Sophora toromiro

Toromiro on Rapa Nui

The Toromiro ( Sophora toromiro ) is a species of the genus of the string trees ( Sophora ) in the subfamily of the Fabaceae ( Faboideae ). This rare species was temporarily extinct, is endemic to Easter Island.

Description

The Toromiro is a slow-growing, small tree or shrub with a height of probably up to 3 meters. "It is unclear whether the Toro Miro is a shrub or after some time to a tree grows ( such as the closely related, up to 10 meters Height -reach species Sophora microphylla and Sophora tetraptera ). " Archaeobotanical studies of the University of Reading, UK, lead to the conclusion that the plant originally in the peripheral areas of the once extensive palm forests grew on Easter Island as undergrowth. As can be concluded from the few preserved carvings in the ethnographic museums, the main trunk can reach a diameter of up to 30 centimeters, and possibly more. The gray - brown bark is smooth but densely covered with small, light gray appearing cracks. The unpaired pinnate leaves have at the bottom and the petioles a fine, silver-gray hair that is visible only in the enlargement, however; she lets the lower leaf surface appear brighter. The bright green leaves are single about 5 millimeters long and oval.

The solitary yellow flowers are about 2 inches long and have ten stamens. In up to 10 centimeters long, legumes develop four to five seeds.

History

The first written mention of Toromiro we owe Georg Forster, who discovered this species as a participant of the second Pacific voyage of James Cook ( 1772-1775 ) on Easter Island:

" Although we had rested a few times, we were finally able to reach the summit of the hill, from which we saw the western sea and at anchor ship. The hill was with bushy Mimosa [ Forster kept the Toromiro for a mimosa ] covered that grew to a height of eight or nine feet here, and some of the tribes had approximately the thickness of a male upper arm. "

Forster collected parts of plants for the herbarium of the British Museum of Natural History, which even today are in this collection.

The French explorer Jean -François de La Pérouse, who in 1786 visited Easter Island, writes:

" Here and there is growing while the Mimosa, but only in single thin shrubs, have their strongest branches never more than three inches in diameter. "

The paymaster William Thomson, on board the American ship Mohican visited Easter Island in 1886, told of an already largely destroyed flora as a result of browsing damage from pets:

" At various places.. . we found small collections of Edwardsia [ Thompson used the obsolete genus name " Edwardsia " for the Toromiro ], Broussonetia and Hibiscus, but all were dead, all their bark had been bitten off by the flocks of sheep that strayed over the whole island. None of these trees was higher than 10 feet and the thickest trunk, we found, had just over 5 inches in diameter. "

The archaeologist Alfred Métraux photographed in 1935 one of the last, at this time already almost extinct Toromiro in the bottom of the slope of the crater of Rano Kao. The black and white photo is now in the archives of the Musée de l' Homme in Paris. It shows ( with a squatting woman as a benchmark ) a bushy growing, still leafy plant of about two meters in height with multiple stems that have a maximum thickness of approximately 20 cm.

The botanist Efrain Volovsky collected in 1953 for the Botanical Garden of the University of Viña del Mar herbarium specimens and describes the plant species in the Rano Kao - probably the same one Métraux had seen - as a tree of 3 m in height and 25 cm trunk diameter.

According to legend, the Toro Miro tree Hotu Matua of was brought to Easter Island. Sophora toromiro but was detected in pollen archaeobotanical analysis of Easter Island 35,000 years ago, so it can safely be assumed that the plant has settled without human influence on Easter Island. A close relative of the Toro Miro, Sophora cassioides (synonyms: . Edwardsia cassioides Phil, Sophora microphylla Ait ) is now common even in Chile. The seeds of many Sophora species survive a longer stay in the salt water, so that the natural distribution by ocean currents, starting from the Chilean mainland, it is believed.

The hard and fine-pored, with increasing aging deep red darkens wood has been used in many ways in the Easter Island culture, as a building material for the production of domestic consumer goods and weapons, but mainly as a base material for ritual carvings ( Moai wooden figures, Rei - Miro, Ao and Rapa and Zeremonialstäbe and drumsticks ). The intensive human use probably contributed before the arrival of Europeans to the decline of the species. As the Easter island was used for a British- Chilean consortium intensive cattle grazing in the 19th and 20th centuries, the stock went out completely, because the introduced by the Europeans Pets grazed the bark of trees and shrubs. Thor Heyerdahl brought in his Easter Island expedition (1955 /56) seeds of probably the last surviving Toromiro tree from the crater of Rano Kau to Europe (possibly the same specimen, which Métraux had photographed twenty years earlier ). According to Heyerdahl's account of the plant was heavily damaged and almost stripped of all branches.

Preservation

Thor Heyerdahl sent collected in the Rano Kao six or seven seeds to Sweden, where they were handed over to the Botanical Garden in Gothenburg after a few detours. Just three years after the arrival they tried to draw plants. Five seeds were allowed to germinate the following year. For more cuttings plant specimens were collected, which passed on to other botanical gardens, raised there and propagated.

In the Botanical Garden Bonn is a copy, which presumably from the stock of Gothenburg from the years 1972 - 1975 dates. The plant is now about 1.5 m high and has been widely propagated. In winter, the trees are kept in a cool greenhouse at 10 to 15 ° C, in the frost-free time outdoors. The Toromiro thrives best in a calcium-poor, slightly acidic soil.

1993 Toromiro Management Group was founded, whose goal it was, Toro Miros to resettle on Easter Island. Its members included the Botanical Gardens in Bonn, Gothenburg and the Kew Garden in London and the Chilean Forest Service ( CONAF ) and other experts. 1995 180 seedlings were brought back from the Botanical Gardens in Bonn and Gothenburg and handed over to the Chilean Forest Service. The project rests now, since most of the plants died in quarantine from a fungal infection. Whether the resettlement ever succeed is doubtful because of the narrow genetic base.

The only currently growing on Easter Island Toromiro located in the garden of the governor, it is an imported from the Botanical Gardens in Viña del Mar, small specimen.

1990 succeeded the French botanist Catherine Orliac on wood samples from Gothenburg to identify the cellular structure of Toromiro microscopic, so now the authenticity of art objects of Easter Island is unequivocally possible.