New records of pteridophytes from Annobón Island

Eight new records of pteridophytes are listed for the fl ora of Annobón (Equatorial Guinea). Specimen information is provided for 12 literature-based records in the Flora de Guinea Ecuatorial. An account of pteridophyte collecting on the island is provided. Pteridophyte diversity in Annobón is updated to 49 species. * South African National Biodiversity Institute, Private Bag X101, 0001 Pretoria. H.G.W.J. Schweickerdt Herbarium, Department of Botany, University of Pretoria, 0002 Pretoria. ** C.P. 289, São Tomé, São Tomé e Príncipe. *** Compton Herbarium, South African National Biodiversity Institute, Private Bag X7, 7735 Claremont, Cape Town. + Author for correspondence: email address: estrelafi gueiredo@hotmail.com MS. received: 2009-01-08. Bothalia 39,2: 213–216 (2009) 214 Bothalia 39,2 (2009) The British botanist Arthur Wallis Exell only made a visit of a few hours on 15 February 1933. However, Exell’s (1944) contribution to our knowledge of the island’s fl ora cannot be underestimated as his Catalogue of the vascular plants of S. Tomé (with Príncipe and Annobon) and his later additions to this work (Exell 1956, 1959; Exell & Rozeira 1958) have remained the most important botanical references on the Gulf of Guinea islands. In 1956, Rose and Denizot (fi rst names unrecorded) of the Muséum National d’Histoire Naturelle in Paris visited the island as part of a multidisciplinary team on board the research vessel the Calypso. It is unfortunate that their results have not been published and we were unable to study their collections for this work. The most signifi cant biological expedition since that of Mildbraed was made in 1959 by a joint Spanish-British expedition, which included the botanists Thomas Christopher Wrigley and Fenella Ann Melville (later Mrs Wrigley). They stayed on the island from July to August that year (Exell 1963). Although Exell (1963) studied some, but not all, of their spermatophyte specimens, their pteridophyte collections have never been studied until now. These collections are housed in the herbarium of the Natural History Museum, London (BM) but have never been incorporated into the main collection. They were determined in an unpublished list by J.A. Crabbe (1960). The botanist Bernard Descoings visited Annobón in 1964 and made several collections that are deposited at the Montpellier Herbarium (MPU). He arrived at Annobón by boat, from Pointe Noire, as part of an expedition with several researchers. During his stay on the island, which lasted from 24 February to 3 March 1964, he collected 233 numbers (12730–12963). Fifty-six of these collection numbers are pteridophytes and they were examined by the fi rst author at MPU. In 1987, a Spanish expedition including the botanist Manuel Fidalgo de Carvalho, fi nanced by Cooperacion Espanhola and led by the Associacion Amigos de Doñana, visited the island. The specimens collected are kept at Real Jardín Botánico (MA), Madrid. In October 2000, the second author visited the island for nine days as part of the multidisciplinary Annobón 2000 Expedition constituted of a British, Equatorial Guinean and Spanish team. Botanical collections were made by Crissantos Obama of the Equatorial Guinea National Herbarium and Angus Gascoigne; the pteridophyte specimens of the latter are housed in the Centro de Botânica (LISC) in Lisbon. LIST OF TAXA (+ = new record; ! = confi rmed record) ! Alsophila manniana (Hook.) R.M.Tryon ANNOBÓN: s.l., ± 500 m, 03-03-1964, Descoings 12958 (MPU); towards top of Surcado [Macizo Santa Mina], 1900 ft [579 m], forming a closed community of its own, 02-08-1959, Wrigley 226 (BM). Note: this species is apparently limited to the very top of Macizo Santa Mina, the highest peak on the island (695 m), as it was not observed on the second highest, Pico Quioveo (598 m). TABLE 1.