EPOW - Ecology Picture of the Week

Palm on Stilts

Stilt Palm, Pandanus tectorius (Pandanaceae), Maui, Hawaii

Stilt palms form sets of stiff secondary roots on prop roots.  In this way, they gain a tight grasp on infirm substrates such as sand and loose volcanic soil.  This seems like a good adaptation to the island soils.  Stilt palms grow in upper beach strand areas but occasionally get swept out to sea by storm tides and high winds.  

Its roots are covered by stiff spines, probably an anti-herbivore adaptation (so it won't be climbed upon or eaten).  Small mammals (exotic species on Hawaii) likely shelter in the cone created by the stilt roots.

Stilt palms on Hawaii are also called hala or screwpine (although it is not a pine), and the leaves are called lau hala.  The leaves are said to have been used by local peoples to make mats, fans, purses, and sails for canoes ... the leaves were dried and woven into many useful things ... the fruit and leaves were used medicinally ... and the roots were pounded, pressed, and heated to treat chest pains, stomach problems, and asthma.