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Submerged Aquatic Identification Key

Leaf Arrangement

Read directions before getting started

Look at the way that the leaves are arranged on the stem of your sample. Look in several places to find the most common type of attachment. Don't look at the leaves where the stem divides into two, as this will often be different than the rest of the plant. Click on the selection that seems most appropriate.


image of basal leaf


image of whorl leaf


image of alternate leaf


image of opposite leaf
All leaves come from the base of the plant at the sediment surface. The leaves come from the stem three or more at each location as you move vertically up the stem. The leaves come from the stem one at a time as you move vertically up the stem, usually from alternating sides of the stem. The leaves come from the stem two at a time as you move vertically up the stem, usually from opposite sides of the stem.

Submerged Aquatic Vegetation - Leaf Directions

The key consists of a series of choices based on descriptive statements. To use this key, start at the first page and read the four statements pertaining to leaf arrangement. Decide which statement best describes the SAV you have collected and click on your choice. This will take you to the next pair of statements. Repeat the procedure until the bay grass in question is identified. You can then click on the name and additional information concerning the identification, distribution, ecological significance, similar species, and reproductive cycle of the plant will be provided. You will also be able to view pictures of the given species and print a fact sheet guide for use in the field. Note: the number of choices at each step of the key varies depending on different characteristics that exist among SAV in Maryland.

If you reach a point in the selection of descriptive statements where neither of the statements apply, work your way back through the preceding pairs using the "back a level" link at the bottom of each page.

You can also get back to the beginning of the key at any time by using the "Submerged Aquatic Vegetation Identification" link in the navigation toolbar at the bottom of each page.

For some specimens, measurements and magnification may be necessary to make a decision between two choices.

After you have made an identification you can return to the first page of the key to identify additional SAV species.