Virola bombuscaroensis D. Santam., 2022
treatment provided by
|Virola bombuscaroensis D. Santam.|
3. Virola bombuscaroensis D. Santam. sp. nov.
Ecuador. Zamora-Chinchipe: PN [Parque Nacional] Podocarpus, Bombuscaro entrance, 04°07'S, 078°58'W, 1350 m, 25 Jan 2011 (fr), J. Homeier 4507 (holotype: MO! [accession 6863380, barcode MO-3053475]; isotypes: n.v.). Fig. 8 View Figure 8 GoogleMaps
Virola bombuscaroensis differs morphologically from all other species by the combinations of abaxial leaf surface covered by stellate, sessile trichomes, perianth of staminate flowers densely pubescent on both faces, and the column of filaments that has scattered trichomes at the base.
Tree 6-15 m tall, diameter, inner bark and exudate not described. Twigs 0.43-0.62 cm thick, terete to laterally flattened, tomentose to tomentulose, trichomes dendritic, sessile, ferruginous to whitish, the bark sometimes with small lenticels. Leaves young terminal bud 2.5-2.9 × 0.4-0.48 cm, with conspicuous veins; petiole 1.5-2.2 × 0.33-0.5 cm, canaliculate, sometimes very short alate, tomentose, the trichomes dendriform; leaf blades 23.3-30 × 7.1-10.3 cm, ovate; adaxial surface of mature leaves dries brown to olivaceous, glabrous or with very few and scattered trichomes (densely pubescent on new leaves), the surface smooth, sometimes shiny; abaxial surface when drying brown or whitish-grayish, densely pubescent, but inconspicuous to the naked eye, trichomes stellate or sometimes dendriform trichomes along the main veins, the stellate trichomes 0.1-0.2 mm diameter, sessile, the central part of the trichome (usually) reddish and contrasting in color with the hyaline to reddish branches, or the branches the same color as the central part, the dendriform trichomes ca. 0.4 mm long, ferruginous, persistent; lateral veins (13-) 18-23 per side, (3-) 4-5 veins per 5 cm, spaced (0.9-) 1.4-1.8 cm apart, on adaxial surface flat or elevated, the same color as the adaxial leaf surface or a little darker, on abaxial surface raised or flat, rounded or laterally compressed, tomentose to glabrescent, arcuate-ascending, slightly anastomosing near the margin and without forming a very marked intramarginal vein; tertiary veins slightly visible on both sides, more prominent on adaxial side; midvein adaxially slightly elevated, abaxially raised, usually rounded, tomentose; base cordate, not revolute, flat; margin flat to slightly revolute; apex acuminate. Staminate inflorescences ca. 5.4 cm long, axes flattened, tomentose, the trichomes dendritic, ca. 0.3-0.4 mm long, ferruginous; peduncle ca. 2 × 0.27 cm; main axes with 5 ramifications, the first pair opposite, the others alternate; bracts not seen. Staminate flowers (in bud) in dense terminal fascicles of 13-15+ flowers, on a receptacle 2-2.7 mm wide; perianth 2.8-3.4 mm long, obovoid, fleshy, brown when fresh, connation not seen (young flowers), external surface densely pubescent with ferruginous and dendritic trichomes, internal surface densely pubescent; lobes 3, not measured (young flowers), ca. 0.2 mm thick, without resinous punctuations when rehydrated; stamens 3, the filament column ca. 1.4 mm long, ca. 0.4 mm wide, slightly pubescent at the base, straight to slightly thickened at the base, not constricted at the apex; anthers ca. 0.9 mm long, ca. 0.4 mm wide; apiculus ca. 0.1 mm long, apiculate, separate. Pistillate inflorescences and pistillate flowers not seen. Infructescence 3-3.5 cm long, with 2-6 fruits, peduncle 1.8-3 × 0.43-0.5 cm. Fruits 2.4 × 1.8-1.9 cm, brown when fresh (probably by the pubescence), globose, stipitate, densely tomentose, the trichomes dendritic, ca. 0.1-0.3 mm long, ferruginous, and falling easily to the touch as dust, the surface slightly rugose, the line of dehiscence slightly carinate, but not very conspicuous, the base obtuse, the apex acute to obtuse; pericarp 1.6-2.2 mm thick; pedicel 0.5-0.7 cm long. Seed 1.8-1.9 × 1.2-1.4 cm, the testa whitish grayish to brownish when dry, grooved; aril color when fresh not described, blackish to brownish red when dry, the texture dry and thin, laciniate almost to the base, in narrow bands distally.
