Virola otobifolia D.Santam., 2019

Santamaria-Aguilar, Daniel, Aguilar, Reinaldo & Lagomarsino, Laura P., 2019, A taxonomic synopsis of Virola (Myristicaceae) in Mesoamerica, including six new species, PhytoKeys 134, pp. 1-82 : 1

13. Virola otobifolia D.Santam. sp. nov. Figs 7D , 23 A–E , 26

Diagnosis.

Species most similar to Virola macrocarpa in having leaf blades that are discolorous abaxially with stellate, sessile trichomes with a reddish central portion and similar number of lateral veins (10-16) that are not densely spaced. However, it differs in its leaves with dense, but inconspicuously pubescent leaf undersides (vs. inconspicuously puberulent) with 2-4 veins per 5 cm that are 1.7-3 cm apart (vs. 4-5 veins per 5 cm, 0.8-1.5 cm apart) and fruits that are (2.7-) 3.5-4.5 × (1.9-) 2.3-2.9 cm, densely tomentose with persistent trichomes, a rugose surface when dry and a line of dehiscence that is conspicuously carinate (vs. 2.7-3.3 × 2-2.3 cm, tomentellous, with caducous, dust-like trichomes, a smooth surface when dry, the line of dehiscence slightly carinate), as well as the production of thicker pericarp [(2.7-) 3-4.7 mm vs. 1.8-3 mm thick].

Type.

Panama. [ Panamá: Chepo], El Llano Cartí road 6.9 km N of Panamerican Highway, 350-500 m elev., 23 Jan 1977 (fr), J. P. Folsom 1440 (holotype: MO-2 sheets! [2601823, MO117643, 5551400, MO299335]; isotype: PMA!* [101093, PMA111119]).

Description.

Tree 6-30 m × 24.9-37.3 cm DBH; bark not described. Exudate from the trunk sometimes described as red, watery-red, or black-reddish. Twigs 0.23-0.34 cm, terete to slightly flattened, glabrescent to puberulent, trichomes stellate to irregularly stellate, ferruginous to greyish. Leaves: petiole (1-) 1.3-2 × 0.19-0.44 cm, flat to very slightly canaliculate, tomentose, the trichomes stellate; leaf blades (14-) 18.2-42.5 × (4.1-) 7.3-14.2 cm, oblong to elliptic; adaxial surface of mature leaf blades brown (sometimes shining) when dry, glabrous or sometimes with scattered stellate trichomes (especially along the veins), the surface smooth; abaxial surface when drying whitish-greyish or sometimes very light brown, dense but inconspicuously pubescent, trichomes stellate, sessile, the central part of the trichome usually reddish, contrasting in colour with the hyaline branches to reddish-clear, with 4-11 branches, the branches ± 0.01-0.05 mm, persistent; lateral veins 10-16 per side, 2-4 veins per 5 cm, 1.7-3 cm apart, the same colour as the adaxial surface, on adaxial surface flat to slightly sunken, on abaxial surface slightly elevated, arcuate, slightly anastomosing near the margin and without forming a very marked intramarginal vein; tertiary veins barely visible on both surfaces; midvein adaxially elevated, but submerged in a channel, abaxially raised, triangular to rounded, tomentose; base acute to obtuse, sometimes slightly cordate, not revolute, flat; margin flat to slightly revolute; apex acuminate. Staminate inflorescences 3.5-9.5 cm long, axillary either at a leaf or at a leafless node, axes flattened or irregularly flattened, tomentose, with trichomes irregularly stellate to irregularly dendritic, brown to ferruginous; peduncle 1.4-2.2 × 0.22-0.34 cm long; bracts not seen; terminal fascicles lax, with 5-13 flowers. Staminate flower with the pedicel 1.5-2 mm long; receptacle 0.7-1.5 mm wide;; perianth 2.5-2.8 mm long, infundibuliform, yellow or brown when fresh, connate by 0.9-1.5 mm long, abaxial surface pubescent with brown trichomes, adaxial surface glabrous or with few trichomes close to the base; lobes 3 (4), 1.2-1.5 × 0.9-1.1 mm; stamens 3 (-6), the filament column 0.9-1 mm long, straight and very thickened throughout its length, fleshy, constricted at the apex; anthers 0.6-1 mm long; apiculus ca. 0.1 mm long, acute to apiculate, connate or slightly separate. Pistillate inflorescences 3.2-4 cm long (immature), axillary, axes flattened or irregularly flattened, tomentose, with trichomes stellate, brown to ferruginous; peduncle 0.6-1.2 × ca. 3.2 cm long; bracts not seen. Pistillate flowers not seen. Infructescence 3.2-5 cm long, with (1-) 2-4 fruits, peduncle 1-3.5 × 0.35-0.53 cm. Fruits (2.7-) 3.5-4.5 × (1.9-) 2.3-2.9 cm, ellipsoid, shortly stipitate, densely tomentose, the trichomes stellate, ferruginous, persistent, the surface rugose when dry, the line of dehiscence conspicuously carinate, the base obtuse to subtruncate, the apex acute to acuminate, brown (possibly by pubescence), although presumably green when fresh; pericarp (2.7-) 3-4.7 mm thick; pedicel 0.5-0.8 (-1) cm long; seed 2.5-2.8 × 1.5-1.7 cm, the testa dark brown when dry, markedly grooved; aril described as red when fresh, brown to blackish when dry, membranaceous, with a dry texture, thin, laciniate in narrow bands distally.

