Lo'ulu (Pritchardia affinis)
|Listed||March 4, 1994|
|Description||Fan-leaved palm tree with pale or pinkish soft wool covering and scattered yellowish scales.|
|Habitat||Coastal mesic forests at coastal sites or in gulches further inland.|
|Threats||Predation on seeds by roof rats; development of land where individuals grow; limited numbers.|
Lo'ulu is a fan-leaved palm tree 33-82 ft (10-25 m) tall, with pale or pinkish soft wool covering the underside of the petiole and extending on the leaf blade. The wedge-shaped leaf has a green and smooth upper surface and a pale green lower surface with scattered yellowish scales. The branched, hairless flower clusters are located among the leaves. Each flower comprises a cup-shaped, three-lobed, calyx; three petals; six stamens; and a three-lobed stigma. The spherical fruit is about 0.9 in (2.3 cm) in diameter. The species is distinguished from other species of Pritchardia by the long, tangled, wooly hairs on the underside of the petiole and the base of the lower leaf blade. Also distinctive are the stout, hairless flower clusters, which do not extend beyond the wedge-shaped leaves, and the smaller, spherical fruit.
This species typically grows in coastal mesic forests at coastal sites or in gulches further inland, at elevations between sea level and 2,000 ft (610 m), possibly associated with brackish water. Native associated species are unknown since all trees are found in cultivated zones, which have long been cleared of their native cover.
Scattered individuals of the species can be found throughout much of the historically known coastal range at Kiholo; at Kukio; near Palani Road; on Alii Drive in Kukio; in Captain Cook; at Hookena; at Milolif; and at Punaluu. Most plants grow within areas of human habitation or development, and these trees may have been cultivated rather than having occurred in these areas naturally. Eight or more populations, which comprise a total of 50-65 extant individuals, are scattered along the western coast of the Island of Hawaii and within Hawaii Volcanoes National Park. Individuals are scattered in urban areas near Kihilo, Kukio, Palani Road, Kailua, Captain Cook, Milolii, and at Punaluu at unspecified sites. The species also occurs along the eastern portion of Hawaii Volcanoes National Park. Three trees still survive along Kalapana Trail at about 1,000 ft (305 m). These individuals appear to have been planted. Several other individuals were planted near Wahaula, but were destroyed by lava in the 1980s.
P. affinis grew in areas that have been cleared for urban development and agriculture. In 1921, it was indicated that Hawaiians used the fruits as a food source. Very few individuals occur in natural conditions, and those that do occupy prime areas for development near Kailua-Kona. Development and human disturbance are serious threats. Accompanying human habitation, black roof rats consume fruits and seeds. Feral pigs root and destroy seedlings, preventing regeneration. Fire is a serious threat. Lava flowing from Kilauea destroyed several individuals near Wahaula in 1989. The small number of populations and individuals may compromise the reproductive viability of these individuals and increase the vulnerability of the taxon to random events. Although lethal yellow has not been detected in Hawaii, introduction of this bacterialike organism that often attacks palms could prove devastating to the few remaining Pritchardia plants.
Conservation and Recovery
The National Tropical Botanic Garden has propagated the taxon and has a number of young plants growing at Lawai, Kauai. Volcano Rare Plant Facility has germinated seed and, as of 1995, has about 200 individuals about 1-2 in (2.5-5.1 cm) high, growing vigorously in the greenhouse. The division of forestry and wildlife has had no trouble germinating and growing P. affinis, which several nurseries apparently grew for retail before the taxon was listed as endangered. Twenty seedlings were planted at Kona Coast State Park. Hawaii Department of Fish and Wildlife also has approximately 100 seedlings in its nursery.
Protection from development, pigs, and rats is necessary. The rare natural habitat of this species should be protected. Propagation and maintenance of ex situ genetic stock should continue. Outplanting of propagated plants will likely be necessary in order to augment populations. Efforts to prevent spread of lethal yellow to Hawaii should continue.
U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6121
Senior Resident Agent Office
U.S. Fish and Wildlife Service
300 Ala Moana Boulevard, Room 7-235
P.O. Box 50223
Honolulu, Hawaii 96850-5000
Telephone: (808) 541-2681
Fax: (808) 541-3062
U.S. Fish and Wildlife Service. 4 March 1994. "Endangered and Threatened Wildlife and Plants; Determination of Endangered or Threatened Status for 21 Plants from the Island of Hawaii, State of Hawaii." Federal Register 59 (43): 10305-10325.