Viola kauaensis var. wahiawaensis
|Listed||October 10, 1996|
|Description||A perennial, herbaceous wildflower with widely spaced leaves, and two types of flowers, conspicuous, open flowers and smaller, unopened flowers.|
|Habitat||Open bog and wet shrubland.|
|Threats||Naturally occurring events, small number, habitat degradation through the rooting activities of feral pigs, competition with alien plants.|
Viola kauaensis var. wahiawaensis (Nani wai'ale'ale), a member of the violet family (Violaceae), is a perennial herb with upward curving or weakly rising, hairless, lateral stems about 4-20 in (10-51 cm) long. The kidney to heart-shaped leaves are usually 0.8-2 in (2-5 cm) long, 1.4-2.4 in (3.5-6 cm) wide, and widely spaced. The toothed leaf blades are unlobed or rarely three-lobed, hairless or covered with a few minute hairs, with a broadly wedge-shaped base. The solitary flowers are borne in the leaf axils. Two types of flowers are present. One is self-pollinating and does not open, while the other opens and requires cross-pollination. The flowers that open have hairless petals that are white on the upper surface and purple or blue to white on the lower surface. These petals are narrowly spatula-shaped, the upper petals measuring about 0.6-0.7 in (1.5-1.8 cm) long, the lateral ones about 0.7-0.9 in (1.8-2.3 cm) long, and the lower ones about 0.7-1 in (1.8-2.5 cm) long. The non-opening flowers usually occur on short lateral stems. Their greenish petals are hairless, the upper ones being three-lobed and about 0.04-0.06 in (1-1.5 mm) long. The fruit is a deeply lobed capsule 0.3-0.5 in (7-13 mm) long. The two recognized varieties of this species, var. kauaensis and var. wahiawaensis, both occur on Kauai; the former has heart-shaped to truncate leaf bases, and the latter has broadly wedge-shaped leaf bases. The species is distinguished from others of the genus by its non-woody habit, widely spaced leaves, and two types of flowers, conspicuous, open flowers and smaller, unopened flowers.
The Viola kauaensis var. wahiawaensis occurs in open bog and wet shrubland. It occurs in tropical montane regions at elevations of 2,100-2,840 ft (640-865 m).
Viola kauaensis var. wahiawaensis is known only from the Wahiawa Mountains of Kauai on privately owned land. This species is not known to have occurred beyond its current range. Less than 100 individuals are known to remain in Kanaele Swamp (often referred to as Wahiawa Bog), an open bog at about 2,100 ft (640 m) elevation surrounded by low scrub of 'ohi'a, uluhe, and 'ohi'a ha. Another eight plants occur at about 2,840 ft (867 m) elevation on a nearby ridge between Mount Kapalaoa and Mount Kahili in wet shrubland dominated by uluhe (Diplopterygium pinnatum ) ground cover, with scattered 'ohi'a and Syzygium sp.
The primary threats to Viola kauaensis var. wahiawaensis are a risk of extinction from naturally occurring events and reduced reproductive vigor due to the small number of existing populations and individuals, habitat degradation through the rooting activities of feral pigs, and competition with alien plants such as Juncus planifolius and Pterolepis glomerata.
Conservation and Recovery
All of the known critical habitat of the nani wai'ale'ale is on privately owned land, and is potentially at risk from development and other threatening activities. Its critical habitat should be acquired and designated an ecological reserve, or conservation easements negotiated with the landowners. The critical habitat must be managed to reduce the threats to the Viola kauaensis var. wahiawaensis. The plants should be enclosed within protective fencing, and the abundance of herbivorous mammals decreased or eliminated. Invasive alien plants must also be decreased or eliminated from the local habitat. The populations of the Viola kauaensis var. wahiawaensis should be monitored, and research undertaken into its biology and habitat needs.
U. S. Fish and Wildlife Service
Pacific Islands Ecoregion
300 Ala Moana Boulevard, Room 3-122,
P.O. Box 50088
Honolulu, Hawaii 96850
Telephone: (808) 541-3441
Fax: (808) 541-3470
U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Building
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
Telephone: (503) 231-6121
U.S. Fish and Wildlife Service. 10 October 1996. "Endangered and Threatened Wildlife and Plants; Determination of Endangered or Threatened Status for Nineteen Plant Species From the Island of Kauai, Hawaii." Federal Register 61 (198): 53070-53089