Pteris tremula (Polypodiopsida: Pteridaceae): A Naturalized Species in Argentina

Abstract

Pteris tremula (Polypodiopsida: Pteridaceae): A Naturalized Species in Argentina.—The cosmopolitan fern genus Pteris L. (subfamily Pteridoideae, Pteridaceae; PPG I, Journal of Systematics and Evolution 54:563–603. 2016), is one of the most diverse, including approximately 250 species that inhabit temperate, tropical, and subtropical regions of all continents from Australia, New Zealand, South Africa, and South America northward to Japan and North America. The species grow from open slopes to dense forests and from acid soils to limestone rock; about 60 taxa occur in the tropical Americas (Liao, Ding, Wu, Prado, and Gilbert, Flora of China 2–3:181–211. 2013., Chao, Rouhan, Amoroso, and Chiou, Annals of Botany 114:109–124. 2014). Some species, such as Pteris cretica L., P. longifolia L., P. multifida Poir., P. tremula R. Br., and P. vittata L. are reported as invasive plants in many parts of the world, being increasingly found in both, natural and urban areas in several countries possibly as a result of climate change and human migration. Some grow so prolifically that they have been classified as invasive weeds (Wilkins and Salter, Bulletin of the Royal Society of Chemistry:8–10. 2003, Robinson, Sheffield, and Sharpe, In Mehltreter, Walker, and Sharpe, Fern Ecology:255– 322. 2010). Among them, Pteris cretica, P. multifida and P. vittata are species that originated in Asia (China) or Europe and have been cited as naturalized in many regions of America since the early 1970s (e.g., de la Sota, Coleccion´ Cient´ıfica del Instituto Nacional de Tecnolog´ıa Agropecuaria 13:1–275. 1977; Prado and Windisch, Boletim do Instituto de Botanica Sa ˆ ˜o Paulo 13:103–199. 2000; Mazumdar and Arana, Phytotaxa 261:199–200. 2016). Pteris tremula belongs to the Pteris chilensis clade, characterized by three to four-pinnatifid lamina, ultimate pinnules (lobes) with veins free (Zhang, Rothfels, Ebihara, Schuettpelz, Le Pechon, Kamau, He, Zhou, Prado, Field, Yatskievych, Gao, ´ and Zhang, Cladistics 31:1–18. 2014). The clade contains only two species with disjunct distributions, the Chilean endemic Pteris chilensis Desv. and Pteris tremula, known as ‘‘tender brakefern’’ and originally distributed in the Australasian South Pacific, in Australia and Norfolk Island, Lord Howe Island, New Zealand, Kermadec Island, and Fiji (Kramer and Mc Carthy, Flora of Australia 48:242–248. 1998), often locally naturalized in the Northern Hemisphere (Zhang et al., 2014). Also, P. tremula has been cited as an invasive weed in South Africa (Baard and Kraaij, South African Journal of Botany 94:51–63. 2014).