Conserving Samoa's Natural Heritage

Plant Conservation

Please visit the Vailima Botanical Gardens (VBG) to see and learn more about Samoa’s endemic flora! We are working closely with the Ministry of Natural Resources and Environment (MNRE) to develop theme gardens at the VBG for rare plants, medicinal plants, butterfly plants and ornamentals under the “Vailima Botanical Gardens Zoning Plan”. We have also recently (October 2022) opened a brand new wheelchair accessible trail that takes you from the entrance of the VBG to the Information Fale!

Introduction to Samoa’s plants

Samoa has around 770 species of native plants. Of this, there are around 225 species of fern and fern allies (plants that sit between being a true fern and a flowering plant), and about 550 species of flowering plants. As the “primary producers” plants form the habitat and food source for all our animals including birds, flying foxes, reptiles and insects and other invertebrates, so we need to look after them!

Of the flowering plants, around 1/3 are endemic (only found in Samoa) and 108 are considered rare and/or threatened (Whistler 2011). Orchids are the largest family of flowering plants in Samoa with about 101 species, but the largest genera are Cytrandra, Psychotria and then Syzygium.

Focus of our plant conservation work

We do our best to carry out our conservation actions both “in situ” (in the plant’s natural habitat) and “ex situ” (away from the plant’s natural habitat), as both methods are important to the survival of rare and threatened species. For “in situ”, (in  the plant’s natural habitat) we work closely with our partner villages to collect and propagate these rare plants in the village plant nurseries, so to keep the plant as close to their natural environments as possible. We also manage threats to plants, which include climate change, invasive species and human-impacts (e.g., logging, agricultural development etc).

For “ex situ” conservation, we collect as many rare and endemic plants as possible and propagate them in our rare plant nursery at the Vailima Botanical Gardens. Once these plants grow strong, we then transplant them into the Vailima Botanical Gardens or at the developing NUS Peace Garden. Without ex situ conservation, in the event of a natural disaster, such as a large cyclone, all the wild populations of the plant could be wiped out in its natural habitat, and we would lose that plant species forever. However, with ex situ conservation, we can safeguard species and ensure their survival, especially in the face of climate change induced weather changes and increased natural disasters.

SCS is currently working to conserve 8 rare endemic plants in total, 5 are included on the ‘Rare Plants of Samoa’ list (Balaka samoensis, Manilkara samoensis, Syzygium christophersenii, Syzygium vaupelii and Vavaea samoense) (Whistler 2011), along with 3 that are not included but are considered rare endemics by local environmentalists (Clinostigma samoense, Clinostigma savaiiense and Alectryon samoensis). Out of these 8 species, we have successfully collected 5 species (B. insularis, M. samoensis, C. samoense, C. savaiiense and A. samoensis). The three species that we have not managed to collect are due to a lack of data on locality, very isolated habitats that we have not been able to visit, rarity or possible extinction of the species.

We collect rare plants at a number of locations which include  a variety of vegetation communities: Mt. Le Pue/Mt. Vaivai and Malololelei on Upolu, and Mt. Matavanu/Safotu, Falealupo and Aopo on Savaii. While we mainly focus on rare endemic species (rare plants that are only found in Samoa), we also collect other rare species (found elsewhere other than Samoa), such as tatania (Acacia simplex) and vili (Gyrocarpus americanus), medicinal plants (such as matalafi (Psychotria species) and butterfly plants (such as talafalu (Micromelum minutum)). All plants will eventually be planted in the Vailima Botanical Gardens for safeguarding and to increase public awareness of these special species. Increasingly we are trying to propagate rare plants in village plant nurseries and build capacity of village communities to safeguard their own rare plants. Currently we are supporting nurseries in Falealupo, Aopo and Uafato and hope to do so in more villages in future.

Our plant conservation work has been supported by several donors, most notably Botanic Gardens Conservation International (BGCI), the Keidanren Nature Conservation Fund (KNCF), Franklinia Foundation, and the British High Commission in Samoa, as well as friends of Dr Art Whistler, the author of the “Flora of Samoa” who passed away from covid in April 2020.

Current theme gardens at the Vailima Botanical Gardens

In the Vailima Botanical Gardens the Samoa Conservation Society in partnership with the Ministry of Natural Resources and Environment are growing a series of theme plant collections. This is a long term project over a 10 year period (2020-2030) and will be developed in stages.

Currently (October 2022) the plant collections include:

  • Rare and threatened plants
  • Medicinal plants
  • Butterfly plants (about to commence)
  • Lowland rainforest (about to commence)
  • Coastal rainforest (about to commence)

Map of zone 1 of the garden development

Medicinal plants

Our medicinal plant collection is being developed in partnership with the Scientific Research Organisation of Samoa (SROS). Here are descriptions of some of the medicinal plants in the collection.

