Virola chrysocarpa D.Santam. & Aguilar, 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

3. Virola chrysocarpa D.Santam. & Aguilar sp. nov. Figs 12 , 13 , 14

Diagnosis.

Species similar to Virola koschnyi due to many characteristics of the leaf, including overall shape, number of lateral veins and stalked trichomes. It differs in leaf blades with pubescent adaxial surfaces that are rough to the touch in herbarium specimens (vs. adaxial surface glabrous to glabrescent and smooth) and abaxial surfaces that are hirsute to hirsutulous (vs. tomentose) with trichomes that have few (3-6 vs. 4-10), but long branches (0.2-0.6 mm vs. 0.1-0.2 mm long), staminate flowers with a longer filament column (1.3-1.5 mm vs. 0.7-0.9 [-1.4)] mm long) and fruits with an acute to apiculate apex (vs. typically obtuse).

Type.

Costa Rica. Puntarenas: Golfito, Parque Nacional Corcovado, Estación Sirena, 10 m elev., 06 Feb 1994 (♂ fl), R. Aguilar 3082 (holotype: CR! [9864]; isotypes: CR! [201389], LSU! [0193694, LSU00199098], MO! [5551151, MO280080], USJ! [60813]).

Description.

Tree 15-45 m × 25-50 cm DBH; bark sometimes described as reddish to reddish-brown. Exudate described as light red but without specifying from which part or red from the trunk. Twigs 0.18-0.28 cm thick, terete, flattened laterally to slightly angulate, hirsute tomentose, trichomes dendritic, yellowish or very pale brown. Leaves: petiole 1-1.6 (-2) × 0.15-0.28 cm, canaliculated, pubescent, the trichomes dendritic; leaf blades (17.5-) 24.2-28.8 × 7.6-10 cm, obovate to oblong; adaxial surface of mature leaves olivaceous, brown to greyish when dry, hirsute to hirsutulous, asperous (in new leaves hirsute, the trichomes dendritic-stellate, pediculate, asperous to the touch); abaxial surface similar in colour to the adaxial surface when dry, densely hirsute to hirsutulous, trichomes dendritic to dendritic-stellate, yellowish to pale brown, pediculate, with 3-6 branches, the branches 0.2-0.6 mm long, persistent; lateral veins 28-32 per side, with 5-7 (-11) veins per 5 cm, (0.5-) 0.7-1.3 cm apart, the same colour as the adaxial surface or sometimes contrasting in colour, on adaxial surface flat to slightly sunken, on abaxial surface conspicuous and raised, straight to slightly arcuate, anastomosing near the margin, forming an intramarginal vein; tertiary veins usually inconspicuous adaxially, conspicuous abaxially; midvein adaxially flat, pubescent, abaxially raised, rounded, pubescent; base usually markedly cordate, not revolute, flat; margin flat, sometimes ciliolate; apex acuminate. Staminate inflorescences 4-8.5 cm long, usually at nodes lacking leaves or, on few occasions, in the axis of leaves, axes slightly flattened, densely pubescent, the trichomes dendritic, yellowish to pale brown; peduncle 1.5-4 × 0.13-0.19 (-0.3) cm; bracts 0.5-0.8 × 0.3-0.5 cm, pubescent on both sides, caducous; terminal fascicles dense, with 15-30 + flowers. Staminate flowers with the pedicel 2.8-3.5 mm long; receptacle 2-4 mm wide; perianth 2-3 mm long, subglobose to rhomboid, yellow when fresh, connate for 0.6-1.5 mm of length, abaxial surface pubescent, with pale brown, yellowish or golden trichomes, adaxial surface with few scattered trichomes, especially on the lobes; lobes 3, 1.5-2.3 × 0.6-1.5 mm; stamens 3, the filament column 1.3-1.5 mm long, thin, not constricted at the apex; anthers 0.6 mm long; apiculus apparently absent, the apex obtuse; pollen 28 µm, with bilateral symmetry, boat shaped to elliptic grain, exine reticulate, exine structure tectate-perforate (based on Lambright 1981; Skutch 4260, US). Pistillate inflorescences and flowers not seen. Infructescence 3.2-7.5 cm long, 1-2 fruits (sometimes 4 in an immature infrutescence), peduncle 1.2-5 × 0.18-0.27 cm. Fruits 2.4-2.9 × 1.7-1.8 cm, ellipsoid, sessile, densely tomentose to glabrate, the trichomes dendritic, brown to brown-reddish, the surface smooth to rugulose, the line of dehiscence smooth, canaliculate, to slightly carinate, the base rounded, the apex acute to apiculate, yellow, orange or ferruginous (possibly by the indumentum) when fresh; pericarp 1.8-2.5 mm thick; pedicel 0.5-0.8 cm long; seed ca. 1.7-2.1 × 1.3-1.4 cm, the testa pale brown to blackish when dry, slightly grooved to almost smooth; aril usually described as red or pink when fresh, brown or yellowish when dry, oily, thick, laciniate in narrow bands or wide distally. Germination epigeal, seedling cryptocotylar ( Ley López and Chacón Madrigal 2017; as V. koschnyi ).

