ISI 2002-36. Pelargonium cotyledonis (L.) L’Her

The island of St. Helena played a role in history as the place of exile and burial of Napoleon following his defeat at Waterloo. Still administered by the U.K., it is also home to a unique flora and fauna, some of which is extinct and much of which is still endangered by centuries of overgrazing and deforestation. Among its rarities is Pelargonium cotyledonis, a natural bonsai with peeling bark and tidy, cordate, rugose, dark-green leaves and delicate umbels of white flowers. These flowers are radially symmetrical unlike those of most members of this usually zygomorphic genus. The petals are pure white, broadly obovate and form a bowl-shaped corolla. The flowers of most members of the genus are prominently marked with visible nectar guides that also reflect infrared wavelengths visible to pollinating bees. Perhaps nectar guides in P. cotyledonis would be revealed if photographed with infrared film. The anthers are delicate pink before dehiscence. Situated between Africa and South America, at 16°S, 5°W, St. Helena experiences a subtropical maritime climate. Therefore, P. cotyledonis is favored by cool but frost-free winter conditions with regular watering and drier, partly shaded conditions in summer but without excessive heat. Partial or total defoliation during summer dormancy is to be expected. HBG 85211, from controlled pollination of plants originally grown by Gary James in 1995 from seed from the Department of Agriculture of St. Helena. $15.

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Photo © 2002 by John N. Trager. Images may not be used elsewhere without permission.

Published in the Cactus and Succulent Journal, Vol. 74 (2), March - April, 2002