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Plant Profile

Popolo`aiakeakua (Solanum sandwicense)

Closeup of leaves showing the dense stellate hairs. Photo Credit: S. Perlman
  • Global Rank: G1 - Critically Imperiled
  • Legal Status: Federally Endangered
  • Family: Solanaceae
  • State: HI
  • Nature Serve ID: 138358
  • Lifeform: Subshrub, Shrub
  • Date Inducted in National Collection:

There are two threatened Solanum species endemic to Hawaii (U.S. Fish and Wildlife Service [USFWS] 2001). Historically, Solanum sandwicense was known from 12 locations on the islands of Oahu and Kauai, but now 5 populations exist only on the island of Kauai. All populations of S. sandwicense have become extinct on Oahu due to urbanization, feral pigs, competition with introduced plants and from naturally occurring events such as landslides (USFWS 1995). S. sandwicense, a member of the nightshade family (Solanaceae), is a large sprawling shrub that can grow up to 4 meters (13 ft) tall. This shrub has a trunk that can grow up to 15 centimeters (6 in) in diameter. With the exception of some young parts, the rest of the plant is very pubescent with yellowish stellate hairs that are dense on the lower leaves, and sparser on the upper surface. The flowers of S. sandwicense are perfect (having both male and female reproductive parts) that have bent peduncles so the flowers face downward. These actinomorphic (radially symmetrical) flowers have white erect filaments, yellow anthers, and a pale green stigma (Wagner et al. 1999).

Where is Popolo`aiakeakua (Solanum sandwicense) located in the wild?


S. sandwicense inhabits diverse lowland to montane mesic forests, 760 to 1,220 (2,500 to 4,000 ft) meters elevation.Associated species of S. sandwicense include Acacia koa (koa), Metrosideros polymorpha (ohia), Dicranopteris linearis (uluhe), Psychotria hexandra (Kopiko), and Melicope sp. (alani) (USFWS 1995).


S. sandwicense was once found on the islands of Kauai and Oahu, the last remaining Oahu population died in the 1990s. (Wood et al. 2002)

States & Provinces:

Popolo`aiakeakua can be found in Hawaii

Which CPC Partners conserve Popolo`aiakeakua (Solanum sandwicense)?

CPC's Plant Sponsorship Program provides long term stewardship of rare plants in our National Collection. We are so grateful for all our donors who have made the Plant Sponsorship Program so successful. We are in the process of acknowledging all our wonderful plant sponsorship donors on our website. This is a work in progress and will be updated regularly.

Conservation Actions

Nature Serve Biotics
  • 05/02/2017

Endemic to the islands of Kauai, Oahu, and Hawaii. It has not been seen on Hawaii since the 1800's. On Oahu, no wild plants are known to be extant (although plants propagated from an Oahu population still exist in cultivation). On Kauai, fewer than 20 individuals are known. The species is threatened by feral pigs and goats, and a number of alien plant species.

  • 01/01/2010

Threats to S. sandwicense include habitat degradation by feral pigs, and competition with non-native plant species. This species is also threatened by over collecting, fire, stochastic extinction, and reduce vigor due to the small number of existing indi

  • 01/01/2010

Number of Populations: 5 (USFWS 2001) Number of Plants: 13-14 (USFWS 2001)

  • 01/01/2010

The seeds of S. sandwicense have been tested by the Center for Conservation Research and Training (CCRT), finding that they are orthodox and can tolerate freezing. The laboratory germination time was nine weeks (Yoshinaga 2002).

  • 01/01/2010

The Kokee Resource Conservation Program (KRCP) is a volunteer based alien species control program. KRCP has improved the status of S. sandwicense population by weeding out Rubus argutus (Fay et. al., 2001). The last wild individual of S. sandwicensis died on Oahu in the early 1990s. The staff at the NTBG had made several conservation collections of seed before its death, which are now cultivated. The National Tropical Botanical Garden (NTBG) currently has ex situ holdings of 1,433 seeds in its seed bank, which represents all five populations (including the Oahu population that is now extinct) (Wood et. al., 2002). In addition, there are 20 plants that represent three out of the five populations growing in the grounds of the botanical garden. From those 20 plants in the grounds of NTBG, eight plants are from unknown localities

  • 01/01/2010

1. Propagation efforts and the maintenance of adequate stock ex situ should be undertaken. 2. Pollination biology and studies are needed. 3. Map genetic diversity in the surviving wild populations of S. sandwicense. Recommendations derived from M.H. Chapin, M. Maunder, and USFWS (1995).

  • 01/01/2010

1. Establish secure ex situ stocks with full founder representation. 2. Develop proper horticultural protocols and pest management for S. sandwicense. 3. Surveys ex situ holdings so that molecular fingerprinting can be done. Recommendations derived from M.H. Chapin and M. Maunder.


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Taxon Solanum sandwicense
Authority Hook. & Arnott
Family Solanaceae
CPC Number 4037
ITIS 30485
Duration Perennial
Common Names Aiakeakua | Hawaiian horse-nettle | popolo | popolo'aiakeakua | Hawai'i horsenettle
Associated Scientific Names Solanum sandwicense | Solanum hillebrandii | Solanum kavaiense
Distribution S. sandwicense was once found on the islands of Kauai and Oahu, the last remaining Oahu population died in the 1990s. (Wood et al. 2002)
State Rank
State State Rank
Hawaii S1
Ecological Relationships


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