Distinctive characters.

Virola chrysocarpa is distinguishable for its leaf blades with pubescent adaxial surfaces that are rough to the touch in mature leaves (at least in herbarium specimens) and abaxial surfaces that are hirsute to hirsutulous with trichomes with long branches (0.2-0.6 mm long) ( Fig. 3C ), numerous lateral veins (28-32 per side), tertiary veins that are usually conspicuous on both surfaces ( Figs 3C , 8C ) and with a base that is usually markedly cordate; staminate inflorescences that are little-branched ( Fig. 14D ) with flowers with filament columns that are much longer (1.3-1.5 mm) than the anthers (0.6 mm); and fruits that are acute to apiculate at the apex ( Fig. 14E, F, H ). Additionally, as far as we are aware, this is the only Mesoamerica species that is completely deciduous (i.e. all leaves fall off the tree) ( Fig. 13A ).

Etymology.

The specific epithet, chrysocarpa, is derived from the Greek chryso (gold) and carpo (fruit). This is in reference to its common name, "fruta dorada" (golden fruit), which is used by locals of the Osa Peninsula, Costa Rica, where this species is frequent.

Distribution.

Virola chrysocarpa is known from Costa Rica (Puntarenas and San José) and Panama ( Chiriquí) ( Fig. 9C ). It is found in the Pacific slope at 0-700 m in elevation.

Preliminary conservation status.

Possible Near Threatened: This species has a small estimated AOO (60 km2), though a relatively large estimated EOO of 5,334 km2. Its eighteen known specimens represent eleven localities. This limited number of specimens warrants a Possible NT status, though additional collection efforts may demonstrate the lack of conservation threat for this poorly known species.

Common names.

Costa Rica: fruta dorada. Panama: bogamani.

Phenology.

Herbarium specimens of flowering Virola chrysocarpa have been collected in December to March and fruiting specimens from March to June. Herbarium specimens with pistillate flowers were not observed. In the Osa Peninsula, leaves fall completely during the dry season, which occurs in November to February ( Allen 1956; Quesada Quesada et al. 1997; and R. Aguilar pers. obs., 2015, 2017, 2018, 2019).

A study of vegetative, flowering and fruiting phenology has been published by Lobo et al. (2008; as V. koschnyi ) in the Osa Peninsula and Golfo Dulce, Costa Rica. In this study, flowering was documented in January and February, when the canopy was deciduous. Fruiting occurred in the rainy season from June to August.

Field characters.

Plants are large trees with boles that are straight and do not begin to branch until they reach a great height, with buttresses, up to 1.6-2.5 m tall. Bark is sometimes described as finely fissured. The new leaves are lime green in colour. Twigs, petioles and leaf blades on both surfaces (especially the youngest ones) are covered with golden, brown-reddish to rusty-red trichomes. Flowers have yellow or yellow-cream perianth and anthers. Mature fruits are yellow, orange or ferruginous (possibly due to their indumentum). Seeds are brown or blackish and covered with a red to scarlet aril.

Discussion.

Virola chrysocarpa resembles a morphological group of species from South America that includes V. caducifolia W. A. Rodrigues, V. decorticans Ducke, V. guggenheimii W. A. Rodrigues, V. multicostata Ducke, V. multinervia Ducke, V. polyneura W. A. Rodrigues and V. rugulosa (Spruce) Warb. These species are characterised by having leaves that are evidently pubescent, some with dendritic to irregularly dendritic pediculate trichomes on the abaxial surface and leaf blades with numerous, conspicuous and comparatively dense lateral veins; staminate flowers with anthers that are subequal to or shorter than the filament column; and fruits with thick pericarp. Additionally, these species tend to be large, sometimes deciduous trees with cordate leaf bases and staminate flowers with the anthers that are obtuse at the apex. Table 5 presents the differences between these species and V. chrysocarpa .

In Mesoamerica, Virola chrysocarpa resembles and has been confused with, V. koschnyi (e.g. Allen 1956; Quesada Quesada et al. 1997; Jiménez 2007; Aguilar et al. 2017 onward) ( Figs 3G , 4F , 17 ), from which it differs by the characteristics included in the diagnosis. Additionally, V. chrysocarpa is a deciduous (vs. evergreen) species of the Pacific slope (vs. Caribbean slope). In the region, Virola chrysocarpa can also be confused with V. megacarpa from Panama for its leaf blades with dense lateral veins and a prominent marginal vein, as well as pediculate trichomes on the abaxial leaf surface; however, V. megacarpa has more lateral veins [(32-) 40-50 vs. 28-32 per side], the fruits are larger (4-5.7 × 2-2.9 cm vs. 2.4-2.9 × 1.7-1.8 cm) and with an acuminate to rostrate apex (vs. apex acute to apiculate) ( Fig. 4E, P ) and thick pericarp (3-6 mm vs. 1.8-2.5 mm).

Notes.

