Adetogramma chrysolepis (Hook.) T.E.Almeida, 2017

Almeida, Thais Elias, Salino, Alexandre, Dubuisson, Jean-Yves & Hennequin, Sabine, 2017, Adetogramma (Polypodiaceae), a new monotypic fern genus segregated from Polypodium, PhytoKeys 78, pp. 109-131 : 115-118

Adetogramma chrysolepis (Hook.) T.E.Almeida comb. nov. Figures 2 , 3 , 4

Lepicystis chrysolepis (Hook.) Diels, Nat. Pflanzenfam. 1(4): 322, f. 167A-B. 1899. Type: Based on Polypodium chrysolepis Hook.

Microgramma chrysolepis (Hook.) Crabbe, Brit. Fern Gaz. 9: 316. 1967. Type: Based on Polypodium chrysolepis Hook.

Polypodium bangii Baker, Bull. Misc. Inform. Kew 1901: 145. 1901. Type: Bolivia. Yungas, 1890, A.M. Bang 734 (lectotype, designated here: BM! [BM000936895]; isolectotypes: B! [B200075587], BR!, GH!, K! [K000590773], LE!, MO! [MO5472871)], NY! [NY00144786, NY00144787], US! [US00065725]).

Basionym.

Polypodium chrysolepis Hook., Icon. Pl. 8: t. 721. 1845.

Type.

Ecuador. Andes de Quito , W. Jameson 37 (wrongly typed in protologue as “73”; lectotype, designated by Tryon et al., 1993, pg. 151: K! [K000590772]; isolectotypes: BM! [BM000936896], G!, FI [ FI004543 !]) .

Plants epiphytic or epipetric, rarely terrestrial. Rhizomes long-creeping, branched, 0.6-0.9 mm wide, cylindrical, with four vascular bundles; short, perpendicular roots about 5-20 mm long, these regularly spaced, covered with brownish root hairs; rhizome scales 4.3-7.1 mm long, peltate, not clathrate, linear-lanceolate, with elongate cells, the margins entire from the base to the middle and toothed beyond the middle, with 1- or 2-celled marginal teeth, scales concolorous, stramineous and usually darker at the attachment point. Fronds remote, 2.2-4.5 mm apart, articulate, monomorphic. Stipes nearly absent to 55 mm long, 0.4-0.7 mm in diameter, covered with sparse peltate, lanceolate, sessile, non-clathrate, concolorous, stramineous scales, these 1.4-3.5 mm long, darker at the attachment point; phyllopodia darker than stipes. Laminae light green, 5.0-17.0 × 1.0- 2.5 cm, simple, chartaceous, linear-lanceate to lanceolate, bases acuminate to attenuate, decurrent in the distal third of the stipe, apices acute to obtuse, laminar surfaces squamose on both sides, scales lanceolate, peltate, sessile, non-clathrate, concolorous, translucent, stramineous, darker at attachment point, slightly erose at bases and entire at apices, scales present also on abaxial and adaxial sides of costae and veins, and on the laminar margins, 1.3-2.6 mm long. Veins free, immersed, obscure, 1-2 furcate, not reaching laminar margins, midribs and lateral veins immersed on both sides of the laminae, not evident. Sori superficial, rounded to oblong, 1.6-2.6 × 1.9-5.0 mm, terminal to subterminal on veins, receptacles elongate, sporangia long-stalked, paraphyses present, scale-like, similar those of the laminar surfaces, peltate, pedicellate, with pedicels as long as those of the sporangia, paraphyses completely covering immature sori. Spores yellow, with verrucate surfaces.

Distribution and ecology.

Restricted to central and southern Andes, with known collections from Ecuador, Peru, Bolivia, and Argentina (Fig. 5 ). It occurs preferably in high elevation formations, ranging from 1,800 to 4,100 meters above sea level, with most collections between 3,000-4,000 m in the central part of the Andes, but found at lower elevations further south in Southern Bolivia and Argentina. Adetogramma chrysolepis is mostly epiphytic or epipetric, rarely terrestrial. Epiphytic specimens usually grow on Polylepis , Berberis , or Buddleja , inside highland humid montane forests (Yungas). Epipetric ones were recorded as growing on rocks inside Yungas forest or in sub-alpine grasslands with scattered shrubs, normally associated with mosses ( de la Sota 1960). According to herbarium sheet labels, the species also occurs in secondary forests and modified areas.

