Goyazia villosa (Gardner) R. A. Howard

Figueira, Maurício, Schindler, Bianca, Onofre de Araujo, Andréa, Chautems, Alain, Perret, Mathieu, da Silva, Nílber Gonçalves, Alves, Ruy José Válka & Simon, Marcelo Fragomeni, 2024, George Gardner’s enigmatic species Goyazia villosa (Gesneriaceae) finally rediscovered, PhytoKeys 246, pp. 265-276 : 265-276

Goyazia villosa (Gardner) R. A. Howard , J. Arnold Arbor. 56 (3): 367. 1975.

≡ Tapina villosa Gardner. Type: Brazil. Goyaz [Tocantins]: in dry clefts of rocks near the summit of the Serra de Natividade, February 1840, G. Gardner 3875 (lectotype: K [barcode] K 000509791 image!; isolectotypes BM [barcodes] BM 000793292, BM 000883802 images!, CGE [barcode] CGE 00055228 image!, E [barcodes] E 00062346, E 00062347 images!, FI [barcode] FI 009756 image!, G [barcodes] G 00365532, G 00365534, G 00365541 images!, P [barcodes] P 00587409, P 00587410, P 00587411 images!, W [barcodes] W 0005013, W 0192283 images!).

Description.

Herb, rupicolous, with a perennial scaly rhizome at the base of the roots, stem 1–10 cm long, erect, unbranched, green in vivo, villous. Leaves in basal pseudo-rosette or opposite and arranged in 2–5 pairs along the stem, anisophyllous, internodes 0.2–3 cm long, petiole 2–8 mm long, terete, green, villous, blade 1–3.5 × 0.3–2.5 cm, ovate-elliptic or elliptic, symmetrical, membranaceous, pubescent on both faces, tector trichomes unicellular or multicellular uniseriate, base obtuse or cuneate, apex acute or acuminate, margin serrate with 5–14 teeth, lateral veins 4–5 per side. Inflorescence composed of a single flower on leaf axil, pedicel 1.8–3.5 cm long, erect, villous; sepals subequal, 3–4 × 0.5 mm, linear-lanceolate, subulate at the apex, villous; corolla tubular-infundibuliform, pseudo-actinomorphic, 10–12 mm long, white at base, tube dark purple, lobes 5, 3–4 mm long, subequal, marked with 3 lines of purple and faint dots, with white towards the apex, margin subdentate, throat with wine red dots; stamens 4, filaments glabrous, anthers coherent, nectary dehiscent, annular; ovary superior, ovoid, villous, style 3.5–4 mm long, villous at base, glabrous at the apex, stigma stomatomorph. Fruit a dry loculicidal capsule, dehiscent at the apex, seeds black.

Additional specimens examined.

Brazil • Tocantins, Palmas, Serra do Lajeado ; 09 ° 58 ' 55 " S, 48 ° 19 ' 00 " W; 295 m, fl.; 5 Apr 2017; R. J. V. Alves & N. G. Silva 12586 ( CEN, R) ; • Tocantins, Ponte Alta do Tocantins, ESEC Serra Geral do Tocantins, rio das Balsas, Cachoeira da Fumaça ; 11 ° 09 ' 22 " S, 47 ° 00 ' 43 " W; 467 m, fl. and fr.; 2 Mar 2021; B. Schindler, M. Figueira, M. F. Simon, V. F. Gomes, W. B. Silva 41 ( CEN, RB) ; • idem; 11 ° 09 ' 22 " S, 47 ° 00 ' 45 " W; 465 m, fl.; 15 Mar 2022; M. Figueira, B. Schindler, M. F. Simon, R. R. Souza, V. F. Gomes, W. B. Silva 1808 ( CEN, G [barcode] G 00447873 , R, RB, UB) .

Distribution and habitat.

