Logo317id.GIF (10125 bytes)

Grass Weed Identification ToolKit

Grass weed morphology and ID is often much harder than broadleaf weed ID. This is because superficially all grasses look the same. Get close, and you will notice many features that will guide your ID.


Leaf morphology

1101t.JPG (4913 bytes) This is a generic grass leaf in cross-section. Notice the prominent midrib.


Ligule & Collar region

The different parts of the collar region, where the leaf blade joins the culm (stem), can be a very revealing area for grass ID.

Below (clockwise): Upper right: blade; middle right: collar region; lower right: sheath; lower left: auricles; middle left: ligule

1026t.JPG (5028 bytes)

Below (Clockwise): lower right, sheath; lower left (2 arrows), auricles; collar; mid-left, ligule; leaf blade; upper left, midrib; upper right, leaf margin; mid-right, collar margin

1110t.JPG (6080 bytes)

Ligule types:

Membranous ligule 1023t.JPG (5766 bytes) 1029t.JPG (7009 bytes) 1100t.JPG (5436 bytes)
No ligule 1027t.JPG (6633 bytes) 1148t.JPG (4777 bytes)
Hairy ligule 1028t.JPG (7038 bytes) 1149t.JPG (5012 bytes)


Sheath:

No auricles: 1152t.JPG (5661 bytes) Auricles: 1153t.JPG (5852 bytes)
Sheath split with overlapping margins: 1154t.JPG (5436 bytes)
Sheath united: 1155t.JPG (5094 bytes)


Stems:

Round 1128t.JPG (6224 bytes) Oblong 1138t.JPG (7530 bytes)
Flat 1137t.JPG (4800 bytes) 1147t.JPG (6456 bytes)
Triangular (diagnostic for sedges) 1127t.JPG (6025 bytes)



Inflorescence, seedhead:

1018t.JPG (6662 bytes)

1021t.JPG (10955 bytes)


Seed:
(optional information; not required)

1244t.JPG (6520 bytes) From top: awn; lemmas; glumes
1245t.JPG (5623 bytes) From top: palea; lemma; rachilla
1246t.JPG (7460 bytes) From top: stamen; stigma; ovary; lodicule
1247t.JPG (6576 bytes) Top view: grass floral schematic diagram
1248t.JPG (7347 bytes) From top: hilum; endosperm; coleoptile; plumule; mesocotyl; epiblast; scutellum; scutellum cleft; coleorhiza

 

©jdekker-2003

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