Conservation status.

Least Concern (LC - IUCN 2016). Adetogramma chrysolepis presents EOO of 1,108,559.773 km2 and AOO of 5,300 km2, respectively, and its conservation status is considered Least Concern. However, the species occurs in a fragile environment that is undergoing an increasing pressure due to human settlement, and extensive grazing by cattle and camelids. Although it is known from at least 40 localities and occurs in several protected areas (e.g., Parque Nacional Carrasco, Cocha bamba, Bolivia; Reserva Nacional de Flora e Fauna de Tariquía, Tarija, Bolivia; Parque Nacional Huascarán, Ancash, Peru; Santuario Nacional de Ampay, Apurimac, Peru; Parque Nacional del Rio Abiseo, San Martín, Peru) no information on population fluctuations is available. Decline in the quality and area of occupancy in the near future seems feasible and it is advised that the species be monitored.

Etymology.

The generic epithet refers to the most distinctive character of the species, the free venation (Fig. 2C ); from the Greek adetos-, free and -gramma, line.

Notes.

Adetogramma is a monotypic genus, and although its sole species, A. chrysolepis , varies in laminar size and shape and stipe length, all other characters, such as the rhizome and stipe scales, venation, and paraphyses, are constant. Specimens from the Argentinean Provinces of Tucumán and Salta and Bolivian Provinces of Tarija and Chuquisaca have very long, linear laminae, and longer stipes, but in other characters are congruent with the circumscription here adopted for A. chrysolepis . This variation may reflect colonization of drier, seasonal habitats in a subtropical region.

Morphologically, Adetogramma chrysolepis shares features with several neotropical genera of Polypodiaceae (Table 2 ), while presenting unique characteristics within the group. Free veins (Figs 2C , 4C ) are shared with the Polypodium dulce species group, some Pecluma species, a few Pleopeltis species, few pinnatisected species of Serpocaulon , S. tayrona and most grammitids. Presence of peltate scales on the receptacle is shared between Adetogramma and Pleopeltis (Figs 2D-E , 3A , 4A-B ). In both genera, paraphyses may almost completely cover the sporangia in immature sori, and presumably have a protective function.

Kreier et al. (2008) hypothesized that Serpocaulon , sister group to Adetogramma , has the Bolivian Andes and adjacent southeastern Brazil as its ancestral area. According to this hypothesis, the Bolivian Andes formed a path for migration and successful colo nization of the Northern Andes, with subsequent migration into Central America and Caribbean regions. With Adetogramma as sister to Serpocaulon , we believe the hypothesis of the Bolivian Andes as putative ancestral area of the Adetogramma + Serpocaulon clade common ancestor to be more likely. From Bolivia, Adetogramma could have dispersed southwards where colder climate allowed it to colonize lower elevation habitats, and also migrated northwards to Peru and Ecuador. Adetogramma chrysolepis may represent a single relictual species from a previously more diverse and geographically widespread group, or a single, undiversified lineage that colonized high elevation environments. More detailed phylogenetic or phylogeographic studies are required to support or refute these hypotheses.

Specimens examined.

