Kaulu

Pteralyxia kauaiensis

Description

Kaulu(Pteralyxia kauaiensis ) is a small tree in the dogbane family (Apocynaceae) that grows to a height of 10-26 ft (3-7.9 m). The leaves are dark green and shiny on the upper surfaces but pale and dull on the lower surfaces. They are generally egg-shaped and usually 4.3-8.7 in (10.9-22.1 cm) long and 1.6-2.6 in (4.1-6.6 cm) wide. The pale yellow flowers are trumpet-shaped, 0.3-0.5 in (7.6-12.7 mm) long, with each of the five lobes 0.1-0.2 in (2.5-5.1 mm) long. The paired fruits, of which usually only one matures, are drupelike, bright red, and fleshy.

The woody endocarp that encloses the single seed has two prominent central wings and two reduced lateral wings. This species differs from the only other member of this endemic Hawaiian genus in having reduced lateral wings on the seed.

Habitat

P. kauaiensis typically grows on the sides of gulches in diverse lowland mesic forests and sometimes in lowland wet forests at elevations of 820-2,000 ft (250-610 m). Associated vegetation includes hame, lama, lantana, 'oki'a, and 'ala'a.

Distribution

P. kauaiensis was known historically from the Wahiawa Mountains in the southern portion of Kauai.

This species is now known from the following scattered locations on private and state land on Kauai at elevations of 820-2,000 ft (250-610 m): Mahanaloa-Kuia Valley in Kuia Natural Area Reserve; Haeleele Valley; Na Pali Coast State Park; Limahuli Valley; the Koaie branch of Waimea Canyon; Haupu Range; Wailua River; and Moloaa Forest Reserve. There is also an undocumented sighting of one individual at Makaleha, above the town of Kapaa, making a total of nine known populations with an estimated 500-1,000 individuals.

Threats

The major threats to P. kauaiensis are habitat destruction by feral animals and competition with introduced plants. Animals affecting the survival of this species include feral goats, pigs, and possibly rats, which may eat the fruits. Fire and overcollecting for scientific purposes could threaten some populations. Introduced plants competing with this species include common guava, daisy fleabane, kukui, lantana, strawberry guava, and ti.

Conservation and Recovery

National Tropical Botanical Garden holds seeds in storage but has been unable to successfully propagate P. kauaiensis.

Contacts

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
(503) 231-6121
http://pacific.fws.gov/

Pacific Remote Islands Ecological Services Field Office
300 Ala Moana Blvd., Room 3-122
P.O. Box 50088
Honolulu, Hawaii 96850
Telephone: (808) 541-1201
Fax: (808) 541-1216

Reference

U. S. Fish and Wildlife Service. 25 February 1994. "Endangered and Threatened Wildlife and Plants; Determination of Endangered or Threatened Status for 24 Plants from the Island of Kauai, HI." Federal Register 59 (38): 9304-9329.