Olearia Moench (1802), in the family Compositae, contains around 100 species in the south Pacific, Australia and New Zealand. Description Trees to 10m or large shrubs, rarely herbaceous. The leaves are alternate or opposite, evergreen, simple or toothed, leathery, usually white beneath. The flowerheads are mostly small, in flattish clusters at the ends of the branches, white, pale purple, pink, or blue. Phyllaries in several rows, usually papery at the tip. Ray florets often numerous, usually narrow, sometimes absent. Stamens 5. Ovary inferior, with 1 cell and 1 ovule; style 1, forked, flattened towards the tips. Pollination is by insects. The fruits are 1-seeded, topped by a pappus of unequal, barbed bristles. Key Recognition Features Leathery leaves, whitish beneath; daisy flowers in flattish heads. Evolution and Relationships The Compositae is discussed under Senecio. Olearia is related to Microglossa DC from Africa, which is close to Aster L. and includes some shrubs and climbers. It is also related to Baccharis L., a mainly shrubby genus from South America. Celmisia Cass. from Australia and New Zealand is close in its usually white flowers and silver-backed leaves, but is mostly herbaceous. Olearia species with few, large flowers, such as O. chathamica Kirk, are found on the coasts and offshore islands of
New Zealand. Ecology and Geography In forest and scrub in New Zealand (around 30 species), Australia, and New Guinea. Comment Several species are grown as ornamentals in cool maritime climates and may form useful, salt-tolerant hedges. The genus is named after Olearius, Adam Olschlager (d.1671), a German botanist. |