ARGENTINA. Jujuy: San Antonio, 27 Apr 2015, C. Martín 479 (SI); Valle Grande, 14 Apr 2016, C. Martín 730 (SI). Salta: Salta, 21 Nov 1945, S.A. Pieroffi 1326 (NY!); Santa Victoria, 05 Dec 2015, C. Martín 673 (SI). Tucumán: s.l., 1952, H. Brücher s.n. (LP!); s.l., s.d., L. Castillón 2248 (BM!); s.l., s.d., M. Lillo 11534 (BM!, GH!, K!, NY!); La Ventanita, s.d., M. Lillo 16713 (BM!, GH!, K!); Burruyacu, 20 Jan 1947, Borsini s.n. (LP!); Chicligasta, 11 Dec 1925, S. Venturi 4062 (BM!, GH!); idem, 13 Feb 1924, S. Venturi 3151 (GH!); Tafi del Vale, Jan 1912, L. Castillón 35 (BM!, GH!, K!, LP!, NY!). BOLIVIA. Chuquisaca: Hernando Siles, 09 Nov 2007, J. Villalobos 928 (MO!, UC). Cochabamba: Ayopaya, 07 May 1990, E. Hennipman 8148 (LPB!); idem, 28 Oct 2007, J. Terán 1486 (MO!); idem, 30 Oct 2007, J. Terán 1563 (MO!); Carrasco, 20 Mar 1991, I. Hensen 1819 (LPB!); idem, 25 Feb 1996, M. Mercado 501 (MO!); Chapare, 30 Sep 2001, J.R.I. Wood 17271 (LPB!); Cochabamba, 27 Jan 1950, W.M.A. Brooke 6081 (BM!, NY!); Jose Carrasco Torrico, 27 Jun 1996, M. Kessler 6763 (NY!, UC); idem, 02 Jul 1996, M. Kessler 6877 (NY!, UC); Tiraque, 10 May 2005, E. Zurita 390 (MO!). La Paz: Bautista Saavedra, 27 Apr 1993, P. Gutte 559 (LPB!); Franz Tamayo, 24 Feb 2008, A.F. Fuentes Claros 11982 (MO!, UC); idem, 04 Mar 1980, J. Krach 9207 (LPB!); idem, 06 Apr 2009, M.I.L. Rivera 599 (MO!); Inquisivi, 21 Dec 1989, L.J. Dorr 6764 (LPB!, NY!); idem, 18 Feb 1989, M.A. Lewis 35242 (LPB!, MO!, NY!, UC); idem, 09 Mar 1991, M.A. Lewis 38230 (MO!); idem, 04 Sep 1991, M.A. Lewis 39744 (F, GH!, LPB!, MO!); Larecaja, 1818, G. Mandon 1560 (BM!, G!, K!, NY!); Murillo, 16 May 1985, J.C. Solomon 13742 (LP!, LPB!, MO!, NY!); Nor Yungas, XI/1900, O. Buchtien 2751 (P!); idem, 07 Mar 1969, H. Doppelbaur s.n. (MO!); Pedro Domingo Murillo, 17 Mar 2012, T.E. Almeida 3121 (BHCB!, LPB!); Pongo, s.d., W.M.A. Brooke 5456 (BM!, NY!); Unduavi, 1890, A.M. Bang 734 (B!, BR!, GH!, K!, LE!, MO!, US!); idem, 30 Mar 1977, J.D. Boeke 1375 (NY!); idem, Feb 1914, O. Buchtien 420 (B!, BM!, G!, GH!, K!, NY!, P!); idem, 19 Jun 1912, E. Rosenstock 49 (B!, P!). Santa Cruz: Manuel M. Caballero, 11 Apr 2004, R. Nuñez Cabrera 682 (MO!, NY!, UC, USZ!); idem, 08 Mar 2012, T.E. Almeida 3083 (BHCB!, HSTM!, LPB!); s.l., 26 Oct 1928, J. Steinbach 8531 (BM!, GH!, K!, MO!, NY!). Tarija: Aniceto Arce Ruiz, 13 Jun 2004, I. Jimenez 2420 (NY!, UC); Arce, 10 Nov 2004, H. Huaylla 1509 (MO!); idem, 27 Jun 2005, H. Huaylla 1882 (MO!); idem, 12 Nov 2004, M. Serrano 5082 (MO!); idem, 12 Nov 2004, M. Serrano 5136 (MO!); idem, 03 Feb 2005, M. Serrano 5945 (MO!); O’Connor, 22 Oct 1983, S.G. Beck 9651 (LPB!); s.l, s.d., M. Cárdenas 1036 (GH!); s.l., 07 Mar 