Laurus
| Laurus | |
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| Laurus novocanariensis forest, Los Tilos, La Palma | |
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| Genus: | Laurus |
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Laurus azorica Azores Laurel | |
- This article is about the Laurus genus. For information on the church hierarch, see Metropolitan Laurus. For the saint, see Florus and Laurus.
Overview
Laurus is a genus of evergreen trees belonging to the Laurel family, Lauraceae. The genus includes three species, whose diagnostic key characters often overlap (Mabberley 1997).
- Laurus azorica (Seub.) Franco, Known as Azores Laurel, or by the Portuguese names Louro, Loureiro, Louro-da-terra, and Louro-de-cheiro, is native to the laurisilva forests of the Azores, and also locally introduced in Cortegada Island, Spain.
- Laurus nobilis L., known commonly as Bay Laurel, True Laurel, Sweet Bay, Grecian Laurel, or simply Laurel, is the source of the spice Bay leaf. It was also the source of the Laurel wreath of ancient Greece. It is distributed across the Mediterranean region from Spain to Turkey.
- Laurus novocanariensis Rivas Mart., Lousã, Fern. Prieto, E.Díaz, J.C. Costa & C. Aguiar, syn. L. canariensis Webb & Berth. (an illegitime name). Formerly included in L.azorica, and also known as the same Portuguese names as L. azorica, is native to the laurisilva forests of Madeira Islands and Canary Islands, and also locally in Morocco.
Fossils dating from before the Pleistocene glaciations show that species of Laurus were formerly distributed more widely around the Mediterranean and North Africa, when the climate was more humid and mild than at present. It is currently thought that the drying of the Mediterranean basin during the glaciations caused Laurus to retreat to the mildest climate refuges, including southern Spain, Portugal and the Macaronesian islands. With the end of the last glacial period, L. nobilis recovered some of its former range around the Mediterranean.
A recent study found that native stands classified as L. nobilis in northern Spain shared greater genetic and morphological similarity to L. azorica than to populations of L. nobilis native to rest of Spain, France and Italy [Arroyo-Garcia et al. 2001]. This populations like the Cortegada Island population, in Galicia, famous for its large grove of laurels, come from seeds dispersed by birds but is not indigenous to the island, as this islander forest originated spontaneously from laurel specimens that were planted after the original vegetation was destroyed.
Ecology
The genus was more distributed in the Tertiary than it is now.[citation needed] The extant laurel species of this group are relatively young.[citation needed]
The Laurus genus features have been used to name many botanical species that have similar foliage to Laurus due to convergent evolution. Laurophyll or lauroid leaves are characterized by a generous layer of wax, making them glossy in appearance, and narrow, pointed oval in shape with an apical mucro, or 'drip tip', which permit the leaves to shed water despite the humidity, allowing transpiration from plant. The scientific names laurina, laurifolia, laurophylla, lauriformis, and lauroides are often used to name species of other plant families that resemble the Laurus genus and the Lauraceae family.[1] Furthermore, it is common that the dispersal of seeds in many laurel forest species is due to birds that swallow them, so the fruit are often similar to attract birds. The three laurel species in the genus Laurus are dispersed by birds columbiform, mainly.[citation needed]
References
- Arroyo-García, R., Martínez-Zapater, J.M., Fernández Prieto, J.A., & Álvarez-Arbesú R. (2001). AFLP evaluation of genetic similarity among laurel populations. Euphytica 122 (1): 155-164.
- Barbero, M., Benabid, A., Peyre, C. & Quezel, P. (1981). Sur la presence au Maroc de Laurus azorica (Seub.) Franco. Anales Jard. Bot. Madrid 37 (2): 467-472. Available online (pdf file; in French).
- Costa, J. C., Capelo, J., Jardim, R., Sequeira, M., (2004). Catálogo Florístico do Arquipélago da Madeira. Quercetea 6, 187-200.
- Mabberley, D.J (1997). The Plant Book: a Portable Dictionary of the Vascular Plants. Second edition, pp. 393–394.