Poa siphonoglossa

No Common Name

Description

Poa siphonoglossa is a perennial grass that grows in masses to a height of 13 ft (4 m). The short underground stems (rhizomes) form a hard base for the stems, which are flattened and heavily tufted. The thin leaf blades are less than 4 in (10 cm) long. The rushlike older stems have bladeless sheaths. P. siphonoglossa can be distinguished from Hawaiian bluegrass by its longer stems and shorter panicles.

In 1988 a specimen was collected from Kaulaula Valley in Puu Ka Pele Forest Reserve that shared characteristics of P. siphonoglossa and the closely related P. manii. Some botanists believe that these two species are actually different growth stages of a single species. Even if this is so, the species would remain extremely rare.

Habitat

P. siphonoglossa is one of a large number of species endemic to the Kokee area in the northwestern part of the Hawaiian island of Kauai. This area is roughly encompassed by the 8 sq mi (21 sq km) Kokee State Park. P. siphonoglossa grows on shaded slopes near ridge crests in moist 'ohi'a (Metrosideros polymorpha ) forests at elevations of 3,300-3,900 ft (1,000-1,200 m).

Distribution

P. siphonoglossa was first collected in 1910 at an elevation of about 3,300 ft (1,000 m) above the town of Waimea. This grass was known from five historical sites on Kaiui; three of which still have extant populations on state-owned land. Thirty plants occur at Kohua Ridge in the Na Pali-Kona Forest Reserve, ten plants in the Kuia Valley, and two plants at Kalalau. Specimens collected in 1988 from Kaulaula Valley in Puu Ka Pele Forest Reserve show characteristics of both P. siphonoglossa and P. mannii.

Threats

The main threat to P. siphonoglossa is habitat degradation by feral pigs and goats. Feral pigs have entered formerly secure habitats through trails and paths left by the logging industry and roads created when ditch and water diversion systems were built earlier in the twentieth century. Feral pig activities lead to the loss of plants through uprooting, erosion, and the invasion of alien plant species. At the Kohua Ridge site, pig activity has caused extensive erosion of the lower ridge. Disturbed areas are moving up the slope and approaching the P. siphonoglossa population, as well as the endangered P. sandvicensis. The area is also heavily invaded by prickly Florida blackberry.

In addition to this predictable threat, the low number of existing plants puts the species at risk of extinction through unpredictable natural or human events.

Conservation and Recovery

The National Tropical Botanical Garden has seeds in short-term storage. The Kauai District of the State of Hawaii's Division of Forestry and Wildlife has fenced a plant sanctuary project in the Kalalau Rim area.

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
Telephone: (503) 231-6121
http://pacific.fws.gov/

U. S. Fish and Wildlife Service
Pacific Remote Islands Ecological Services Field Office
300 Ala Moana Blvd., Room 3-122
P.O. Box 50088
Honolulu, Hawaii 96850-5000
Telephone: (808) 541-1201
Fax: (808) 541-1216
http://www.r1.fws.gov/pacific/

References

Cuddihy, L. W., and C. P. Stone. 1990. Alteration of Native Hawaiian Vegetation: Effects of Humans, Their Activities, and Introductions. Cooperative National Park Resources Study Unit, University of Hawaii Press, Honolulu.

Macdonald, G. A., et al. 1983. Volcanoes in the Sea. 2d ed. University of Hawaii Press, Honolulu.

Stone, C. P., and J. M. Scott, eds. 1985. Hawai'i's Terrestrial Ecosystems: Preservation and Management. Cooperative National Park Resources Study Unit, University of Hawaii Press, Honolulu.

U. S. Fish and Wildlife Service. 13 May 1992. "Determination of Endangered or Threatened Status for Six Plants from the Kokee Region, Island of Kauai, Hawaii." Federal Register 57 (93): 20580-20587.

Wagner, W. L., D. R. Herbst, and S. H. Sohmer. 1990.Manual of the Flowering Plants of Hawai'i. University of Hawaii Press and Bishop Museum Press, Honolulu.