Hawaiian Rare Plant Program
What is the Hawaiian Rare Plant Program?
The Lyon Arboretum Hawaiian Rare Plant Program (HRPP) utilizes micropropagation, seed banking and greenhouse propagation as
horticultural tools for plant germplasm conservation. The objectives for this project are to (a) prevent further extinction of native
Hawaiian plant species and Polynesian introduced crop plants, (b) propagate plants for approved restoration projects and garden
use, and (c) initiate and maintain an in vitro germplasm collection of these “critically endangered” Hawaiian plants. HRPP’s primary
focus is to preserve the plants that are most at risk of becoming extinct, such as the native plant species that have 20 or fewer rep-
resentatives left in the wild. Lyon Arboretum works cooperatively, in joint conservation efforts with other Hawaiian botanical gar-
dens, various state and federal agencies officially concerned with plant conservation and endangered species, private conservation
agencies, environmental organizations, and major private landowners.
Harold L. Lyon Arboretum-University of Hawai‘i at Mänoa, 3860 Mänoa Road, Honolulu, Hawai‘i 96822, Phone (808)-988-0470
The Micropropagation Laboratory
To date, the Lyon Arboretum Micropropagation La-
boratory has successfully grown over 300 Hawaiian plant taxa using micropropagation techniques. Cur-
rently, we house more than 17,526 plants, consisting of 228 native plant taxa (of which 141 are federally
listed as endangered/threatened). This includes over 70 varieties of taro, and 15+ varieties of banana. Last
year alone, over 1,300 plants were produced via micropropagation for various conservation projects, en-
tailing restoration & reintroduction, research and education, as well as botanical and display gardens and
The Seed Conservation Laboratory
In the Seed Lab, over 8 million seeds are banked, representing more than 400 taxa of native
Hawaiian plants. Of these, about half are federally listed as threatened or endangered. Prior to
the establishment of the Seed Conservation Lab in 1995, little was known about how well
seeds of native Hawaiian plant species might be stored. However, with our current knowledge,
we now know that only about 6% of Hawaiian taxa have recalcitrant seeds.
We continue to conduct research on our existing collections, testing viability under different
conditions at various intervals over the years, with data for some species that have been
stored for 15 years or more. We have added several species of ferns to our collection and are
beginning to study spore storage potential. We also continually seek to make collections of seeds for research on species that we
do not understand as well yet.
The greenhouse receives seeds and various types of vegetative cuttings from the wild, which are
propagated on the mist bench or on regular benches. The greenhouse is critically important for tran-
sitioning sterile micropropagation and seed growth chamber germinated plant cultures from the lab
environment to the greenhouse. These plants and seedlings are “acclimatized” (acclimated to the
outside greenhouse growing conditions), hardened, and eventually returned to their natural environ-
ment via outplanting restoration efforts.