INTRODUCTION
⌅Marattiaceae Kaulf. is a family of eusporangiate ferns that inhabit the tropics of both hemispheres (Moran, 2017Moran RC. 2017. American Genera of Ferns and Lycophytes a guide for students. NYBG Press, NY.). This family comprises six genera (Danaea Sm., Eupodium J.Sm., Marattia Sw., Angiopteris Hoffm., Christensenia Maxon and Ptisana Murdock) and about 111 species (Murdock, 2008aMurdock AG. 2008a. Phylogeny of marattioid ferns (Marattiaceae): inferring a root in the absence of a closely related outgroup. American Journal of Botany. 95: 626–641.; PPG, 2016PPG I [Pteridophyte Phylogeny Group I]. 2016. A community-derived classification for extant lycophytes and ferns. Journal of Systematics and Evolution. 54: 563-603.). It is considered a monophyletic group (Pryer et al., 2004Pryer KM, Schuettpelz E, Wolf PG, Schneider H, Smith AR, Cranfill R. 2004. Phylogeny and evolution of ferns (monilophytes) with a focus on the early leptosporangiate divergences. American Journal of Botany. 91: 1582-1598.) readily distinguishable by the pulvinus-like swellings on the leaf axes (nodes), ear-like stipules at the stem-leaf junction, and sporangia opening by a terminal pore or slit (Moran, 2017Moran RC. 2017. American Genera of Ferns and Lycophytes a guide for students. NYBG Press, NY.).
Several authors have studied the taxonomy of Angiopteris (de Vriese and Harting, 1853De Vriese WH de, Harting P. 1853. Monographie des Marattiacées. Noothoven van Goor, Leiden and Arnz, Düsseldorf.; Hooker and Baker, 1868Hooker WJ, Baker JG. 1868. Synopsis filicum; or, A synopsis of all known ferns, including the Osmundaceae, Schizaesveae, Marattiaceae, and Ophioglossaceae (chiefly derived from the Kew herbarium). R. Hardwicke, London.; Hieronymus, 1919Hieronymus G. 1919. Bemerkungen zur Kenntniss der Gattung Angiopteris Hoffm. nebst Beschreibungen neuer Arten und Varietiten derselben. Hedwigia. 61: 242-285.; Holttum, 1978Holttum RE. 1978. The morphology and taxonomy of Angiopteris (Marattiaceae) with description of a new species. Kew Bulletin. 32: 587-594.; Rolleri, 2002Rolleri CH. 2002. Caracteres diagnósticos y taxonomía del género Angiopteris Hoffm. (Marattiaceae) I, Los caracteres. Revista del Museo La Plata, Botánica. 15: 39-47.; Zhaorong and Christenhusz, 2013Zhaorong H, Christenhusz M. 2013. Marattiaceae. In: Zhengui W, Raven PH, Denyuan H. (eds.), Flora of China, Vol. 2–3 (Pteridophytes), 82-89, Missouri Botanical Garden Press, Missouri.). This genus can be distinguished by the presence of monomorphic leaves, strongly swollen petiole bases, blades usually pinnately compound, sporangia opening by slits (fused basally into sori, but free apically) and false veins often prominent on the pinnules (Murdock, 2008bMurdock AG. 2008b. A taxonomic revision of the eusporangiate fern family Marattiaceae, with description of a new genus Ptisana. Taxon. 57: 737-755.). According to PPGI (2016)PPG I [Pteridophyte Phylogeny Group I]. 2016. A community-derived classification for extant lycophytes and ferns. Journal of Systematics and Evolution. 54: 563-603., species delimitation of Angiopteris varies widely; there may be 10 to 30 species worldwide. The genus has been recorded from Madagascar, India, Sri-Lanka, Nepal, Tailandia, Myanmar (Birmania), Malaysia, China, Indonesia, Melanesia, Micronesia, Polinesia and Hawaii (Zhaorong and Christenhusz, 2013Zhaorong H, Christenhusz M. 2013. Marattiaceae. In: Zhengui W, Raven PH, Denyuan H. (eds.), Flora of China, Vol. 2–3 (Pteridophytes), 82-89, Missouri Botanical Garden Press, Missouri.).