—List of pteridophytes recorded on Annobón Island Taxon Notes Abrodictyum rigidum (Sw.) Ebihara & Dubuisson Literature-based Adiantum mettenii Kuhn Literature-based Alsophila manniana (Hook.) R.M.Tryon Confi rmed Arthropteris orientalis (J.F.Gmel.) Posth. Asplenium africanum Desv. Asplenium anisophyllum Kunze Asplenium annobonense Viane Asplenium nigritianum Hook. Asplenium sandersonii Hook. Asplenium variabile Hook. New record Blechnum attenuatum (Sw.) Mett. Confi rmed Christella dentata (Forssk.) Brownsey & Jermy Cochlidium serrulatum (Sw.) L.E.Bishop Confi rmed Crepidomanes africanum (H.Christ) Ebihara & Dubuisson Literature-based Crepidomanes melanotrichum (Schltdl.) J.P.Roux Confi rmed Crepidomanes mettenii (C.Chr.) Ebihara & Dubuisson Confi rmed Cyclosorus striatus (Schumach.) Ching New record Davallia chaerophylloides (Poir.) Steud. Confi rmed Dicranopteris linearis (Burm.f.) Underw. Didymoglossum erosum (Willd.) J.P.Roux Literature-based Diplazium proliferum (Lam.) Kaulf. Dryopteris aurantiaca J.P.Roux Huperzia ophioglossoides (Lam.) Rothm. Literature-based Hymenophyllum hirsutum (L.) Sw. Confi rmed Hymenophyllum kuhnii C.Chr. Lepisorus excavatus (Bory ex Willd.) Ching Loxogramme abyssinica (Baker) M.G.Price Lycopodiella cernua (L.) Pic.Serm. Marattia fraxinea Sm. Microgramma mauritiana (Willd.) Tardieu Microlepia speluncae (L.) T.Moore New record Microsorum punctatum (L.) Copel. Confi rmed Nephrolepis biserrata (Sw.) Schott Nephrolepis undulata (Afzel. ex Sw.) J.Sm. New record Oleandra annetii Tardieu New record Oleandra distenta Kunze Confi rmed Ophioglossum reticulatum L. Confi rmed Pellaea doniana J.Sm. ex Hook. Pityrogramma calomelanos (L.) Link Pneumatopteris oppositifolia (Hook.) Holttum Pneumatopteris venulosa (Kuntze) Holttum Confi rmed Psilotum nudum (L.) P.Beauv. Pteris linearis Poir. New record Pteris togoensis Hieron. Confi rmed Tectaria camerooniana (Hook.) Alston New record Tectaria fernandensis (Baker) C.Chr. Trichomanes crispiforme Alston Literature-based Vittaria guineensis Desv. Vittaria owariensis Fée New record Bothalia 39,2 (2009) 215 + Asplenium variabile Hook. ANNOBÓN: SW of Crater Lake [Lago A Pot], under forest, on fl oor, some below other ferns, 1500 ft [457 m], plantlets at tips of some leaves in shade, 29-07-1959, Melville 198 (BM). Distribution: Angola, Bioko, Cameroon, Central African Republic, Côte d’Ivoire, DRC, Equatorial Guinea, Gabon, Ghana, Guinea, Kenya, Liberia, Madagascar, Príncipe, São Tomé, Sierra Leone, Sudan, Tanzania, Uganda (Roux 2009). Note: J.A. Crabbe (1960) described this specimen as belonging to the Asplenium variabile complex and noted ‘the most decompound example I have seen; possibly warranting new specifi c rank’. ! Blechnum attenuatum (Sw.) Mett. ANNOBÓN: summit section of Macizo Santa Mina, above 500 m, 03-03-1964, Descoings 12954 (MPU). Note: Wrigley/Melville 268 cited in J.A. Crabbe’s list of specimens from the 1959 expedition (Crabbe 1960) is no longer in the same box as the other specimens. A handwritten note on the box states ‘Blechnum removed TCC 10/77’, referring to T.C. Chambers. The specimen could also not be found in the Natural History Museum Herbarium’s main Blechnum collection. ! Cochlidium serrulatum (Sw.) L.E.Bishop ANNOBÓN: summit section of Macizo Santa Mina, above 500 m, 03-03-1964, Descoings 12963 (MPU); Pico del Centro, (also on top of Surcado), epiphyte on 236, 2050 ft [625 m], small acrosticoid fern, grey-green colour, 05-08-1959, Wrigley 237 (BM). Note: Exell (1963) does not cite Wrigley 236 (on which 237 was an epiphyte) and the present authors have not located the specimen at BM. ! Crepidomanes melanotrichum (Schltdl.) J.P.Roux ANNOBÓN: Monte del Centro, W face, 400–600 m, 27-02-1964, Descoings 12879b (MPU). ! Crepidomanes mettenii (C.Chr.) Ebihara & Dubuisson ANNOBÓN: Monte del Centro, W face, 400–600 m, 27-02-1964, Descoings 12888 (MPU). + Cyclosorus striatus (Schumach.) Ching ANNOBÓN: round Crater Lake, marshy ground extending into the water, 885 ft [270 m], Wrigley 279 (BM). Distribution: Bioko, Burundi, DRC, Equatorial Guinea, GuineaBissau, Liberia, Rwanda, Sierra Leone, Sudan (Roux 2009). ! Davallia chaerophylloides (Poir.) Steud. ANNOBÓN: path from San Antonio del Norte [Palé] to the Crater Lake [Lago A Pot], 100–200 m alt., 25-02-1964, Descoings 12830 (MPU); near the Crater Lake [Lago A Pot], ± 280 m, epiphyte in woodland, Exell 896 (BM); on path from Anganchi (S. Pedro) to Cus, 50 m, 22-10-2000, observed from 50–480 m in the Anganchi Valley, very common, Gascoigne 60 (LISC); NE side of Pico de Fogo, rocky places, just fertile, (rare), 24-07-1959, Melville 185 (BM). Note: in the main entry for Davallia denticulata (Burm.f.) Underw. (= D. chaerophylloides) in Velayos et al. (2008: 41) there is only a literature record for Annobón. However, Gascoigne 60 was listed in the index to collections, referring to this species (Velayos et al. 2008: 149). ! Hymenophyllum hirsutum (L.) Sw. ANNOBÓN: Monte del Centro, W face, 400–600 m, 27-02-1964, Descoings 12879a (MPU); summit section of Macizo Santa Mina, above 500 m, 03-03-1964, Descoings 12957b (MPU). + Microlepia speluncae (L.) T.Moore ANNOBÓN: Pico Santiago, W of the Crater Lake [Lago A Pot], 200–320 m, 26-02-1964, Descoings 12866 (MPU); S shore of Crater Lake [Lago A Pot], under Elaeis, 885 ft [270 m], fertile, 2 × pinnate pinnatifi d, 31-07-1959, Wrigley 225 (BM). Distribution: Angola, Bioko, Botswana, Burundi, Cameroon, Central African Republic, Comoro Is., Congo, Côte d’Ivoire, DRC, Equatorial Guinea, Ethiopia, Gabon, Ghana, Guinea, Kenya, Liberia, Madagascar, Malawi, Mozambique, Namibia, Nigeria, Réunion, Rwanda, São Tomé, Seychelles, Sierra Leone, South Africa, Sudan, Swaziland, Tanzania, Togo, Uganda, Zambia, Zimbabwe (Roux 2009). ! Microsorum punctatum (L.) Copel. ANNOBÓN: around San Antonio del Norte [Palé], 24-02-1964, Descoings 12790 (MPU); path from San Antonio del Norte [Palé] to the Crater Lake [Lago A Pot], 100–200 m, 25-02-1964, Descoings 12813 (MPU); SW of Crater Lake, on rocks beneath forest and epiphytic on trees, quite commonly, 1500 ft [457 m], more common than [Melville] 202 [Asplenium africanum], f


INTRODUCTION
The pteridophytes of Equatorial Guinea were recently revised for the Flora de Guinea Ecuatorial (Velayos et al. 2008).In the introduction of that work, 36 species (Velayos et al. 2008: xi) are recorded for the island of Annobón (Gulf of Guinea).However, in the text of the Flora, 41 species are recorded as present in Annobón, 23 of these being specimen-based and 18 based on literature citations.These fi gures differ from our own unpublished data on the pteridophytes of that island.Our data were compiled on our previous research on the pteridophyte fl ora of the islands in the Gulf of Guinea (Figueiredo 1998(Figueiredo , 2000(Figueiredo , 2001(Figueiredo , 2002;;Figueiredo & Gascoigne 2001) and after the second author participated in the Annobón 2000 Expedition when several more collections of these plants were made.A comparison of both data sets revealed additional records and confi rmed records that lacked specimen citation (Table 1) in Velayos et al. (2008).

MATERIAL AND METHODS
Two little-known collection sets from Annobón were examined during this work: the collections of Bernard Descoings, kept at the Université de Montpellier (MPU) (examined by the fi rst author) and the Melville/Wrigley collection, kept at the Natural History Museum (BM) in London (examined by the second author).We also had access to an unpublished list of the Melville/Wrigley collections determined by J.A. Crabbe.These collections were not examined by Velayos et al. (2008) for the Flora de Guinea Ecuatorial.
In this paper we list eight new records for the fl ora of Annobón and provide specimen information for 12 of 18 literature-based records in Velayos et al. (2008), bringing the number of pteridophytes currently known for the island to 49 species (Table 1).The nomenclature follows Roux (2009).Forty collections are cited.The list of new records and confi rmed occurrences is given in alphabetical order.The names of the actual localities (Instituto Geográfi co Nacional de España 1982) are given in square brackets.An account of botanical collecting on the island is presented.Herbarium acronyms follow Holm gren & Holmgren (1998).

COLLECTORS ON ANNOBÓN
The island of Annobón is situated in the Gulf of Guinea, ± 400 km from Gabon.It has a surface area of only 17 km 2 .Due to the remoteness of the island, it is rarely visited and botanical exploration on Annobón has thus been limited when compared with the other Gulf of Guinea islands (Bioko, Príncipe and São Tomé).Exell (1944) gives an account of the fi rst plant collections made on the island by Andrew B. Curror who visited it some time between 1839 and 1842 but only collected two specimens of fl owering plants.Between 1861 and 1864, Richard Burton, then the British Consul in Bioko, collected on the island but again neglected the pteridophytes.