Distinctive characters.

Virola otobifolia is recognised by its large leaf blades with well-spaced lateral veins ( Fig. 8M ) and a whitish abaxial surface that is covered with stellate, sessile trichomes ( Fig. 3M ); staminate flowers that have a filament column that is straight and very thickened throughout its length, except where it is constricted at the apex and anthers that are almost the same length as the filament column; and its large fruits with thick pericarp that are densely tomentose and with a conspicuously carinate line of dehiscence ( Fig. 4C ).

Etymology.

The specific epithet refers to the similarity of the leaf blades with Otoba , another member of Myristicaceae . This epithet was, in part, inspired by the fact that some of the first collections of this new species were initially confused with this genus (as Dialyanthera Warb.; e.g. A. Gentry & S. Mori 14199, MO).

Distribution.

Virola otobifolia is only known in Panama ( Colón, Panamá and San Blas), where it is found on the Caribbean slope ( Fig. 27A ). It has been recorded between 50-850 m elevation.

Preliminary conservation status.

Virola obtobifolia is Endangered following IUCN criteria B1a and B2a. Justifying this status, it has both a small EOO (3,269 km2) and AOO (36 km2) and is known from only five localities.

Common names.

Panama: velario, miguelario; cuinur burwi, putmas (Kuna).

Phenology.

Virola otobifolia has been recorded with flowers and fruits in February to April and one collection with fruits was made in October.

Field characters.

Exudate is slow to appear and is watery and red-black. Leaf blades are whitish abaxially. Flowers have yellow perianth. Fruits are green, but appearing brown (possibly due to pubescence).

Discussion.

Specimens of Virola otobifolia have been confused with and identified as V. macrocarpa (e.g. Correa et al. 2004; Condit et al. 2011) ( Figs 4D , 7C ), probably due to the similar size of the fruits and the leaf morphology (i.e. large discolorous leaf blades, with stellate, sessile trichomes with a reddish centre, and lateral veins that are well-separated). However, it is easily distinguished by the leaf width, pubescence on abaxial surface of the leaves, the number of lateral veins, fruit morphology and habitat; a comparative table of these two species is presented in Table 7 .

Two similar species from Mesoamerica that resemble Virola otobifolia are: V. allenii ( Figs 6 , 7A ), which ocurrs in the lowland wet forest on the Pacific slope of Costa Rica and V. amistadensis ( Fig. 7B ) from montane forests of Costa Rica and Panama on the Caribbean slope. Morphological comparison between these species is presented in Table 3 .