The Oriental vessel fern, Angiopteris evecta is native to the South Pacific, but has been introduced into other localities since the 18th century, and is now listed as an invasive species in several regions (Costa Rica, Jamaica and Hawái) (Christenhusz and Toivonen, 2008Christenhusz MJM, Toivonen TK. 2008. Giants invading the tropics: The oriental vessel fern, Angiopteris evecta (Marattiaceae). Biological Invasions. 10: 1215-1228.). Proctor (1985)Proctor GR. 1985. Ferns of Jamaica. British Museum (Nat. Hist.), London. indicated that it is naturalized in Jamaica, after escaping from cultivation in botanical gardens. A. evecta was first recorded in Cuba by Caluff and Shelton (2009-2010)Caluff MG, Shelton M. 2009-2010. Angiopteris evecta (Marattiaceae, Pteridophyta), nuevo registro para la pteridoflora cubana. Revista Jardín Botánico Nacional. 30-31: 247-249. from the Sierra Maestra Mountain range. It is also found in cultivation in the National Botanical Garden of Cuba (López-García and Sánchez, 2021López-García AG, Sánchez C. 2021. Helechos de las colecciones de plantas vivas del Jardín Botánico Nacional de Cuba. Revista Jardín Botánico Nacional. 42: 243-253.) and in the Ferns Garden of Santiago de Cuba (Caluff and Shelton, 2009-2010Caluff MG, Shelton M. 2009-2010. Angiopteris evecta (Marattiaceae, Pteridophyta), nuevo registro para la pteridoflora cubana. Revista Jardín Botánico Nacional. 30-31: 247-249.). Oviedo et al. (2012) and Oviedo and González-Oliva (2015) have included it as a potential invasive species due to its high dispersal capacity. We intend to update the description and distribution of A. evecta due to the invasive behavior of allochthonous populations of this species in other regions of the Caribbean and Paleotropics.
MATERIALS AND METHODS
⌅The description of A. evecta was based on two herbarium specimens from the HAJB (Acronyms according to Thiers 2024Thiers, B. 2024. Index Herbariorum: A global directory of public herbaria and associated staff. New York Botanical Garden’s Virtual Herbarium. https://sweetgum.nybg.org/science/ih/.), from which the stem and leaf characters were measured (Table 1). These characters were compared with three digital images of Jamaican collections (from https://www.gbif.org/) and with other descriptions (Proctor, 1985Proctor GR. 1985. Ferns of Jamaica. British Museum (Nat. Hist.), London.; Rolleri, 2002Rolleri CH. 2002. Caracteres diagnósticos y taxonomía del género Angiopteris Hoffm. (Marattiaceae) I, Los caracteres. Revista del Museo La Plata, Botánica. 15: 39-47.; Murdock, 2008aMurdock AG. 2008a. Phylogeny of marattioid ferns (Marattiaceae): inferring a root in the absence of a closely related outgroup. American Journal of Botany. 95: 626–641.) (Appendix 1). In addition, distribution maps of the species were generated using Google Maps and ArcGIS v.10.2 (ESRI, 2013ESRI 2013. ARCMAP. ArcGIS. 10.2. Environmental Systems Research Institute, Redlands, California.), based on the localities annotated in the herbarium labels.
| Quantitative Characters | Qualitative Characters | |
|---|---|---|
| Stem | ||
| Leaves | ||
| Stipes | ||
| Blades | ||
| Pinnae and pinnules | ||
| Sporangia |
RESULTS AND DISCUSSION
⌅Angiopteris evecta (G.Forst.) Hoffm. Commentat. Soc. Regiae Sci. Gott. 12: 29. 1794. ≡Polypodium evectum G. Forst. Fl. Ins. Austr. 81. 1786. ≡ Danaea evecta (G.Forst.) Spreng. in J. Bot. (Schrader) (2): 272. 1799.
