Key to Florida's Seagrasses

(with thanks to Florida Department of Environmental Protection's Bureau of Protected Species Management, from whom I lifted this key and graphics)

Vegetative Key

Plants with flat leaf blades ...................................... 1
Plants with round or cylindrical leaf blades ...................... Syringodium filiforme (syn: Cymodocea filiformis)

la. Leaves paddle shaped, each associated
with 2 scales at the base ....................................2. Halophila species

lb. Leaves in a pseudowhorl, each with 2 scales at the base and two scales halfway up the petiole or leaf stem .......................... 3. Halophila engelmannii


1c. Leaves strap-like or at least linear .......................... 4

2. Leaves rounded, generally oval in shape, secondary veins
at an angle greater than 45 degrees, leaf margins
with minute serrations; annuals from seeds ..................... Halophila decipiens Pictures of Halophila decipiens


2. Leaves with a pointed tip, secondary veins approximately 45 degrees or less,
elongated, entire; perennials .................................. Halophila johnsonii


4. Leaf blades greater than 3 mm in width,
generally about 1 cm wide, plants with scaly rhizomes .......... Thalassia testudinum


4. Leaf blades generally less than 3 mm in width .................. 5

5. Leaves clustered from a distinct node on a rhizome,
leaf tip is truncated .......................................... Halodule wrightii


5. Leaves, threadlike from a branched stem,
leaf tip is pointed, can be found in active growth
throughout the year ............................................ Ruppia maritima


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