Virola bombuscaroensis can be recognized by many pubescence characters. Dendritic trichomes cover its branches, petioles, inflorescence axes, and sometimes along the main veins on the abaxial sides of leaves; the abaxial leaf surface always is marked by stellate, sessile trichomes (Fig. 4C View Figure 4 ); its fruits are covered by ferruginous trichomes that fall very easily to the touch (Fig. 6C View Figure 6 ); the perianth of staminate flowers is densely pubescent on both sides; and the column of filaments has scattered trichomes at the base. Finally, the filament column is straight, not constricted at the apex, and is longer (ca. 1.4 mm) than the anthers (ca. 0.9 mm).
The specific epithet makes reference to the Bombuscaro River in the Podocarpus National Park of southern Ecuador, where most of the collections of this new species were made.
Virola bombuscaroensis is known only from Ecuador (Zamora-Chinchipe Province) (Fig. 18A View Figure 18 ). It is found in premontane forest at elevations between 1200 to 1350 m, with a single collection from 1930 m in elevation.
Staminate flowers of Virola bombuscaroensis have been recorded in April and fruits in January. Pistillate flowers were not seen in the studied material.
Common name and uses.
Preliminary conservation status.
Virola bombuscaroensis is Critically Endangered following IUCN criterion B2a. While its very small range from only a single locality justifies this status, V. bombuscaroensis benefits from its occurrence in Podocarpus National Park and surrounding areas, which are highly protected within Ecuador ( Kleemann et al. 2022).
Virola bombuscaroensis is difficult to confuse with other species of Virola described to date. However, it shares the combination of a cordate leaf base, well-separated lateral veins, sessile trichomes on abaxial leaf surface, and fruits with a conspicuous layer of trichomes with V. excisa (described here). Other species with similar leaf morphology, but with fruits with less conspicuous trichomes include: V. calophylla (Fig. 6E View Figure 6 ), V. peruviana (Fig. 6K View Figure 6 ), and V. schultesii A. C. Sm.; they can be distinguished by the characters in Table 3 View Table 3 .
Other species with similar leaf morphology (i.e., a usually deeply cordate base and well-separated lateral veins) are: V. divergens Ducke, V. mollissima (Poepp. ex A. DC.) Warb., and V. sebifera . However, these species differ in having pediculate trichomes on the abaxial leaf surface (vs. sessile in V. bombuscaroensis ), internally puberulent staminate perianth (vs. densely pubescent), a glabrous filament column (vs. with scattered trichomes at the base; Fig. 10D View Figure 10 ) that is shorter (vs. longer) than the anthers. In fruiting material, V. divergens , and V. mollissima are covered with a thick layer of long hairs (at least 1.4 mm long) that differ from V. bombuscaroensis . While the layer of trichomes on the fruit are somewhat similar to the new species in V. sebifera , the fruits are notably smaller (1-1.9 [-2.1] × 0.7-1.4 [-1.7] vs. 2.4 × 1.8-1.9 cm), and V. sebifera usually occurs at lower elevations.
Additionally, compared to the species with with it can be confused, V. bombuscaroensis tends to have longer staminate inflorescences and more obviously pubescent twigs, petioles, and abaxial leaf surface, very often with dendritic trichomes.
The specimen J. Homeier 1090 was cited as Virola sp. 1, in Spermatophyta / Checklist Reserva Biológica San Francisco (Prov. Zamora-Chinchipe, S-Ecuador) ( Homeier and Werner 2007), while W. Palacios & M. Tirado 13379 was discussed under V. peruviana in Flora of Ecuador ( Jaramillo et al. 2004).
Two collections from Cajamarca Department, Peru collected at 1500-1700 m elevation, J. Campos & S. Nuñez 4589 (MO!, NY-2 sheets!, UPCB [n.v.]) bearing staminate flowers and J. Campos & S. Nuñez 4188 (MO, NY, UPCB [n.v.]) bearing an infructescence with very immature fruits, have similar leaf morphology to V. bombuscaroensis (i.e., cordate base and abaxial surface with stellate, sessile trichomes). However, these specimens differ in their longer staminate inflorescences (ca. 8 cm vs. ca. 5.4 cm long) and the shorter (ca. 0.4 mm vs. ca. 1.4 mm long), glabrous (vs. pubescent) filament column. Additional, more complete material is needed to assess whether these are conspecific. These specimens have been identified as V. calophylla and duplicates may have been distributed under this name.
Ecuador. Zamora-Chinchipe: Area of the Estación Científica San Francisco, road Loja-Zamora , ca 35 km from Loja, 03°58'S, 079°04'W, 1930 m, 6 Apr 2002 (fl ♂), J. Homeier 1090 (MO!); Zamora cantón, Parque Nacional Podocarpus, guardería Rio Bombuscaro , 04°05'S, 078°57'W, 1200 m, [s.d.] Jan 1995 (fr), W. Palacios & M. Tirado 13379 (MO!, UPCB [n.v.]) GoogleMaps .
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.