Avaava aitu (Macropiper puberulum)Uncommon in lowland to montane forest in Samoa. The only known use for this plant is medicinal. This plant is believed to have supernatural effects and is used to treat “ghost sickness” (ma’i aitu), as well as for the massage of ailments such as swelling and inflammations believed to be caused by the presence or actions of ghosts.
Aloalo Vao (Mussaenda raiateensis)This native Samoan plant is found in open secondary vegetation coastal and lowland areas. It is typically used for massage or treating inflammation.
Aloe (Aloe vera)This succulent is not found commonly in the wild but grown in cultivated home gardens. The sap is commonly used to treat cuts and burns.
Aoa (Ficus obliqua and F.prolixa)The two native banyan tree species are commonly found in lowland to montane forest where they towers over the canopy. The hanging roots are used in Samoan medicine to treat urinary tract problems and stomach aches.
Esi (Carica papaya)Papaya is typically cultivated around houses and in plantations for their fruit. It can be used for toothaches.
Fetau (Calophyllum inophyllum)This native tree is mainly found in coastal areas, and occasionally planted for shade. The wood is highly versatile and valued in Samoa. It can be used for the treatment of eye injuries and diarrhea.
Filimoto (Flacourtia rukam)This native tree can be found in secondary forest and disturbed areas in Samoa. The fruits are sometimes made into jam and is medicinally used to treat inflammation and skin sores.
Fīsoa (Colubrina asiatica)This native tree is common on sandy and rocky beaches, and can be found vine-like, climbing into the littoral forest canopy. The leaves were historically used as a soap due to its lather produced by the saponin chemicals. The leaves can also be used in a potion to treat post-partum sickness.
Futu (Barringtonia asiatica)This native tree is often dominant on undisturbed rocky shores all around Samoa. The seed can be grated and used as a fish poison or infused with other ingredients to apply to skin sores.
Gatae (Erythrina variegata)This introduced tree is found in littoral forest on rocky high island shores and sometimes inland in coastal and ridge forests. The leaves from this plant can be used to treat eye injuries, swelling and inflammation.
Ifi (Inocarpus fagifer)This ancient introduction is found cultivated in plantations but is also naturalized in native forests, particularly in wet soil. The seed is peanut-like and esteemed by Samoans. Scraped bark can be used to treat stomachache.
Lau ti (Cordyline fruticosa)This ancient introduction can be found as a shrub in primary and disturbed forests. The leaves are commonly used in making skirts and dance costumes, roofing thatch and food wrappers. The leaves can also be used medicinally to massage inflammation, headaches, and body aches.
Leva (Cerbera manghas)This native plant is commonly found in rocky or sandy shores. The fruit is reported to be poisonous, and the flowers are used as decoration. The leaves can be mixed with coconut oil and used to treat skin sores and fungal skin infections.
Mamala (Omalanthus nutans)This native shrub is common in abandoned plantations and secondary scrub in lowland forests. The leaves or scraped bark has been used to treat urinary tract infections and as a purgative to clean the digestive tract.
Masame (Glochidion ramiflorum)This native tree occurs in primary and secondary forest at all elevations, but most frequently in disturbed vegetation and on lowland lava flows. The scraped bark or crushed leaves is commonly used for mouth infections and bruises.
Matalafi (Psychotria insularum)This native plant is common in the understory of lowland and montane forests over 1000m elevation. The leaves of the matalafi are used for abscesses, swelling, infections, fevers, and body aches. It is also a popular treatment by traditional healers for illnesses attributed to ghosts (ma’i aitu).
Milo (Thespesia populnea)This native is related to the hibiscus. An infusion of the scraped bark was used to treat mouth infections and stomachache.
Moso’oi (Cananga odorata)An introduced tree with lovely scented flowers. The scraped bark is used to treat postpartum sickness, constipation, stomachache and mouth infections.
Namulega (Vitex trifolia)A small native tree with leaves that formerly were used to repel mosquitoes. The name literally means “mosquito turmeric”.
Nonu (Morinda citrifolia)A small introduced tree that is probably the most widely used medicinal plant in Polynesia used for many treatments including supernaturally induced ailments, stys, inflammation, boils etc.
Seasea (Syzygium corynocarpum)An ancient introduction used in traditional medicine to treat burns, skin sores and inflammation.
Talie (Terminalia catappa)A common coastal tree. An infusion of the bark is used to
treat mouth infections.
U’a (Broussonetia papyrifera) The introduced paper mulberry – the bark of which is used to make tapa cloth.