Description
⌅Terrestrial plant. Erect and massive stem, 50-80 cm long. and equal width, partly covered by dead leaves and adult leaves stipules, basifixed or peltate scales 5-7 × 1 mm (or less), linear, brown, entire margin, truncate base, filiform apex. Monomorphic leaves, fasciculate, 2-pinnate, 2-6 m; stipules 4.88-6.8 × 5.8-6.45 cm, orbicular, green, fleshy, sinuous to entire margin; stipes 69.7-195 cm long., 3.28-4.8 cm diameter, shorter than the blades, with one node at the base, when young, bearing basifixed and linear scales, 3.1-5 × 1 mm (or less), brown to golden, truncated or rounded at base, filiform apex, deciduous; blades 61.3-147.13 × 92-205 cm, ovate, hastate base, evenly pinnate, with up to 45 pairs of pinnae; rachis with indument similar to that of the stipes; pinnae petiolulate, petiolule with one node at the base, 2.6-5.1 cm long., 54.8-92.7 × 22-31.62 cm, oblong-oblanceolate, truncate at base, sagittate at apex, evenly pinnate, 30-36 pairs of pinnules; costa adaxially grooved and abaxially terete, indument similar to that of the stipes; pinnules, petiolulate, 2-4 mm, glabrous, 3.5-10 × 0.8-2.4 cm, 2.5 to 3 cm from each other, linear to oblong, asymmetric at base, acuminate-attenuate at apex, crenate at margins but serrate towards the apex; pinnate venation, with simple or forked veins, with a false veinlet between lateral veins extending from the costule to the margin, abaxial surface with indument similar to that of the stipes; sporangia grouped in sori, ellipsoid sori on the distal end of lateral veins, each sori with 7-16 sporangia, opening by a slit (Fig. 1, 2).
Distribution in Cuba
⌅Eastern Cuba: Santiago de Cuba (Gran Piedra) and Guantánamo (near Yunque de Baracoa). Grows in montane rain forest from 250 to 600 m above sea level (Fig. 3). The species was recorded in the Guantánamo province for the first time. It was located 1 km east of Tabajó del Toa and 1.5 km north of Yunque de Baracoa, in the 20 21̕ 20.6” N and 74 34̓ 43.4” W. Only one individual was found growing on a slope that descends towards Tabajó del Toa, sloping towards the west and forming a slope that rises to 450 m. The altitude was about 250 m. This area corresponded to the rainforest ecosystem that has been cleared for the cultivation of coffee and banana plantations, among other crops. Currently, it is covered by some trees such as Artocarpus altilis (Parkinson) Fosberg (bread tree), Cecropia schreberiana Miq., ferns of the genus Cyathea Sm., shrubs of the genus Piper L. and lianas such as Trichostigma octandrum (L.) H. Walter (“guaniquí”).
The potential range of distribution of A. evecta was modelled by Christenhusz and Toivonen (2008)Christenhusz MJM, Toivonen TK. 2008. Giants invading the tropics: The oriental vessel fern, Angiopteris evecta (Marattiaceae). Biological Invasions. 10: 1215-1228.. The models predicted that the species could spread across the more humid parts of tropical America, Africa and Asia, and towards coastal habitats in the Caribbean, Central America and Hawaii. In any case, the species has to be introduced into these areas, just as it is in Cuba. It is considered that this fern arrived for the first time in the country via a traveling spore from a Jamaican individual (Caluff and Shelton, 2009-2010Caluff MG, Shelton M. 2009-2010. Angiopteris evecta (Marattiaceae, Pteridophyta), nuevo registro para la pteridoflora cubana. Revista Jardín Botánico Nacional. 30-31: 247-249.).