Notes.

The holotype, deposited at Missouri Botanical Garden (MO), represents a single collection mounted on two sheets that are clearly labelled ("Sheet 1 of 2," "Sheet 2 of 2) as being parts of the same specimen (ICN Art. 8.3) ( Turland et al. 2018).

Specimens examined.

Panama. Colón: Teck Cominco Petaquilla, 200 m elev., 21 Feb 2008 (fl bud), G. McPherson 20135 (MO!); [Donoso] Westernmost part of province, site of proposed copper mine (INMET), 150 m elev., 12 Apr 2009 (fr), G. McPherson 20905 (MO!). Panamá: [Chepo] El Llano Cartí road, near El Llano, [460 m elev.], 27 Mar 1976 (fr), T. B. Croat 33725 (MO!); Cerro Jefe, Parque Nacional Chagres, [985 m elev.], 17 Jan 2002 (fr), N. Flores & R. Aizprúa B3156 (MO!); [Chepo] El Llano Cartí road 18 km from Pan-Americana Highway, 330-370 m elev., 14 Feb 1975 (fr), A. Gentry & S. Mori 14199 (MO!, SCZ!*); El Llano-Carti road, 12.7 km N from Pan American Highway, 350 m elev., 15 Feb 1975 (fl bud), A. Gentry & S. Mori 14213 (MO!); below Cerro Jefe, along road to Río Pacora, 850 m elev., 09 Jan 1986 (fr), G. McPherson 7946 (INPA!*, MO!, PMA!*). San Blas: El Llano-Cartí road, 24.5-25 km from PanAmerican highway, [250-350 m elev.], 12 Apr 1975 (♂ fl), S. Mori & J. Kallunki 5542 (MO!); El Llano-Carti road, 350 m elev., 01 Oct 1984 (fr), G. de Nevers & H. Herrera 3981 (MO!, MEXU!*, PMA!*); Cangandí, 30 m elev., 10 Feb 1986 (fr), G. de Nevers & H. Herrera 7056 (MO!, INPA!*, PMA!*); ibid, 10 Feb 1986 (fl bud), G. de Nevers & H. Herrera 7068 (MO!, INPA!*); Cangandí, 30 m elev., 27 Mar 1986 (fr), G. de Nevers et al. 7430 (MO-2 sheets!, PMA!*); ibid, 27 Mar 1986 (fl bud), G. de Nevers et al. 7448 (MO!); ibid, 27 Mar 1986 (♂ fl), G. de Nevers et al. 7530 (MEXU!*, MO!, PMA!*); ibid, 27 Mar 1986 (fl bud), G. de Nevers et al. 7605, 7607 (MEXU!*, MO!, PMA!*).

Figures

Figure 3. Trichomes in Mesoamerican Virola A Virola allenii (R. Aguilar 2224, MO) B V. amistadensis (G. McPherson 8703, MO) C V. chrysocarpa (O. Valverde 970, MO) D V. elongata (G. McPherson 13674, MO) E V. fosteri (G. McPherson 20913, MO) F V. guatemalensis (R. Cedillo 3349, MO) G V. koschnyi (R. E. Gereau et al. 3455, MO) H V. laevigata (R. Aguilar 2004, MO) I V. megacarpa (J. A. Duke 15261, MO) J V. montana (E. Bello 855, MO) K V. multiflora (R. Rueda et al. 8196, MO; inset, J. C. Sandino 3302, MO) L V. nobilis from Barro Colorado (R. J. Schmalzel 320, MO) M V. otobifolia (G. de Nevers & H. Herrera 7056, MO) N V. sebifera (F. Almeda et al. 5553, MO) O V. nobilis from Osa Peninsula (R. Aguilar 11186, MO).