The illustration presented in Manual de Plantas de Costa Rica ( Jiménez 2007) as V. koschnyi is a mix of these two species. The branch with leaves and inflorescences (and, most likely, the trichomes) are based on material that represents V. chrysocarpa (R. Aguilar 3082, 3125), while the other parts of this illustration (staminate flowers and fruits) represent V. koschnyi and are based on F. Araya 197 (fl), and U. Chavarría 1918 (fr) (B. Hammel pers. comm., Feb 2019).

Specimens examined.

Costa Rica. Puntarenas: Osa, Parque Nacional Corcovado, Estación San Pedrillo, 10-100 m elev., 19 Feb 1994 (♂ fl), R. Aguilar 3125 (CR-2 sheets!, MO!); Osa, Reserva Forestal Golfo Dulce, Mogos, a 20 km. de Chacarita, 17 Apr 2008 (fr), R. Aguilar 11190 (NY!*, USJ!); Rincón, Banegas centro del pueblo, 49 m elev., 15 Dec 2008 (♂ fl), R. Aguilar 11569 (MO!, NY n.v., PMA!*); forest below Esquinas Experiment Station Residence, area between Río Esquinas and Palmar Sur de Osa, 100 ft [30 m] elev., 30 May 1950 (fr), P. H. Allen 5554 (CR-2 sheets!, MEXU!*, MO-2 sheets! [photo & dried specimen], PMA!*); Golfito, Estación Agujas, 300 m elev., 18 Feb 1998 (♂ fl), A. Azofeifa 683 (CR-2 sheets!, MO!); Osa Península, Rancho Quemado, ca. 15 km W of Rincón, 200-400 m elev., 28 May 1988 (fr), B. Hammel et al. 16864 (CR!, INPA!*, MO!, PMA!*); Rancho Quemado, a lo largo de Río Riyito en la pura entrada al valle, 200 m elev., 31 Mar 1991 (imm fr), B. Hammel et al. 18186 (CR!, MEXU!*, MO!, USJ!); Parque Nacional Corcovado, Pavo Forest, 0-150 m elev., 16 Jun 1988 (fr), C. Kernan & P. Phillips 582 (CR!, INPA!*, MO!); Parque Nacional Corcovado, Ollas trail, 0-100 m elev., 09 Jan 1989 (fl bud), C. Kernan et al. 876 (CR!, MEXU!*, MO!, USJ!); Parque Nacional Corcovado, Llorona Forest, 0 m elev., 16 Jan 1989 (♂ fl), C. Kernan & P. Phillips 913 (CR!, INPA!*, MO!, USJ!); Parque Nacional Corcovado, Sirena, 1-20 m elev., 15 Jun 1990 (fr), G. Maass 34 (CR!, MO!); Golfito, Parque Nacional Corcovado, sendero Las Ollas, 100-150 m elev., 21 Mar 1995 (fr), J. F. Morales 3690 (CR!, LSU!, MO); Aguabuena, 3 km W of Rincón, 120 m elev., 06 May 1993 (fr), K. Thomsen 371 (CR-2 sheets!). San José: [ Pérez Zeledón], Vicinity of El General, 700 m elev., n.d., Feb 1939 (♂ fl), A. F. Skutch 4241 (MO!); [ Pérez Zeledón], Vicinity of El General, 740 m elev., n.d. Mar 1939 (♂ fl), A. F. Skutch 4260 (MO!, US n.v.); Tarrazú, San Lorenzo, camino entre cerro Pito y cerro Toro, 600-700 m elev., 26 May 1998 (fr), O. Valverde 970 (CR!, MO!, USJ!). PANAMA. Chiriquí: Progreso, no elev., Jul–Aug 1927 (fr, at GH, NY), G. P. Cooper & G. M. Slater 175 (F!*, GH!*, NY!*).

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 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 9. Geographic distribution of Virola allenii (A), V. amistadensis (B), V. chrysocarpa (C), V. elongata (D), V. fosteri (E) and V. guatemalensis (F).

Figure 12. Virola chrysocarpa A branch with leaves and fruits B base of young leaf C fruit D partial staminate inflorescences E staminate flower. Drawn by Pedro Juarez, based on R. Aguilar 11190 (A-C) and R. Aguilar 11569 (D, E).

Figure 13. Vegetative characteristics of Virola chrysocarpa A tree showing deciduous nature of the species B trunk C buttress D branch showing new leaves E leaf blades on abaxial surface F leaf blades on abaxial surface, showing margin detail and venation G leaf apex H new branch and leaf base. Photos by Reinaldo Aguilar.

Figure 14. Fertile characteristics of Virola chrysocarpa A branch with staminate inflorescences B staminate inflorescences C staminate flower buds and open flower D Infructescence E open fruit F seeds. Photos by Reinaldo Aguilar.

Figure 17. Virola koschnyi A lower trunk and buttresses B trunk C branching D leaf blades on abaxial surface E leaf blades on adaxial surface F twig, petiole and leaf base G leaf venation on adaxial surface (left) and abaxial surface (right) H branch with fruits, showing the interior part of the fruit I seed J mature fruit. All photos by Reinaldo Aguilar from https: // sura. ots. ac. cr / florula 4 / index. php, except G by D. Santamaria-Aguilar.