Vanilla rivasii Molineros, Rob.Gonzalez, Flanagan &amp; J.T.Otero, sp. nov.
Creators: name: Molineros-Hurtado, Francisco
name: Mina, Robert Tulio González
name: Flanagan, Nicola S.
name: Tupac Otero
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Asparagales
Orchidaceae
Vanilla
Vanilla rivasii

description: <i>Vanilla rivasii</i> Molineros, Rob.González, Flanagan &amp; J.T.Otero, <i>sp. nov.</i> TYPE: Colombia, Valle del Cauca, Buenaventura, Sendero El Paraíso, cultivated by A. Rivas, <i>R. T. Gonzalez 1118</i> (holotype, CUVC). FIGURES 1–2. Hemi-epiphytic <i>herb</i>. <i>Stems</i> dark green, 6.8-8.0 mm thick, terete, smooth, the internodes 8.0-9.3 cm long. Young aerial <i>roots</i> greenish to greyish, subterete to Fattened, 4.2 mm thick. <i>Leaf</i> shortly petiolate, the petiole <i>ca</i>. 10 mm long, blade oblanceolate, acuminate, the apex incurved, base subobtuse, the basal margin revolute, subcoriaceous, pale green with a central concavity, 16.5-24.6 × 4.0-5.5 cm. InForescence terminal, sometimes lateral with pale green rachis of 12-40 cm in length and 0.7 cm in thickness with white dots in the epidermis, a shortly pedunculate raceme, the rachis congested, with up to 150 Fowers, with bracts distant up to 6 mm. <i>Bracts</i> pale green, basal ones alternate distichal. <i>Distal bracts</i> ovate and concave, 3-4 × 5 mm. <i>Ovary</i> subterete to sub-trigonous, curved, pale green with white base and white dots in the epidemis, 45-55 mm length and 4.5 mm in diameter, white in the base and pale green in the rest. <i>Flowers</i> ephemeral with 2-4 open simultaneously, conspicuous with buds pale yellow at base, apex green, 10-12 cm diameter when spread out, aroma of rose and clover Fowers; sepals yellowish green outer, whitish yellow inside, basal surface of the lip yellow, mid lobe and throat yellow lined dark yellow-ochre; the segments spreading, strong rose fragrance. <i>Dorsal sepal</i> yellowish green, deeply recurved, long-lanceolate, narrow at the base, apex sub-acute and sub-calyptrate, with 13 veins, of equal length to lateral sepals, 68 × 8-10 mm. <i>Lateral sepals</i> directed downwards, long-lanceolate, subacute, base long attenuate, lateral sepals fused in the proximal third of the length; with 13-14 veins, very smooth, 67 × 8-11 mm. <i>Petals</i> pale yellow to cream, slightly recurved at the apex, narrowly elliptic-oblanceolate, obtuse, concave, narrower than the sepals, longitudinally keeled on the abaxial surface, the keel broad and conspicuous, 7-8 veins, 68 × 9 mm. <i>Lip</i> showy, 66 × 35 mm forming a long tube, marginally fused to the column at least 40-42 mm, with 30 veins; when spread out trilobed with the midlobe oblong, bilobulated, the lateral lobes well defined with rounded shoulders, overlapping above the column, oblong-triangular to sub-square, tapering at apex, with thickened axial cushion near the lip apex <i>ca.</i> 6 × 23 mm with 7-8 thickened keels with papilose texture extended to the lateral lobes. The margin of the lip is sub-entire and Fabellate; slightly verrucose at the base with brownish papillae, the apex somewhat narrowed and forming a cushion, the penicillate callus 4.5 × 6.0 mm covered by 4 yellow showy lacerate structures of scales thickened in the distal portion, separated 44 mm from the lip base. <i>Column</i> subterete, elongated 45.0-49.0 × 2.6 mm, yellow whitish, with brownish tricomes in the distal ventral part; membranous wings 5.3 mm; bilobed stigma with rectangular emergent lobes, 1.2 × 1.1 mm. <i>Anther</i> versatile, ovate, 3 × 2.6 mm. <i>Fruits</i> elongated, pale green, subtriangular with white dots in the epidermis. 130-180 × 11 mm, dehiscent when mature into two valves, with a strong vanilla aroma detectable over more than 200 m. PARATYPE: Colombia, Valle del Cauca, Buenaventura, Bahía Málaga. <i>N. H. Ospina 466</i> (CUVC). OTHER RECORDs: Colombia, Buenaventura, <i>Lehmann H.K.1185</i> (K, fruit!). <i>F. G.