Vanilla capixaba Fraga & D.R. Couto, 2017

Fraga, Claudio Nicoletti De, Couto, Dayvid Rodrigues & Pansarin, Emerson Ricardo, 2017, Two new species of Vanilla (Orchidaceae) in the Brazilian Atlantic Forest, Phytotaxa 296 (1), pp. 63-72 : 64-66

Vanilla capixaba Fraga & D.R. Couto , sp. nov. ( Figs. 1 , 2 )

The new species resembles Vanilla cristagalli Hoehne (125: 1944) and Vanilla dubia Hoehne (126: 1944) but may be easily distinguished by its smaller sepals and widest petals, the lip smaller but the midlobe lobe larger with 10–12 rows of tuberculate papillae, near of the base of the midlobe becoming enlarged to form a suborbicular tuft of trichomes towards the apex that covers almost surface and smaller column with a glabrous ventral surface.

Type: — BRAZIL. Espírito Santo: Alegre, Alto Serra da Roseira, Floresta Estacional Semidecidual, 20°47’45.4”S and 41°31’33.7”W, 610 m, fl., 5 October 2009, D.R. Couto 1270 (holotype RB!, isotype MBML!).

Hemiepiphyte, long scandent. Stem flexuous, cylindrical, succulent, slightly sulcate, glabrous, dark green; internodes 40–85 × 3.5–4.2 mm. Leaves 10.4–13.6 × 1.9–2.8 cm, alternate, linear-lanceolate, thick to succulent, glabrous, dark green, apex acuminate, base petiolate, petiole concave, 0.7–1.4 cm long. Inflorescence 2.2–3.1 cm long, axillar, racemose, 10–16 flowers, successive flowered, 1–2 flowers at anthesis simultaneously, occasionally more; bracts 3–5 mm long progressively smaller toward the apex, alternate, ovate, coriaceous, subpatent, concave, apex acute. Flowers pedicellate; pedicel with ovary 2.2–4.1 cm long, geniculate, greenish along the ovary and dark green at the apex; sepals free, dorsal sepal 4.7–5.3 × 0.8–1.2 cm, lateral sepals 4.4–4.8 × 0.7–1.2 cm, oblanceolate, thick, concave, green to whitish-green becoming clear upon maturity in both surface, apex obtuse, margin reflexed at apex; petals 4–4.4 × 0.9–1.2 cm, linear-lanceolate, membranous, apex acute, slightly concave, green to whitish green becoming clear upon maturity, central rib externally prominent; lip when distended 4.3–4.8 × 3.5–3.9 cm, long unguiculate, tubular, fused to the column along the margins from the base up to 2.6–3 cm long, slightly concave near the base, 3-lobed, completely white in both surfaces, apex reflexed, dorsal surface smooth, ventral surface with a penicillate callus at 2.5–2.7 cm from the base, with 5–7 transversal rows of imbricate and denticulate scales, 2.5–4.8 × 2.8–3 mm, continuous towards the apex by 10–12 rows of tuberculate papillae with 1–2.5 mm long, and near of the base of the midlobe becoming enlarged to form a suborbicular tuft of trichomes towards the apex; lateral lobes 1.7–1.9 × 0.8–1.2 cm, widely and obliquely rounded, overlapping above the column, entire margins, conspicuously reflexed and revolute; midlobe 8–12 × 6–8 mm, transversely oblong, entire margins, with a tuft of trichomes that covers almost surface; column 2.6 × 2.8 cm long, semi-cylindrical, slender, base attenuate, apex with two small membranous wings, ventral surface glabrous below 3-lobed stigma, rostellum prominent; anthers versatile, saddle-shaped; pollen in monads. Fruit not seen.

Etymology:— The epithet refers to the Brazilian Portuguese name capixaba , of indigenous origin, meaning fertile land and it is used to refer to people born in the State of Espirito Santo, and permitted by Article 23.2 of the International Code of Botanical Nomenclature ( McNeill et al. 2012).

Distribution and Habitat:— Vanilla capixaba is only known from the type and a few other specimens observed during the fieldwork. The species inhabits the Seasonally semideciduous forests by the Alto Serra da Roseira, in Alegre, state of Espírito Santo ( Figure 3 ), and is seemingly restricted to inselbergs at elevations of ca. 600 m elevation, where it grows as a hemiepiphytic.

