Adiantum viscosum A. Cádiz-Véliz & A.E. Villarroel, 2023

Cádiz-Véliz, Arón, Palma-Villalobos, Bárbara, Villarroel, Alejandro E. & Muñoz-Schick, Mélica, 2023, Adiantum viscosum (Pteridaceae), a new species endemic to sclerophyllous forest of Central Chile, Phytotaxa 599 (3), pp. 183-192 : 185-189

Adiantum viscosum A. Cádiz-Véliz & A.E. Villarroel , sp. nov. ( Fig. 2 , 3 )

Diagnosis: — Adiantum viscosum differs from A. gertrudis and A. glanduliferum by the presence of capitate and glandular trichomes covering the entire aerial part of the plant, including pinnules, rachis, petioles and petiolules, which produce a sticky and aromatic resin.

Type:— CHILE. Valparaíso Region: San Felipe de Aconcagua Province, Putaendo, Cordón del Tabaco, Quebrada de Granallas , 32°36’39.41” S; 70°46’44.72” W, 1330 m elevation, 10 October 2021, A . Cádiz-Véliz & B. Palma-Villalobos 801 (holotype: JBN!; isotypes: SGO!, CONC!) .

Description:— Terrestrial and saxicolous herb. Rhizomes short and creeping, 2–4 mm in diam. Rhizome scales lanceolate, emarginate, 1.5–2.0 mm long, brown with entire margins, not ciliate. Fronds 12–27 cm long. Petioles 1–1.5 mm diam., 4–13 cm long, covered with lanceolate scales 1.5–2.5 mm, brown, grouped at the base. Blades 2–pinnate, rarely 3–pinnate, 9–15 × 6–9 cm, deltoid in outline, approximately half the length of the frond. Rachises straight. Petiolules 1–5 mm long. Pinnules 8–15 × 8–25 mm, flabellate to reniform in outline, base cuneate-symmetrical or asymmetrical, alternate, terminal pinnae usually larger than underlying ones, margin of sterile pinnules crenulateserrate, margin of fertile pinnules folded towards the underside, forming a false indusium. Veins dichotomous, terminating between the crenulate margins. Trichomes on the aerial parts of the plants, (including pinnules, rachis, petioles and petiolules) dense, capitate, glandular, 0.4–0.6 mm, 3–4 cellular, yellowish, hyaline, exuding a sticky and aromatic resin. False indusia 5–15 per pinnule, rectangular or reniform, with a depressed and hyaline basal margin. Spores not observed.

Etymology:— The specific epithet refers to the viscous resin produced by the glandular trichomes.

Distribution and habitat:— Currently, the only known locality of the species is the one reported in this manuscript, and corresponds to a southwest-exposed slope in the Quebrada de Granallas ( Fig. 1 ), where it occupies an area <100 m 2, at 1330 m elevation. The species inhabits rock crevices ( Fig. 3A ), within the vegetation belt Andean Mediterranean sclerophyllous forest of Quillaja saponaria Molina (1782: 354) and Lithraea caustica Hooker & Arnott (1833: 175) ( Luebert & Pliscoff 2017). Adiantum viscosum grows accompanied by Tropaeolum azureum Colla in Bertero (1832: 147), Colliguaja odorifera Molina (1782: 354) , Porlieria chilensis , and Kageneckia oblonga Ruiz & Pavón (1798b: 289) .

Phenology:— Adiantum viscosum initiates the formation of its fronds in mid-winter, after the first rains (June– July). The aerial part dies during the dry and warm summer (December–March).

Conservation status:— Using IUCN criteria (2012), Adiantum viscosum is proposed as Critically Endangered (CR) B1+B2ab (i,ii,iii), because the extent of occurrence (EOO) is <0.1 km 2, the area of occupancy (AOO) is <0.1 km 2, it is found in a single locality, and a decrease in EOO, AOO and habitat quality due to climate change effects is inferred ( Luebert & Pliscoff 2012, Pliscoff et al. 2012). In addition, the Cordón del Tabaco is threatened by mining projects, overgrazing, burning, drought, and unregulated tourism, which could affect the species ( Madrid et al. 2018, Cádiz-Véliz & Aliaga-Reyes 2019). Adiantum viscosum is not present in any area of the Sistema Nacional de Áreas Silvestres Protegidas del Estado (SNASPE).

