Narrowleaf gulfweed

Sargassum natans

Family Sargassaceae - marine algae (brown)

Marine brown algae; free floating; color orange to brown; plant body (thallus) with many branches, rounded in cross-section; branches bear flat, elongate, leaf-like organs (blades) with serrated margins on a small rounded stalk; spherical, air-filled sacs (bladders) on short stalks in axils of leafy part, sacs with small spine-like projection; blades 2.5-7 cm (up to 2 3/4 in) long, 2-3.5 mm (to 1/7 in) wide; 1 individual may reach up to 50 cm (20 in).
Similar Species
The broadleaf gulfweed has wider blades with a prominent midline and no spine-like projections on its air bladders.
Free floating, washes up in masses on the beaches starting around mid-spring, also found in masses floating in the bays.
Maximum Size
Other Common Names
Previous Scientific Names




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