1969, H. Doppelbaur 291 (M!); s.l., 06 May 1928, [illegible] 1569 (B!); s.l., 21 Aug 1926, [illegible] 2559 (B!). ECUADOR. Pichincha: Quito, s.d., W. Jameson 73 (G!, K!). PERU. Amazonas: s.l., 03 Aug 1962, J.J. Wurdack 1592 (GH!). Ancash: Carhuaz, 14 Feb 1985, D.N. Smith 9571 (MO!, USM); idem, 18 Jul 1985, D.N. Smith 11264 (BM!, ENAG, F, GH!, MICH, MO!, NY, UC, USM); Huari, 08 May 1986, D.N. Smith 12415 (BM!, F, LPB!, MO!, NY, UC); idem, 13 Jun 1986, Smith 12648 (MO!); Yungay, 13 Jan 1985, Smith 9150 (GH!, MO!, USM); idem, 17 Apr 1985, D.N. Smith 10326 (MO!, USM); idem, 19 Apr 1985, D.N. Smith 10463 (MO!, USM). Apurimac: Abancay region, Oct 1935, students of Santander C. s.n. (UC); Abancay, Tamburco, 6 Jun 2015, V. Zuñiga 452 (USM). Cusco: s.l., 31 May 2002, W.L. Galiano 4034 (MO!); s.l., 14 Feb 1987, P. Núñez Vargas 6988 (MO!); s.l., 10 Jun 2002, L.Valenzuela Gamarra 238 (NY!, MO!); La Convención, 11 Jul 2003, E. Bonino 832 (MO!); idem, 23 Jul 2003, E. Bonino 909 (MO!, UC); idem, 26 Mar 2004, I. Huamantupa 4428 (MO!); idem, 21 Sep 2005, I. Huamantupa 6844 (MO!, USM!); idem, 30 Mar 1939, C. Vargas 4505 (MO!); Urubamba, 23 Apr 1982, B. Peyton 51 (MO!); idem, 04 Jul 1982, B. Peyton 766 (MO!); idem, 17 Aug 1982, B. Peyton 1053 (GH!, MO!); idem, 05 Nov 1988, A. Tupayachi 758 (GH!, MO!, NY!); idem, 30 Dec 1963, L. Valenzuela 14983 (GH!). Huánuco: Yanano, 13-16 May 1923 J.F. Macbride 3826 (G!). La Libertad: Pataz, 24 Feb 1986, K. Young 2988 (NY); s.l., 23 Jun 1974, A. López M. 8129 (G!, MO!, NY!). Lambayeque: Ferreñafe, 9 Jun 2012, L. García Llatas s.n. (USM). San Martín: Mariscal Cáceres, Huicungo, 15 Jun 2001, B. León 5249 (NY!, USM).

Figures

Figure 2. Adetogramma chrysolepis (Hook.) T. E. Almeida. A Habit B Rhizome scale C Sterile lamina detail showing free venation and laminar scales D Fertile lamina detail showing sori, paraphyses, and laminar scales E Paraphysis detail. Drawings A-D by H. Fukuda from Dorr et al. 6764 (NY); drawing E by Juliana Ventura from T. E. Almeida & L. L. Giacomin 3121 (BHCB). Scale bars: A = 5 cm, B-E = 1 mm.

Figure 3. Adetogramma chrysolepis (Hook.) T. E. Almeida. A, B Scanning electron micrography (SEM); magnification 75 x and 1750 x, respectively A Sori showing sporangia and paraphysis (the latter indicated by an arrow head) B Spores. Images from Almeida & Giacomin 3121 (BHCB). Scale bars: A = 500 μm, B = 20 μm.

Figure 4. Adetogramma chrysolepis (Hook.) T. E. Almeida. A Fertile and sterile fronds B Detail of abaxial surface of fertile frond, showing laminar scales and paraphyses C Juvenile sterile leaves. (A) and (B) from C. Martin 730 (SI), (C) from C. Martin 479 (SI).

Figure 5. Distribution of Adetogramma chrysolepis.