</i> DISTRIBUTION: Known only from the Pacific coastal region in the Valle del Cauca, and Chocó Departments, Colombia. The species has been observed occurring naturally in the wild in small isolated populations, mainly in regenerating secondary growth forest. Known populations comprise between one and twelve apparently separate plants. The largest population of twelve plants occurs over an area of 25 Ha. Localities have been identified up to 300 km apart. The association with secondary forest may be a consequence of sampling bias, as most exploration has been conducted close to populated regions. It is likely that, with further exploration of the Colombia Pacific region, particularly away from settlements along the coast, more populations will be found. The known localities will not be mentioned explicitly so as to protect the small populations of this species from the threat of collection from the wild. PHENOLOGY: No clear seasonality has been observed. Initiation of Fowering has been observed in the month of January, corresponding with a dryer climatic period in the region. However Fowering has continued until April, June, July and September, resulting in inForescences of up to 150 Fowers. Natural fertilization has been observed of 6-18 % of Fowers in an inForescence. EPONYMY: This species is dedicated to Luis Álvaro Rivas, a local farmer committed to sustainable agricultural practices and biodiversity preservation. The type specimen consists of the collection <i>R. T. Gonzalez 1118</i> from Buenaventura, and <i>N. H. Ospina 466</i> from Bahia Malaga, with pictures taken by F. Molineros-Hurtado. <i>Vanilla rivasii</i> Molineros-Hurtado, González, Flanagan &amp; Otero belongs within <i>Vanilla</i> subgenus <i>Xanata</i>. <i>Vanilla rivasii</i> has affinity to the <i>V. hostmannii</i> group, possessing the thickened veins in the lip apex and the distichous arrangement of the basal bracts of the inForescence characteristic of this group. <i>Vanilla rivasii</i> may be distinguished from the other <i>Vanilla</i> species in the group by the frequent terminal position of the inForescence, although occasionally this can be lateral. The bracts of the inForescence are smaller than those of related species such as <i>V. cribbiana</i> Soto-Arenas, <i>V. ruiziana</i> Klotzsch, and the sympatric <i>V. dressleri</i> Soto-Arenas. Flowers are larger, with deeply recurved sepals. The lateral sepals are fused in the basal third. The mid-lobe of the labellum is conspicuously bilobulated with a thickened axial cushion near the apex bearing 7-8 thickened veins with papilose texture extending into the lateral lobes. <i>Vanilla rivasii</i> is morphologically most similar to <i>V. cribbiana</i> but differs from this species in the fused lateral sepals in the basal third, the bi-lobed shape of the central lobe of the labellum and the greater number of thickened veins. <i>Vanilla rivasii</i> differs from the sympatric species <i>V. dressleri</i> in the tri-lobed labellum and non-granulose sepals. Additionally, the living Fower of <i>V. rivasii</i> has much less conspicuous orange longitudinal stripes on the labellum than those of <i>V. dressleri</i>. <i>Vanilla rivasii</i> is more heliophytic than <i>V. dressleri</i>, with subcoriaceous, deep green, smooth leaves. It differs from <i>V. ruiziana</i> from Peru and Bolivia which has an ovate mid lobe of the lip, and 1-3 thickened veins on the lip apex. <i>Vanilla rivasii</i> plants have been documented with terminal inForescences producing up to 150 Fowers (less in lateral inForescences), compared with a maximum recorded for <i>V. hostmannii</i> of 60, and for <i>V. cribbiana</i>, and <i>V. dressleri</i> of ca. 10, and rarely up to 30 Fowers. Mature fruits are dehiscent.
description: Published as part of <i>Francisco Molineros-Hurtado, Robert Tulio González Mina, Nicola S. Flanagan &amp; Tupac Otero, 2014, VANILLA RIVASII (ORCHIDACEAE), A NEW SPECIES FROM THE COLOMBIAN PACIFIC REGION, pp. 352-358 in LANKESTERIANA 13 (3)</i> on pages 354-356, DOI: 10.5281/zenodo.344790