No Common Name
|Listed||October 10, 1996|
|Description||Sprawling or rarely erect shrub to a small tree; branches bear short hairs; bears flowers.|
|Habitat||'Ohi'a-and mamane-dominated lowland and montane dry forests.|
|Threats||Heavy browsing and habitat modification by feral sheep and goats; competition from alien plants; habitat change due to volcanic activity; residential development; insects.|
Neraudia ovata, of the nettle family (Urticaceae), is a sprawling or rarely erect shrub to a small tree, with stems 3-10 ft (0.9-3 m) long, and branches bearing short, somewhat erect hairs. The alternate, thin, stalked leaves are smooth-margined, grayish on the undersurface, 2-5.5 in (5-14 cm) long and 0.8-2.6 in (2-6.6 cm) wide, and have spreading, curved, nearly translucent hairs. Male and female flowers are found on separate plants. Male flowers have extremely short stalks and a densely hairy calyx. Female flowers have no stalks and a densely hairy, boat-shaped calyx. The fruit is an achene (a dry one-seeded fruit that does not open at maturity). This species is distinguished from others in this endemic Hawaiian genus by the density, length, and posture of the hairs on the lower leaf surface; smooth leaf margin; and the boat-shaped calyx of the female flower.
N. pyrifolia was named by Charles Gaudichaud-Beaupre from material he collected in the early 1800s on the island of Hawaii. This name was determined to be invalid because its published description was inadequate. Gaudichaud-Beaupre named N. ovata from an additional specimen, and this has been maintained in the current taxonomic treatment for the species. H. A. Weddell considered this taxon a variety of N. melastomifolia, but this has not been upheld by other taxonomists. S. L. Endlicher and E. G. Steudel placed this species in the genus Boehmeria, but the current taxonomic treatment maintains Neraudia as an endemic Hawaiian genus. Harold St. John named a new species, N. cookii, from a collection by David Nelson on British captain James Cook's 1779 voyage to Hawaii. That specimen is considered to be N. ovata in the current taxonomic treatment.
N. ovata grows in open 'ohi'a-and mamane-dominated Lowland and Montane Dry Forests at elevations of 380 ft (116 m) at Kaloko and 4,350-5,000 ft (1,326-1,528 m) at Pohakuloa Training Area. Associated taxa include Reynoldsia sand-wicensis ('ohe), naio, huehue, kolea, and Christ-masberry, as well as the federally endangered Nothocestrum breviflorum (ai'ae) and Pleomele hawaiiensis (hala pepe), and other species of concern, including Capparis sandwichiana (pua pilo), Fimbristylis hawaiiensis, and Bidens micrantha ssp. ctenophylla (ko'oko'olau).
Historically, N. ovata was found on the island of Hawaii on the Kona coast from North Kona to Kau. One extant population of five individuals is known from privately owned land in Kaloko, North Kona. An additional population of six individuals was re-discovered in late 1995 at the boundary of the U.S. Army's Pohakuloa Training Area.
The major threats to N. ovata are heavy browsing and habitat modification by feral sheep and goats; competition from alien plants such as Christmas-berry, koa haole, and fountain grass; habitat change due to volcanic activity; residential development; insects, like spiralling whitefly (Aleurodicus dispersus ); and a risk of extinction from naturally occurring events and/or reduced reproductive vigor due to the small number of existing individuals in the two remaining populations.
Conservation and Recovery
As of May 1998, the Volcano Rare Plant Facility held two plants in their nursery; the National Tropical Botanical Garden had six. The U. S. Army is currently developing an endangered species management plan that will include fencing, ungulate control, and alien plant removal in the Pohakuloa Training Area. The Hawaii Department of Agriculture has conducted a very successful biocontrol program for the spiarling whitefly which has greatly reduced insect damage, although it remains a problem on certain preferred host plants during the summer and in windy coastal areas. Outplanting efforts look promising for areas in the Hawaii Volcanoes National Park, Pohakuloa Training Area, and Kaloko Dry Forest in sites free from the impact of feral ungulates and future residential development.
U.S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N.E. 11th Ave.
Portland, Oregon 97232-4181
U.S. Fish and Wildlife Service. 1998. "Big Island II: Addendum to the Recovery Plan for the Big Island Plant Cluster.: U.S. Fish and Wildlife Service, Portland, Oregon. 80 pp. + appendices.