The species is endemic to the state of Tocantins, Brazil (Fig. 1 ). It has been recorded in the municipalities of Natividade, Palmas, and Ponte Alta do Tocantins. Recent records were made in a humid and shaded hillside, in the Serra do Lajeado, at around 295 m of altitude (R. J. V. Alves & N. G. Silva 12586), and also in a riparian forest on shaded humid sandstone walls in the locality known as Cachoeira da Fumaça, in the southwest corner of the EESGT, at around 470 m of altitude (B. Schindler et al. 41 and M. Figueira et al. 1808) (Fig. 3 A – C ). Description of the habitat by Gardner on the specimen label indicates that the plant was collected “ in dry clefts of rocks near the summit of the Serra de Natividade ”. In contrast, our field observations suggest that Goyazia villosa grows in humid and shaded sites. Preference of G. villosa for drier sites is however not unlikely because of its rhizomes with fleshy scales (Fig. 2 B ) that allow the plant to become dormant during the dry season, and grow and reproduce during the rainy season. This feature has already been reported for other genera of Gloxiniinae ( Araújo et al. 2010).

Phenology.

Flowers and fruits between December and April during the rainy season.

Etymology.

The genus name is a reference to the state of Goiás (formerly spelled as Goyaz in old Portuguese orthography). The plant was collected in an area that now belongs to the state of Tocantins. The specific epithet refers to the trichomes found throughout the plant.

Conservation status assessment.

Goyazia villosa is currently known from only three localities, where it inhabits a very specific habitat. It has an AOO of 12 km 2 and EOO 9103.44 km 2. Analysis of land use within G. villosa range ( EOO) revealed a reduction of 1616 km 2 over 35 years, which represents an increment of anthropic areas from 9.0 % in 1986 to 17.7 % in 2021. Considering its AOO <500 km 2, number of locations ≤ 5, and continuing decline in extent of occurrence, we preliminary assign a category of endangered (EN) for G. villosa under IUCN criterion B 2 ab (i).

Although known from only three localities and inhabiting a very specific habitat, G. villosa occurs in a region that still harbors much of its native vegetation, despite the observed vegetation loss over its range. The two newly reported populations are between 100 and 200 km from the type collection. The area covered within its current range harbors a number of unexplored sites of potential occurrence of G. villosa , including several mountain ranges, which could increase its AOO. Recently documented habitats of G. villosa are either unsuitable for agriculture (rocky outcrops) or protected by environmental regulations (riparian forests), which reduces the chances of loss of this specific habitat. The overall extent of occurrence of G. villosa in eastern Tocantins includes a large protected area ( EESGT). One negative aspect in the conservation of this species is that the population found in Cachoeira da Fumaça within the EESGT may suffer from trampling since a patch of individuals of G. villosa is located along a trail used by the numerous visitors to the waterfall. The rarity of G. villosa is probably a result of strong habitat specificity and insufficient collecting effort across its geographic range, which could explain the paucity of records. Finally, more sampling is needed to understand its entire geographical range.

Figures

Figure 1. Location of the type collection of Goyazia villosa made in 1840 (circle) and new records made in the municipality of Palmas in 2017 (diamond) and Estação Ecológica Serra Geral do Tocantins (EESGT) in 2021 and 2022 (triangle). Brazilian states: BA (Bahia), MA (Maranhão), PI (Piauí), TO (Tocantins). Track of G. Gardner based on the Atlas dos Viajantes no Brasil (https://viajantes.bbm.usp.br/). Map produced with QGIS (QGIS Development Team 2024).

Figure 2. Goyazia villosa (Gardner) R. A. Howard A habit B detail of rhizome with fleshy scales C detail of leaf trichomes on the adaxial surface D front view of corolla E lateral view of corolla F detail of sepals, ovary, and ring nectary (corolla removed) G stamen H immature fruit I open capsule. Photographs by M. Figueira and B. Schindler from M. Figueira et al. 1808.

Figure 3. Habitat and habit of Goyazia A Cachoeira da Fumaça at the Estação Ecológica Serra Geral do Tocantins B habitat of G. villosa on rocky outcrops C frontal view of G. villosa attached to sandstone rocks D lateral view of individuals of G. petraea E, F habit of G. rupicola. Photographs: A – C, E M. Figueira and B. Schindler D and F A. O. Araujo; photos from collections: B, C M. Figueira et al. 1808 D A. O. Araujo et al. 1065-24 E M. Figueira et al. 1897 F A. O. Araujo et al. 1082.