Final Comprehensive Conservation Plan - U.S. Fish and Wildlife ...

Hakalau Forest National Wildlife Refuge
Comprehensive Conservation Plan
larger, measuring 13-34 in long and 2.8-8.7 in wide. The inflorescence is a cluster of 6-25 flowers.
Compared to other species within the genus, the flowers of C. platyphylla are small. The bases of the
flower parts (sepals, petals, and stamens) are fused together in a structure known as a hypanthium.
The petals are white or yellowish with magenta strips and there are five triangular sepals. The pale
orange berries measure 0.3-0.4 in long and 0.2-0.3 in wide (Mitchell et al. 2005).
Historically, C. platyphylla was known to occur in the following areas: Waipio Valley, Kohala
Mountains, Laupāhoehoe; in the mountains above Hilo, Pahoa, Glenwood, and Honaunau; and at the
unknown location named “Kalanilehua.” According to the Addendum to the Big Island Plant Cluster
Recovery Plan (1998a), two naturally occurring C. platyphylla populations consisting of nine
individuals existed in the late 20 th century. These occurred in the Laupāhoehoe NAR and along
Saddle Road. In 2003, six occurrences of C. platyphylla were known (Federal Register 2003b). More
recent estimates suggest that there are 4-6 populations consisting of 50-100 plants. In 2004,
2 individuals were found at a population near Kilau Stream and 11 plants were found in the
Laupāhoehoe NAR. No individuals are known from Hakalau Forest NWR. Additional surveys in the
historical range and likely habitat areas are needed to determine the exact distribution of the species
(Mitchell et al. 2005).
Montane wet „ōhi„a forests are the preferred habitat of C. platyphylla, although it can be found in
lowland areas. It has been reported to occur between 390-3,000 ft in association with hāpu„u, ho„i„o,
hame, „oha wai, pilo, and ha„iwale (USFWS 1998a).
Two critical habitat units were designated in 2003, encompassing 7,234 ac. The first unit is located
primarily within the Laupāhoehoe NAR, with a small portion in the northwest in the Hilo Forest
Reserve. The second unit is within the Wailuku watershed in the Hilo Forest Reserve (Federal
Register 2003b).
Competition with introduced plants has resulted in C. platyphylla population declines. Nonnative
mammals, such as rats and pigs, also threaten existing populations by modifying habitat and eating
the fruit (USFWS 1998a). Hawai„i‟s Comprehensive Wildlife Conservation Strategy (2005) and the
Addendum to the Big Island Plant Cluster Recovery Plan (1998a) also identify volcanic activity,
stochastic events, and reduced reproduction vigor as threats.
The downlisting criterion established in the Addendum to the Big Island Plant Cluster Recovery Plan
(1998a) requires 5-7 populations of at least 100 mature plants each that are sustained for a 5-year
period. The delisting criterion requires 8-10 populations of C. platyphylla with at least 200 mature
plants each. These populations must be sustained for 5 consecutive years.
4.9.7 Cyanea shipmanii
Cyanea shipmanii is a small, palm-like understory species. The shrub can be unbranched or have few
branches and reaches a maximum height of 13 ft. Cyanea shipmannii is characterized by its slender
stems and pinnately lobed leaves. The stalked leaves are deeply cut into 20-30 lobes per leaf
(Mitchell et al. 2005). Young plants have sharp projections on their stems and leaves, typically only
up to about 3.5 ft. This may be an evolved defense against flightless geese or ducks that once existed
on the island (Jeffrey, pers. comm.). The flowers of C. shipmanii have fine hairs and are grouped in
clusters of 10-15. The flower petals are whitish green and fused into a curved, five-lobed tube. The
orange berry is ellipsoid in shape (Mitchell et al. 2005).
Chapter 4. Refuge Biology and Habitats 4-63