ID Tips and Tricks

Leaf Arrangement

Leaf arrangement is a great way to identify plants. Here are common leaf arrangements:

Basal: Leaves come from base of plant
Alternate: Leaves come from stem one at a time, alternating sides
Whorled: Leaves come from stem three or more at one location
Opposite: Leaves come from stem two at a time from one location on opposite sides

Leaf Edges

Leaves come in many different sizes and shapes, and have different edges. Common margins include:

Smooth
Toothed
Spinescent

Flowers and Seeds

During reproductive season, most species will put out flowers, later turning into seed pods. This often occurs late spring- early October, depending on the species. The presence of flowers and/or seeds will help assist in identifying to the species level most of the time.

Salinity

The water type you are in will help narrow down your species search. There are more species typically found in freshwater than there are in brackish/salty waters.

MAP

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Wild Celery (vallisneria americana) seed pod

Eurasion milfoil (Myriophyllum spicatum)

Delaware ID Guide

Check out an ID guide that walks you through how to ID SAV, including a dichotomous key, and most common species found in Delaware.

Learn More

MACROALGAE

Macroalgae

SAV vs. Macroalgae

Submerged aquatic vegetation (SAV) are underwater plants that have roots, stems, and leaves, and they anchor themselves in the soil at the bottom. SAV needs sunlight to grow, so it is found in shallow, clear water. These plants also produce flowers and seeds, making them different from algae.

Macroalgae, often called seaweed, are plant-like organisms also found underwater. They are different from SAV in that they don't have roots or true leaves, and reproduce via spores. They attach to surfaces like rocks, pilings, and SAV leaves or drift freely in the water. They come in three main types, named for their colors: green, red, and brown. These organisms are important because they produce energy through photosynthesis, making them a key part of the food chain, however in waters that have excess nutrients they can become a problem. Click here for more information about macroalgae in Delaware.

How to ID Webinar

Learn to confidently identify Delaware's submerged aquatic vegetation using DeSSAV's new Delaware-specific identification guide. This webinar covers the basics of SAV identification, demonstrates how to use the guide, and shows how to contribute observations through iNaturalist to support statewide monitoring efforts.

DESPECIES

Common Delaware Species

Delaware’s waters are home to a variety of submerged aquatic vegetation (SAV) species. Some of these plants are native, meaning they naturally grow in this region and play an important role in supporting local ecosystems. Others are non-native, which means they were introduced from outside the area, often through human activity. Some non-native species are invasive, spreading quickly and outcompeting native plants for space, sunlight, and nutrients. This can harm local wildlife and disrupt the balance of the ecosystem. Non-native plants are managed by the state's Division of Fish and Wildlife.

Non-native plants can arrive in several ways, such as being accidentally introduced by boats or through the release of aquarium plants into waterways. To help protect Delaware’s aquatic ecosystems, it’s important to properly dispose of aquarium plants—never dump them into natural bodies of water. By being mindful, we can help keep native plant populations healthy and thriving.