The fi rst collections of ferns were made by the Portuguese explorer Francisco Newton who spent three months on the island from November 1892 to January 1893.Newton was employed as an offi cial collector of the Portuguese government and was the fi rst to collect much of the fauna of Principe, São Tomé and Annobón but his botanical collections are of less importance (Sobrinho 1953).Six fern species were collected by Newton: Adiantum mettenii, Asplenium africanum, Dicranopteris linearis, Microgramma mauritiana, Ophioglossum reticulatum and Pellaea doniana.Newton's collections were deposited at the University of Lisbon Herbarium (LISU) and treated by Sobrinho (1953).Newton returned to Annobón later in 1893, but this visit lasted no more than one day and he was unable to make any further collections.
The most important botanical collections were made by Gottfried Wilhem Johannes Mildbraed who spent over a month on the island from 5 September to 13 October 1911 at the end of the Duke of Mecklenburg's second German Central Africa Expedition.Mildbraed collected 32 pteridophyte species, and made detailed notes on the island's vegetation (Exell 1944).Alston (1944) examined some of Mildbraed's collections.Bothalia 39,2 (2009) The British botanist Arthur Wallis Exell only made a visit of a few hours on 15 February 1933.However, Exell's (1944) contribution to our knowledge of the island's fl ora cannot be underestimated as his Catalogue of the vascular plants of S. Tomé (with Príncipe and Annobon) and his later additions to this work (Exell 1956(Exell , 1959;;Exell & Rozeira 1958) have remained the most important botanical references on the Gulf of Guinea islands.
In 1956, Rose and Denizot (fi rst names unrecorded) of the Muséum National d'Histoire Naturelle in Paris visited the island as part of a multidisciplinary team on board the research vessel the Calypso.It is unfortunate that their results have not been published and we were unable to study their collections for this work.
The most signifi cant biological expedition since that of Mildbraed was made in 1959 by a joint Spanish-British expedition, which included the botanists Thomas Christopher Wrigley and Fenella Ann Melville (later Mrs Wrigley).They stayed on the island from July to August that year (Exell 1963).Although Exell (1963) studied some, but not all, of their spermatophyte specimens, their pteridophyte collections have never been studied until now.These collections are housed in the herbarium of the Natural History Museum, London (BM) but have never been incorporated into the main collection.They were determined in an unpublished list by J.A. Crabbe (1960).
The botanist Bernard Descoings visited Annobón in 1964 and made several collections that are deposited at the Montpellier Herbarium (MPU).He arrived at Annobón by boat, from Pointe Noire, as part of an expedition with several researchers.During his stay on the island, which lasted from 24 February to 3 March 1964, he collected 233 numbers (12730-12963).Fifty-six of these collection numbers are pteridophytes and they were examined by the fi rst author at MPU.
In 1987, a Spanish expedition including the botanist Manuel Fidalgo de Carvalho, fi nanced by Cooperacion Espanhola and led by the Associacion Amigos de Doñana, visited the island.The specimens collected are kept at Real Jardín Botánico (MA), Madrid.
In October 2000, the second author visited the island for nine days as part of the multidisciplinary Annobón 2000 Expedition constituted of a British, Equatorial Guinean and Spanish team.Botanical collections were made by Crissantos Obama of the Equatorial Guinea National Herbarium and Angus Gascoigne; the pteridophyte specimens of the latter are housed in the Centro de Botânica (LISC) in Lisbon.Note: this species is apparently limited to the very top of Macizo Santa Mina, the highest peak on the island (695 m), as it was not observed on the second highest, Pico Quioveo (598 m).Distribution: Angola, Bioko, Cameroon, Central African Republic, Côte d'Ivoire, DRC, Equatorial Guinea, Gabon, Ghana, Guinea, Kenya, Liberia, Madagascar, Príncipe, São Tomé, Sierra Leone, Sudan, Tanzania, Uganda (Roux 2009).Note: J.A. Crabbe (1960) described this specimen as belonging to the Asplenium variabile complex and noted 'the most decompound example I have seen; possibly warranting new specifi c rank'.
Note: the maximum altitude of Monte Santiago, over which the path to Quioveo passes, is 257 m.This is the fi rst record for Equatorial Guinea.Velayos et al. (2008: 123) excluded this species for lack of specimens.
Additionally, the occurrence of the genus Adiantum on Annobón can be confi rmed.The collection Newton s.n.(LISU) was cited in the literature (Sobrinho 1953) as Adiantum mettenii Kuhn but Velayos et al. (2008) report it as not located at LISU.During the Annobón 2000 Expedition, a species of Adiantum was encountered and photographed in the Anganchi Valley at S1°26.368' E5°38.649' at approximately 70 m.The photograph does not show suffi cient detail to allow positive identifi cation at species level but confi rms the presence of the genus on Annobón.