Figure 4. Fruits of Mesoameican Virola, organised in groups of morphologically similar species A V. allenii (P. H. Allen 6727, GH) B V. amistadensis (G. McPherson 9715, MO) C V. otobifolia (A. Gentry & S. Mori 14199, MO) D V. macrocarpa (A. E. Lawrance 675, MO) E V. chrysocarpa (B. Hammel et al. 16864, MO) F V. koschnyi (R. Robles 1587, MO) G V. guatemalensis (S. Sinaca 1542, MO) H V. montana (J. Utley & K. Utley 5054, MO) I V. fosteri (S. Mori & J. Kallunki 4891, MO) J V. multiflora (R. Rueda et a. l 9960, MO) K V. sebifera (T. B. Croat 5959, MO) L V. elongata (J. D. Dwyer & M. Correa 8420, MO) M V. laevigata (R. Aguilar 1585, MO) N V. nobilis from Barro Colorado (T. B. Croat 8090, MO) O V. nobilis from the Osa Peninsula (G. Herrera 4222, MO) P V. megacarpa (G. de Nevers 5184, MO). Scale bars: 1 cm.

Figure 6. Virola allenii A treetop B branching C lower trunk and buttress D branch with leaves, showing the adaxial surface E leaf blades on abaxial surface F exudate of the trunk G leaf blade surfaces, adaxial (above) and abaxial (below) H petiole and leaf base I mature fruit, inset left and arrow showing the galls on leaves and branches, respectively J fruits K fruit close-up. Photos by Reinaldo Aguilar.

Figure 7. Comparisons of Virola macrocarpa with similar species in Mesoamerica A V. allenii (P. H. Allen 5763, F; inset fruits, from P. H. Allen 6727, GH) B V. amistadensis (G. McPherson 9717, MO; inset fruits, from G. McPherson 9715, MO) C V. macrocarpa (A. E. Lawrance 675, MO) D V. otobifolia (J. P. Folsom 1440, MO). Image courtesy of Field Museum (A).

Figure 8. Pattern of the lateral veins in Mesoamerican Virola A Virola allenii (K. Thomsen 1284, NO) B V. amistadensis (G. McPherson 8703, MO) C V. chrysocarpa (B. Hammel et al. 16864, MO) D V. elongata (M. Correa & R. L. Dressler 1078, MO) E V. fosteri (G. de Nevers 7226, MO) F V. guatemalensis (G. Ibarra 957, MO) G V. koschnyi (J. Miller & J. C. Sandino 1110, MO) H V. laevigata (N. Zamora & T. D. Pennington 1583, MO) I V. megacarpa (G. de Nevers 5184, MO) J V. montana (E. Lepiz & J. F. Morales 284, MO) K V. multiflora (J. Manzanares 3561, MO) L V. nobilis from Barro Colorado (R. J. Schmalzel 320, MO) M V. otobifolia (G. de Nevers et al. 7530, MO) N V. sebifera (T. B. Croat 5959, MO) O V. nobilis from Osa Peninsula (R. Aguilar 11186, MO).

Figure 23. Virola otobifolia A branch with leaf blades showing both surfaces and inflorescences B leaf blade, venation and base on abaxial surface C infructescence D fruits E detail of fruit, showing an aril of an immature fruit. Virola surinamensis. F Branch with inflorescences G, H leaf blade on adaxial (G) and abaxial surface (H). I Infructescence J detail of fruits, including a longitudinal section of an immature fruit. Photos by Rolando Perez (A, B from https: // stricollections. org / portal / index. php); Jerry Harrison (C), Alwyn H. Gentry (D, E from http: // www. tropicos. org) and John P. Janovec (F-J from http: // atrium. andesamazon. org /).

Figure 26. Virola otobifolia A branch with leaves and inflorescences B fruits. Drawn by Pedro Juarez, based on S. Mori & J. Kallunki 5542 (A) and J. P. Folsom 1440 (B).

Figure 27. Geographic distribution of Virola otobifolia (A) and V. sebifera (B).