Lo'ulu (Pritchardia napaliensis)
|Listed||October 10, 1996|
|Description||Small tree with about 20 leaves and an open crown.|
|Habitat||Ranges from lowland dry to mesic forests to montane wet forests.|
|Threats||Habitat degradation through grazing by goats and pigs; seed predation by rats; competition with introduced exotics.|
Pritchardia napaliensis, a variety of lo'ulu and a member of the palm family (Arecaceae), is a small tree between 13 and 20 ft (4 and 6 m) in height with about 20 leaves and an open crown. This palm has a slender trunk about 8 in (20.3 cm) in diameter and green leaf blades 33.5 in (85.1 cm) long that are almost flat, if the longitudinal folds are discounted. The lower leaf surface is covered with elliptic, pale, thin, flexible, and somewhat translucent scales with fringed margins. Upon maturity, the leaves are almost smooth and the leaf segments are lax, flexible, and droop with increasing age. The flowers are arranged in branched clusters about 5.5 in (13.9 cm) long that are equal or shorter in length than the leaf stalks. Each flower is associated with a small, bristly bract. Bracts associated with the flowers or flower stalks are sparsely and inconspicuously coated with scales that are usually lost at maturity. The black fruits are 0.7-0.9 in (1.8-2.3 cm) long, 0.6-0.7 in (1.5-1.8 cm) in diameter, and inversely egg-shaped. This species is distinguished from others of the genus that grow on Kauai by having about 20 flat leaves with pale scales on the lower surface that fall off with age, inflorescences with hairless main axes, and globose fruits less than 1.2 in (3 cm) long.
P. napaliensis typically grows in a wide variety of habitats and elevations. Habitats range from lowland dry to mesic forests to montane wet forests dominated by either lama or kukui, 'ohi'a, and uluhe; elevations range from 500 to 3,800 ft (152 to 1,158 m). Associated plant species include hala pepe, kopiko, Cordyline fruticosa (ti), Cheirodendron trigynum ('olapa), and Ochrosia sp. (holei)
P. napaliensis is known from three locations on the island of Kauai on state-owned land. These occur at Hoolulu and Waiahuakua Valleys in the Hono O Na Pali Natural Area Reserve and Alealau in Kalalau Valley, within or close to the boundaries of Hono O Na Pali Natural Area Reserve and Na Pali Coast State Park. This species is not known to occur anywhere else.
The largest population in Hoolulu Valley contains between 60 and 80 plants, and the two other populations each contain three or fewer plants, giving a total of fewer than 90 known individuals for this species.
Major threats to P. napaliensis include habitat degradation through grazing by goats and pigs; seed predation by rats; competition with the introduced exotics air plant, daisy fleabane, lantana, common guava, and possibly C. fruticosa (ti); and a risk of extinction from naturally occurring events and reduced reproductive vigor due to the small number of remaining populations and individuals.
The Kalalau Valley population of P. napaliensis is threatened by feral pigs, and deer may forage on the plants in other locations. The largest population at Hoolulu Valley is threatened by goats. Rats threaten two of three populations by predation of their flowers and fruit.
Daisy fleabane threatens the Alealau population; air plant, an herb which occurs on all the main islands except Niihau and Kahoolawe, threatens the Alealau and Hoolulu. Lantana and common guava threaten the Hoolulu Valley population. Ti, a shrub that forms dense stands, may compete for space with the Hoolulu Valley population.
Conservation and Recovery
P. napaliensis has been successfully propagated, and more than 15 plants were in cultivation on the grounds of the National Tropical Botanical Garden.
The state has fenced the Hono O Na Pali Natural Area Reserve population to protect it from imminent destruction by goats and pigs. The enclosed area should be surveyed and managed to reduce the following alien plant species: air plant, daisy flea-bane, lantana, common guava, and ti.
U.S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N.E. 11th Ave.
Portland, Oregon 97232-4181
U.S. Fish and Wildlife Service. 1988. "Kauai II: Addendum to the Recovery Plan for the Kauai Plant Cluster." U.S. Fish and Wildlife Service, Portland, Oregon. 84+ pp.
"Lo'ulu (Pritchardia napaliensis)." Beacham's Guide to the Endangered Species of North America. . Encyclopedia.com. (November 14, 2018). https://www.encyclopedia.com/environment/science-magazines/loulu-pritchardia-napaliensis
"Lo'ulu (Pritchardia napaliensis)." Beacham's Guide to the Endangered Species of North America. . Retrieved November 14, 2018 from Encyclopedia.com: https://www.encyclopedia.com/environment/science-magazines/loulu-pritchardia-napaliensis