Lo'ulu (Pritchardia viscosa)
|Listed||October 10, 1996|
|Description||Small tree that reaches 10-26 ft (3-8m) in height; lower surface of leaf blades is silvery gray and covered with small scales.|
|Habitat||Lowland wet forest.|
|Threats||Unrestricted collecting for scientific or horticultural purposes; excessive visits by individuals interested in seeing rare plants; possible overcollection by plant enthusiasts.|
Pritchardia viscosa, a variety of lo'ulu, is a small tree in the palm family that reaches 10-26 ft (3-8 m) in height. The lower surface of the leaf blades is silvery grey and covered with small scales. The inflorescences are about the same length as the leaf stalks and consist of one to three loosely branched panicles, each about 6-8 in (15.2-20.3 cm) long. The flowers occur in two opposite rows and are extremely sticky and shiny. The elliptic, pear-shaped fruit are up to 1.6 in (4 cm) long and about 1 in (2.5 cm) wide. This species differs from others of the genus that grow on Kauai by the degree of hairiness of leaf lower surfaces and the main axis of the flower cluster, as well as the length of the flower cluster.
P. viscosa is found in an 'ohi'a-uluhe lowland wet forest in association with the plant species 'aiea, 'ahakea, hame, hapu'u, and kopiko.
Historically, P. viscosa was known only from the 1920 collection from Kalihiwai Valley on the island of Kauai. It was not seen again until 1990, when naturalist John Obata and National Tropical Botanical Garden botanist Ken Wood observed it in the same general area as Joseph Rock's type locality off the Powerline Road at 1,680 ft (512 m) elevation on state land. This population of one juvenile and two mature plants comprises the only known extant individuals; three additional plants from this population were destroyed by Hurricane 'Iniki in 1992.
Because of the small numbers of individuals in the only known population, this species is susceptible to stochastic extinction through a single violent natural event.
Unrestricted collecting for scientific or horticultural purposes and excessive visits by individuals interested in seeing rare plants are potential threats to P. viscosa, which has only one population of fewer than five individuals. Collection of whole plants or reproductive parts of the plants could damage the gene pool. This species has populations close to trails and roads that are easily accessible to possible overcollection by plant enthusiasts. At least one of the three remaining individuals has been damaged by spiked boots used to scale those trees and collect seeds and reference material. Rats are predators of their flowers and fruit.
Strawberry guava is known to pose a direct threat to all remaining plants, while Hilo grass threatens the Powerline Road population.
Hurricane 'Iniki destroyed half of the known individuals, and future hurricanes are always a threat.
Conservation and Recovery
This species has been successfully propagated from seed and tissue culture, and 20 plants are presently in cultivation.
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 viscosa)." Beacham's Guide to the Endangered Species of North America. . Encyclopedia.com. (April 20, 2019). https://www.encyclopedia.com/environment/science-magazines/loulu-pritchardia-viscosa
"Lo'ulu (Pritchardia viscosa)." Beacham's Guide to the Endangered Species of North America. . Retrieved April 20, 2019 from Encyclopedia.com: https://www.encyclopedia.com/environment/science-magazines/loulu-pritchardia-viscosa