Pairs of leaves on petioles along a rhizome rooted in sand.
Leaves are from 1.8 - 5 mm wide, obovate to spatulate. Male and female
flowers are produced infrequently on separate plants. Branching leads to
intertwined plants in a meadow or runners colonizing new substrate. Bright
Leaves are crisp, remaining erect out of water; midrib and
margin thickened. Leaf surface smooth, shiny, margin without spines or
Forms patches or meadows in sand with only the leaves
visible, often covered by epiphytes. Found subtidally at 0.5 - 4 m in sandy
areas surrounding reefs, in bays or fishponds.
Hawai‘i: O‘ahu, Maui, Moloka‘i, Kau‘i,
Mechanism of Introduction: Endemic to
Halophila hawaiiana is a relatively rare subtidal
seagrass, a flowering plant with roots that hold sediments. Like other
seagrasses, Halophila meadows support a rich community of associated
organisms in sediments and on the leaf blades, providing food and shelter
for more mobile organisms such as fish and crustaceans. Halophila
hawaiiana is part of the Hawaiian green turtle’s diet.