Toromiro tree (Sophora toromiro)
|Size||Height: up to 5 m (2)|
Main stem diameter: 10 - 20 cm (2)
Classified as Extinct in the Wild (EW) by the IUCN Red List 2002 (1).
Sophora toromiro is a small tree or shrub that no longer exists in its natural habitat. The bark of this shrub is a reddish brown colour and has vertical fissures (2). The long leaves are made up of small grey-green leaflets, which extend from either side of the leaf stem and are covered on the underside by silky hairs (3). When new, the leaflets are a yellowish to bright green colour and papery in appearance (2). The yellow flowers may be up to 3 centimetres long, there are 10 free stamens per flower and the thin ovary is particularly distinctive being 1.6 centimetres long and densely covered with small white hairs (2).
Once endemic to Easter Island (Rap Nui) in the South Pacific; possibly the remotest area of inhabited land on the planet (2). The native habitat of the island has been all but destroyed and this tree only persists in cultivation in a handful of botanic gardens and private collections around the world (2).
The original habitat of Easter Island is thought to have been low scrub and woodland with palm thicket (4).
The toromiro tree was already rare by the time European settlers arrived on Easter Island in the 1700s, and very little is known about this tree's natural ecology (4).
The native flora of Easter Island has been decimated over the centuries ever since the first settlers arrived on this remote island. Forests were cleared for timber and agriculture and by the time the first European explorers arrived on the island there were no large trees to be seen (4). The introduction of livestock in 1866 was a further blow, as sheep, cattle and rabbits stripped the land of its remaining native plants (4). The last recorded specimen of Sophora toromiro was seen growing on the inner slopes of the Rano Kau volcano crater, but this last tree was cut down for firewood in 1960, and another part of Easter Island's floral heritage was lost (4).
The toromiro tree persists today only in cultivation. In 1955 - 56 a Norwegian archaeologist and explorer, Thor Heyerdahl, collected seeds from the last remaining Sophora toromiro tree, protected within the volcanic crater on Easter Island (4). It is thought that trees found today in European botanic gardens are all descended from this one specimen (4). Other toromiro trees are known from botanic gardens in Chile and Melbourne and from private collections. The Toromiro Management Group (TMG) is responsible for managing these collections to ensure that this tree is not lost forever. The TMG is a consortium of botanic gardens, geneticists, foresters and archaeologists working together to secure the future of the tree, and ultimately to re-introduce it to Easter Island (5).
For more information on the toromiro tree see the Toromiro Management Group:
Authenticated (9/5/03) by Gwilym Lewis, Royal Botanic Gardens, Kew.
- Endemic: a species or taxonomic group that is only found in one particular country or geographic area.
- Leaflets: the individual 'leaf-like' parts of a compound leaf.
- Ovary: in plants, known as the gynoecium, the female reproductive organs of a flower.
- Stamens: the male reproductive organ of a flower, it is made up of an anther (the pollen-producing organ) and a filament (stalk). (See http://www.rbgkew.org.uk/ksheets/pdfs/flower.pdf for a fact sheet on flower structure).
- IUCN Red List (January, 2003) www.redlist.org
- Mackinder, B & Staniforth, M. (1997) Sophora toromiro. Curtis's Botanical Magazine, 14(4): 221 226.
- Lobin, W. & Barthlott, W. (1988) Sophora toromiro: the lost tree of Easter Island. Bot. Gard. Conserv. News, 1 (3): 32 - 34.
- Maunder, M. (1997) Conservation of the extinct toromiro tree. Curtis's Botanical Magazine, 14(4): 226-231.
- Toromiro Management Group (January, 2003) http://www.rbgkew.org.uk/conservation/cpdu/Toromiro/toro_t1.html#Introduction