cannabis leaf anatomy.
What types of ligules are there?
Three forms. The Florida circular lists a membranous flange, a row of hairs or a slight ridge. Illinois adds detail on each.
| Type | Detail | Source |
|---|---|---|
| Hairy | Short, stiff and numerous or long and sparse | Illinois |
| Membranous | Short or rather tall | Illinois |
| Absent | As in barnyard grass | Montana State |
Illinois says ligules are typically white on young grass and turn orange, yellow or brown later.
How does the ligule help identify grasses?
Size and form narrow it. Montana notes green needlegrass has a very short ligule. Needle and thread grass has a ligule 2 to 4 mm long. The Florida circular gives cogongrass a membrane 0.2 to 3.5 mm long. Water movement in plants is covered in cannabis xylem and phloem.
How to: step by step
- Pick a fresh grass stem with leaves.
- Find where the blade leaves the stem.
- Pull the blade gently away from the stem.
- Look at the inside of the collar with a hand lens.
- Note if the ligule is a membrane or hairs.
- Write down the plant name and date.
Troubleshooting
Cannot find the ligule: bend the blade back.
Hairs only: that is a hairy ligule. Look closely with a lens.
Nothing there: Montana says some grasses lack a ligule.
Kind Seed Co shares these plant notes for growers of all kinds. Seed parts are covered in cannabis seed anatomy and planting plans in planning an outdoor cannabis garden layout.
Sources
- Grass identification, University of Illinois Extension
- Grass identification basics (MT201402AG), Montana State University Extension
- Identifying grasses, Florida Department of Agriculture and Consumer Services
FAQ
Do all grasses have a ligule?
No. Montana State says some grasses such as barnyard grass have no ligule. On others it is very short and hard to see.
Is the ligule part of the leaf?
Yes. Montana State places it on the inside of the leaf blade at the junction of the sheath and blade.
How big is a ligule?
It varies. Montana State says needle and thread grass has a ligule 2 to 4 mm long while green needlegrass has a very short one.
Does a ligule change color?
Yes. Illinois says ligules are typically white when the grass is young and turn orange, yellow or brown as the season goes on.
What is the collar on a grass leaf?
Illinois calls it the region where the leaf blade becomes the sheath. Ligules, auricles and horns are found there.