Additional specimens examined:

Adiantum gertrudis — CHILE. Región de Valparaíso, Provincia de Limache: cerro La Campana, 28 April 1968, C. Villagrán s.n. ( SGO 86094); cerro La Campana, 28 October 1968, C. Villagrán s.n. ( SGO 83853); cerro La Campana, 1200 m, 28 April 1968, C. Villagrán & A. Mesa s.n. ( CONC 33060); cerro La Campana, 1350 m, 24 May 1936, A. Garaventa 3106 ( CONC 51092); cerro La Campana, 1300 m, 17 January 1937, A. Garaventa 3250 ( CONC 51091); cerro La Campana, 1500 m, 10 December 1938, A. Garaventa 6512 ( CONC 51101); cerro La Campana, 1300 m, February 1958, P. Valenzuela 49316 ( CONC 97032); cerro La Campana, 1500 m, December 1950, B. Collantes 21702 ( CONC 97033); cerro Las Vizcachas, 1300 m, 24 January 1961, C. Behn 4326 ( CONC 50160); Provincia de Valparaíso: Quebrada Verde, 2 October 1966, W. Sielfeld s.n ( SGO 118182); Jardín Botánico Nacional, 110 m, 2 October 1976, A. Guajardo s.n. ( CONC 150685); cuesta Balmaceda Fundo Los Perales, 300 m, 33º6’29.11’’S, 71º37’31’’O, 15 October 2015, S. Teillier & J. Macaya, 8485 ( CONC 186661).

Adiantum glanduliferum — CHILE. Región de Antofagasta, Provincia de Antofagasta: quebrada de Miguel Díaz, Punta Miguel Díaz, 400 m, 12 October 1941, E. Pisano & R. Bravo 450 ( SGO 102164); quebrada del Rincón, Rinconada de Paposo, 250 m, 24º56’S, 70º29’O, 02 December 1989, O. Gálvez, A. Cornejo & M. Villarroel 48 ( SGO 127410); Taltal, 20 m, 25º24’S, 70º29’O, 26 September 1940, S. Simpfendorfer s.n. ( CONC 97133); Quebrada de San Miguel Rinconada de Paposo, 350 m, 24º58’S, 70º28’O, 4 December 1988, A. Hoffmann 302 ( CONC 99049); Quebrada Matancilla, 500 m, 25º06’S, 70º27’O, 27 November 1997, M. Dillon & M. Villarroel 8121 ( CONC 150013). Región de Atacama, Provincia de Huasco: Mina Oriente, camino a Carrizal Bajo, 12 October 1992, M. Muñoz 3053 ( SGO 131464); Camino a Carrizal Bajo, km 44, 200 m, 28º09’S, 70º57’O, 26 October 1965, M. Ricardi, C. Marticorena & O. Matthei, 1527 ( CONC 33988); Huasco, 10 m, 28º28’S, 71º13’O, 15 August 1966, G. Montero 7570 ( CONC 63734). Región de Coquimbo, Provincia de Limarí: Fray Jorge, 7 October 1947, B. Sparre 2865 ( SGO 102105); Zorrilla, 400 m, 30º50’S, 71º30’O, 5 January 1948, C. Jiles 530 ( CONC 33978); Quebrada Toro, 330 m, 30º51’S, 71º18’O, 28 December 1950, C. Jiles 1924 ( CONC 33987); Monte Redondo, 400 m, 31º03’S, 71º35’O, 1 October 1947, C. Jiles 332 ( CONC 33990); Monte Redondo, 400 m, 31º03’S, 71º35’O, 17 November 1947, C. Jiles 492 ( CONC 102113), Fray Jorge, 450 m, 30º40’S, 71º40’O, September 1958, J. Kumerow s.n. ( CONC 39881), Provincia de Choapa: río Choapa, 750 m, 31º35’S, 71º32’O, February 1974, R. Torres s.n. ( CONC 97134); quebrada El Pangue, 14 km al norte de los Vilos, 120 m, 31º48’S, 71º30’O, 16 October 1971, C. Marticorena, R. Rodríguez & E. Weldt 1390 ( CONC 35767); 8 km al norte de Vilos, 30 m, 31º45’S, 71º31’O, 12 October 1963, C. Marticorena & O. Matthei 107 ( CONC 33966). Región de Valparaíso, Provincia de Petorca: Chincolco, November 1942, M. Espinosa s.n. ( SGO 81656); Zapallar, 11 October 1975, M. Valenzuela s.n. ( SGO 135226); Zapallar, November 1980, E. Barrera s.n. ( SGO 82908); Puente Guaquén, Carretera Panamericana, 30 m, 32º21’S, 71º27’O, 15 October 1971, C. Marticorena, R. Rodríguez & E. Weldt 1311 ( CONC 35765); Pichicuy, 5,20 m, 32º20’S, 71º28’O, 1 November 1974, C. Marticorena, O. Matthei & R. Rodríguez 203 ( CONC 43020); Petorca, 700 m, 32º15’S, 70º56’O, 16 September 1937, G. Montero 3156 ( CONC 63733); Provincia de San Felipe: Santuario Serranía El Ciprés, 1260 m, 32º40’40’’ S, 70º48’39’’O, 24 August 2013, A. Madrid & J. Larraín 14 ( CONC 186148); cerro de lo Vargas, 980 m, 32º40’S, 70º35’O, 17 February 1953, F. Torres s.n. ( CONC 38402); Provincia de Valparaíso: Dunas de Concón, 32º56’ S, 71º32’O, 01 October 2002, S. Elórtegui s.n. ( SGO 152627); Santuario de la Naturaleza Palmar El Salto, quebrada el Quiteño, 100 m, 33º03’S, 71º30’O, 01 October 2006, L. Flores & F. Aguirre s.n. ( SGO 155647); Loncura, 32º46’S, 7132’O, November 1953, H. Gunckel 27.368 ( CONC 96929); Quebrada Verde, 30 m, 33º02’S, 71º38’O, 24 August 1943, H. Schlegel 99 ( CONC 39901); Cuesta Zapata, 700 m, 33º23’S, 71 º15’O, 27 November 1971, C. Elgueta s.n. ( CONC 97045); Provincia de Marga-Marga: Limache, 130 m, 32º59’S, 71º15’O, September 1923, A. Garaventa 703 ( CONC 102965); Provincia de San Antonio: Mirasol Algarrobo, 50 m, 33º20’S, 71º39’O, 21 October 1961, C. Aste 38.257 ( CONC 96925); Algarrobo, 100 m, 33º21’S, 71º37’O, 2 November 1990, M. Baeza & P. Peñailillo s.n. ( CONC 113367). Región Metropolitana, Provincia de Cordillera: Termas de Colina, 15 October 1943, J. Guzmán s.n. ( SGO 081570); Provincia de Santiago: Quebrada de Peñalolén, 720 m, 33º28’S, 70º32’O, 10 December 1965, M. Mahu 2573 ( CONC 37835); Quebrada Agua del Palo cerro Manquehue, 750 m, 33º22’S, 70º35’O, 10 October 1960, P. Valenzuela 13 ( CONC 96924); Macul, 850 m, 33º30’S, 70º31’O, November 1954, A. Masena s.n. ( CONC 96928); El Arrayán, 1000 m, 33º21’S,70ª28’O, 27 September 1952, H. Gunckel 26.608 ( CONC 96953). Región de O’Higgins, Provincia del Cachapoal: Rancagua, 120 m, 32º22’S, 71º15’O, September 1926, C. Joseph s.n. ( CONC 96932); Región del Maule, Provincia de Curicó: costa norte de Llico, 19 November 1969, C. Villagrán s.n. ( SGO 85162); Querelema, Vichuquén, February 1923, E. Moore s.n. ( SGO 81614); 8 km al norte de Reserva Nacional Laguna Torca, 20 m, 34º42’S, 72º02’O, 13 December 2000, L. Finot & M. Leppe 89 ( CONC 150566); Provincia de Cauquenes: 10 m, 35º49’S, 72º35’O, January 1983, N. Toro s.n. ( CONC 96948). Región del Ñuble, Provincia del Ñuble: Camino de Trehuaco a Mela, 35 m, 36º25’S, 72º41’O, 28 November 2000, M. Baeza, P. López & M. Parra 1954 ( CONC 154386). Región del Bío-bío, Provincia del Biobío: Nacimiento, 70 m, 37º30’S, 72º40’O, E. Barros 517 ( CONC 96943).