The discovery of a new adult individual of A. evecta raises the question of how the dispersal of the species is taken place in Cuba. It is important to note that this plant has both vegetative and sexual reproduction. Vegetative propagation occurs through fleshy stipules, which have proliferous buds that can grow into new plants when the stipules detach and find suitable soil (Hoshizaki and Moran, 2001Hoshizaki BJ, Moran RC. 2001. Fern grower’s manual. Timber Press, Portland.), although the stipules cannot travel long distances. When adults, the leaves produce thousands of sporangia, the spores of which can be wind-dispersed over 3 200 km (Tryon, 1979Tryon RM. 1979. Biogeography of the Antillean Fern Flora. In: Braunwell, D. (ed.), Plants and Islands, 55-68, Academic Press, London.). It is therefore plausible that the individual from the Yunque de Baracoa was the product of a germinated spore, but A. evecta takes many years before producing spores (Caluff and Shelton, 2009-2010Caluff MG, Shelton M. 2009-2010. Angiopteris evecta (Marattiaceae, Pteridophyta), nuevo registro para la pteridoflora cubana. Revista Jardín Botánico Nacional. 30-31: 247-249.).
According to Caluff and Shelton (2009 -2010)Caluff MG, Shelton M. 2009-2010. Angiopteris evecta (Marattiaceae, Pteridophyta), nuevo registro para la pteridoflora cubana. Revista Jardín Botánico Nacional. 30-31: 247-249., a seedling of this fern takes eight to ten years to develop into an adult plant, and a spore germinates in about two years and six months. The individuals located at Gran Piedra were adults in 2008. Given the approximate ages of the specimens recorded in Cuba and the distances between them, it is likely that the progenitor of the individual from Yunque de Baracoa is located in Gran Piedra (Santiago de Cuba). However, we cannot rule out the possibility that the new record from Yunque de Baracoa could be from a spore of a Jamaican individual.
On the other hand, the reproduction of A. evecta could lead to the formation of dense stands and therefore disturb natural ecosystems by competing with native species for space and light availability (Wilson, 1996Wilson KA. 1996. Alien ferns in Hawai’i. Pacific Science. 50:127-141.). In Cuba, this fern represents a transformer plant according to Oviedo et al. (2012) and Oviedo and González-Oliva (2015). However, in the two Cuban localities where the taxon has been recorded so far in the wild, its proliferation is rather slow, with only a few individuals recorded in Gran Piedra (Santiago de Cuba) and only one in Yunque de Baracoa (Guantánamo). The species is a long-lived plant and its invasion, after introduction, will be slow because of slow rates of growth and reproduction (Christenhusz and Toivonen, 2008Christenhusz MJM, Toivonen TK. 2008. Giants invading the tropics: The oriental vessel fern, Angiopteris evecta (Marattiaceae). Biological Invasions. 10: 1215-1228.). Once adults are established, the invasion is difficult to stop (Funk, 1987Funk E. 1987. Spontaneous spread of Angiopteris evecta (Marattiales) in the central Ko'olau Mountains, O'ahu, Hawai'i. Newsletter of the Hawaiian Botanical Society. 26: 58, 59.). For example, it was introduced for cultivation in the Mānoa Valley, in 1927 by H. L. Lyon (Wilson, 1996Wilson KA. 1996. Alien ferns in Hawai’i. Pacific Science. 50:127-141.) and rapidly spreaded (in about 40 years) to other regions of Hawaii. In terms of conservation, it will be crucial to develop a strategy for managing natural and cultivated populations of A. evecta in Cuba.
CONCLUSIONS
⌅This work provides a new source of information about the morphology and distribution of A. evecta in Cuba, with a new record of its occurrence. At present, it is not considered to be a threat to the natural populations of other plants in the country, given its small population. However, it is a potential short-term invader to the native flora of the Cuban montane rainforests. It is therefore necessary to emphasize its inclusion in the management strategies for the localities where it has been detected, in order to prevent its future spread.