CPC Plant Profile: `Hi `ihi
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Plant Profile

`Hi `ihi (Marsilea villosa)

This shot shows Hawaii's own "four-leaf clover", which is really a fern. Photo Credit: Nellie Sugii
  • Global Rank: G1 - Critically Imperiled
  • Legal Status: Federally Endangered
  • Family: Marsileaceae
  • State: HI
  • Nature Serve ID: 152634
  • Date Inducted in National Collection: 02/10/1987

Marsilea villosa is a fern found only in the Hawaiian Islands, restricted to areas with irregular flooding regimes. Currently, it is known from 3 populations of O`ahu and 2 population on Moloka`i. Many of the historic populations on O`ahu were destroyed by drainage of ponding areas, habitat degradation, competition from alien plants, off road vehicles and development. Marsilea villosa resembles a four-leaf clover, with four leaflets borne at the end of a leaf stalk. The plant occurs either in scattered clumps or as a dense interwoven mat, depending on the competition with other species for limited habitat resources. Marsilea villosa requires periodic flooding for spore release and fertilization, then a decrease in water levels for the young plants to establish, and finally dry soil for the plants to mature.

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Nature Serve Biotics
  • 05/02/2017

Marsilea villosa has been recorded from the islands of Niihau, Oahu, and Molokai. The only sizable population is on Oahu, at a site where the species dominates the bottom of an extinct volcanic crater. Elsewhere on Oahu and on Molokai, the species persists only in a few small populations. The status of the species on Niihau is unknown. As with other native Hawaiian plants from lowland dry habitats, M. villosa has suffered from development, agriculture, fire, and alien plants and animals.

David Orr
  • 01/01/2010

Encroachment of alien vegetation. Habitat degradation by off-road vehicles. Fire. Development. Small population size. Trampling by humans and animals. Browsing by feral animals. (USFWS 1996, 2001)

David Orr
  • 01/01/2010

O`ahu- Lualualei- 1 population O`ahu- Makapu`u- 1 population O`ahu- Koko Head- 1 population Moloka`i- Kamaka`ipo-1 population Moloka`i- Moki`o- 1 population Approximately 4000 plants total (USFWS 1996, 2001)

David Orr
  • 01/01/2010

Reproduction biology studies. Propagation-rhizomes and sporocarps. (USFWS 1996)

David Orr
  • 01/01/2010

O`ahu Lualualei- removal of cattle and monitoring Koko Head- barrier created around population. Removal of alien plant species. Monitoring. Moloka`i Kamaka`ipo- Adjustment of condominium and golf course plans by private developers. (USFWS 1996)

David Orr
  • 01/01/2010

Exclosures or barriers around the rest of the populations. Decrease human and animal disturbance. Control alien plant species. Fire protection. (USFWS 1996)

David Orr
  • 01/01/2010

Ex situ establishment in gardens. Seed banking. Physiological studies. Genetic studies. Propagation- germplasm preservation, increase numbers of individuals. (USFWS 1996)


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Taxon Marsilea villosa
Authority Kaulfuss
Family Marsileaceae
CPC Number 2808
ITIS 18001
Common Names Ihi La'au | 'ihi'ihi | villous waterclover
Associated Scientific Names Marsilea villosa
Distribution O`ahu- Koko Head, Lualualei, and MakapuuMoloka`i- Kamaka`ipo and Moki`o(USFWS 1996)
State Rank
State State Rank
Hawaii S1

Restricted to areas with irregular flooding regimes and low elevations. Grows in small shallow depressions in silty clay or sand common in dry areas of most islands where winter rains create seasonal pools (USFWS 1996).

Ecological Relationships

Common Name Name in Text Association Type Source InteractionID
Lead Institution State Reintroduction Type Year of First Outplanting

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