Hedyotis parvula

No Common Name

Description

Hedyotis parvula is an erect or sprawling branched shrub of the coffee family with stems up to 12 in (30.5 cm) long. The leathery leaves are 1.6 in (4.1 cm) long and uniform in size along the stem. The white flowers consist of a funnel-shaped tube about 0.4 in (1 cm) in length with purplish pink-tipped lobes. The fruit is a round capsule that contains angled brown seeds. This species has been observed flowering in both winter and summer; flowering is induced by rain. It has also been known by the name Kadua parvula.

Habitat

H. parvula grows in dry habitat on rock outcrops, ledges, and at the bases of cliff faces. Associated plants include 'a'ali'i (Dodonaea viscosa ), alahe'e (Canthium odoratum ), and 'ala'ala wai nui or spur-flower (Plectranthus parviflorus ).

Distribution

H. parvula was known on Oahu from Makaleha Valley to Nanakuli Valley in the central and southern Waianae Mountains. This species was found in 1976 on Makua-Keaau Ridge and in 1986 on Makaleha Ridge; it has not been found anywhere else.

The four extant populations on federal land totaled 220-235 individuals in 1997. Two populations of 150 total individuals occur on Makua Military Reserve Reservation, one population of 60-75 occurs on Palikea Ridge between Nanakuli and Lualualei, and one population of 10 occurs west of Palawai Gulch.

Threats

Any surviving H. parvula plants are threatened by habitat degradation by feral pigs and competition with aggressive non-native plant species.

Two alien plants are colonizing the area where H. parvula is believed to survive. Christmasberry, an aggressive tree introduced to Hawaii before 1911, forms dense thickets and may also release chemicals that inhibit the growth of other species. Molasses grass, which ranges from the dry lowlands to the lower wet forests of the leeward ridges, grows in dense mats that smother native vegetation.

All the surviving populations are extremely vulnerable to extinction through unpredictable natural or human-induced events.

Conservation and Recovery

The U. S. Army has adopted a fire management plan that includes realigning targets and establishing firebreaks. Implementation of the plan may aid in protecting this species from fire. Completion of a boundary fence on the south and southeast perimeter of Makua Valley and continued goat control efforts, though limited, should help protect this species from further goat damage. Enclosures and fencing need to be constructed at other sites, particularly the Palikea Ridge population.

The National Tropical Botanical Garden and Lyon Arboretum are propagating this species.

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/

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

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.

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