Taxonomic relationships: —As mentioned above, Adiantum viscosum is morphologically similar to A. gertrudis and A. glanduliferum . However, A. poiretii Wikström f. bottini (Giudice & Nieto) Giudice (2016: 337) , which inhabits the Andes of Mendoza Province ( Argentina) also has glandular trichomes on the rachis, petiolules and the lower part of the pinnules ( Giudice 1999, Giudice 2016). Table 1 shows the morphological differences between those four species.

Figures

FIGURE 1. Distribution map of Adiatum viscosum: (A) Chile, in red the Valparaíso Region; (B) Valparaíso Region, the star indicates the location of A. viscosum, in blue the priority site for conservation Cerro Tabaco and in green the areas protected by the state (National Park, National Reserve and Natural Monument).

FIGURE 2. Illustration of Adiantum viscosum: (A) frond and rhizome; (B) petiole, detail of basal third; (C) rhizome scale; (D) sterile pinnules; (E) detail of the surface of a pinnule; (F) fertile pinnule; (G) detail of false indusium; (H) trichome. Illustrations based on A. Cádiz Véliz & B. Palma-Villalobos 801. Drawn by Arón Cádiz-Véliz.

FIGURE 3. Adiantum viscosum; (A) habit; (B) frond; (C) fertile frond; (D) detail of a fertile pinnule and false indusia; (E) detail of rachis covered with trichomes; (F–G) details of a pinnule covered with glandular and capitate trichomes; (H) detail of petiole and scales. Photographs:A. Cádiz-Véliz.