In the Espírito Santo the Seasonal semideciduous forests is one of the most important types of native vegetation, especially in the southern and south of the state ( Assis et al. 2007). These forests have a smaller stature and lower basal area than common tropical rain forests and thorny species are often prominent. Ecological processes are strongly seasonal with the growth takes place during the wet season. There is a build up of leaf litter during the dry season because sunlight penetrates down to the forest floor and the decomposition ceases in the low relative humidity, and many species bloom synchronously at the transition between the dry and wet seasons whilst the trees are still leafless ( Pennington et al. 2000). This region is in fact a mosaic of Atlantic Forest fragments, inserted in a matrix anthropized by agricultural activities, primarily extensive beef cattle livestock and coffee plantations ( Couto et al. 2016b), with low representation of protected areas (Área de Relevante Interesse Ecológico Laerth Paiva Gama and Parque Estadual Cachoeira da Fumaça). However, these forest fragments enshrine a unique flora, with high levels of richness, endemism ( Couto et al. 2016a) and novelties for the flora of Espírito Santo ( Leme et al. 2010, Fraga & Kollmann 2010, Goldenberg et al. 2012, Kollmann & Peixoto 2013, Giaretta & Fraga 2014, Fraga et al. 2014, Fraga & Guimarães 2014, Chautems et al. 2015).

Conservation:— The new species is represented only by the type material that is restricted to an area where the forests are being replaced by pasture or managed forests; and no conservation unit exists in the area. In addition, to its apparent rarity, restricted distribution, and vulnerability to human activities, Vanilla capixaba is not protected and therefore it should be considered endangered. However, more information is needed to evaluate the true conservation status of the new species, and according to previous recommendations of IUCN, the new species is categorized under Data Deficient category [DD].

Additional specimens examined: — BRAZIL. Espirito Santo: Alegre, Alto Serra da Roseira, Floresta Estacional Semidecidual, 20°47’45.4”S and 41°31’33.7”W, 600 m, fl., 3 October 2008, Couto & Manhães 965 (MBML!).

Comments:— In the Vanilla planifolia group, 12 of the 16 species have a penicillate callus, connected with the apical callus by rows of papillae, as recorded here for V. capixaba . Moreover, 14 species show a column with ventral trichomes, but the new species presents a glabrous column as occur in Vanilla appendiculata Rolfe (178: 1895) and Vanilla labellopapillata Koch et al. (2013: 975) . It differs from those species by a tuft of trichomes that covers almost surface of the lip.

Among the species listed by Soto Arenas & Cribb (2010) in the Vanilla planifolia group, Vanilla capixaba resembles Vanilla dubia and Vanilla cristagalli , due to the margins and shape, and type of ornamentation of the lip. Both species have entire margins and a long-unguiculate lip with a ventral penicillate callus connected to an apical callus by rows of papillae becoming trichomes distally near the apex of the midlobe. V. capixaba differs in the size of sepals and petals, where the sepals are smaller and petals widest; the lip is smaller but the midlobe is larger with 10–12 rows of tuberculate papillae near the base becoming enlarged to form a suborbicular tuft of trichomes towards the apex that covers almost entirely the midlobe surface; the column is smaller and ventrally glabrous. In V. dubia the sepals and petals are bigger and the petals are thinner; the lip is bigger and the midlobe is smaller with 3–5 rows of tuberculate papillae near of the base tapering to form a cuneate tuft of trichomes towards the apex that covers partially the midlobe surface without touching the apex; the column is bigger and ventrally lanuginose surface. Finally, in V. cristagalli the sepals and petals are bigger and the petals thinner; the lip is bigger and the midlobe is very smaller with 5–7 rows of tuberculate papillae near of the base tapering to form a cuneate tuft of trichomes towards the apex that covers partially the midlobe surface without touching the apex; the column is bigger and ventral surface puberulent ( Table 1).

Vanilla capixaba is endemic to Atlantic Forest of the Espírito Santo state and V. dubia is restricted to the Atlantic Forest, distributed in the states of Espírito Santo, Rio de Janeiro and probably Minas Gerais ( Fraga 2002), they are fairly isolated from each other, and their geographic distribution does not overlap. In contrast, V. cristagalli is common in Amazonia, especially in the region of Alto Solimões.

Figures

FIGURE 1. Vanilla capixaba Fraga & D.R. Couto. A. Habit. B. Detail of the apex and adaxial surface of the leaf. C. Flower, front view. D. Dissected flower E. Detail of the apex and adaxial surface of the petal. F. Detail of the apex and abaxial surface of the lip. G. Lower view of column. H. Detail of apex of column with versatile anther, lower view. (Couto 1270).

FIGURE 2. Vegetation physiognomy and morphology of Vanilla capixaba Fraga & D.R. Couto (c–d) and Vanilla paulista Fraga & Pansarin (e–f). A. General view of the Tropical Semideciduous Forest and inselbergs of Alto Serra da Roseira, Alegre, Espírito Santo, Brazil. B. Vegetation physiognomy of the Tropical Semideciduous Forest. C. Flower of the Vanilla capixaba, front view. D. Detail of the lip apex of the Vanilla capixaba with rows of tuberculate papillae that covers almost entirely the midlobe surface. E. Flower of the Vanilla paulista, lateral view. F. Detail of the lip apex of the Vanilla paulista with rows of tuberculate papillae that covers the center of the midlobe surface. Photos: D.R. Couto (A–D), E.R. Pansarin (E–F).

FIGURE 3. Map showing the geographical distribution of Vanilla capixaba (black dot) and Vanilla paulista (black square) in the southeast of Brazil.