Schlegelia longirachis Aymard & M.A.Jaram., 2023

Aymard Corredor, Gerardo A. & Jaramillo, M. Alejandra, 2023, A new species of Schlegelia (Schlegeliaceae) from wet montane forest of Colombia and a key for the species of the genus, PhytoKeys 230, pp. 257-269 : 257

Schlegelia longirachis Aymard & M.A.Jaram. sp. nov.

Type.

Colombia. Boyacá. Municipio Otanche. Serranía de Las Quinchas, sector la Y, Finca Lote Terreno , 5°41'42.6"N, 74°19'37.5"W, 1200 m, 26 Oct 2022 (fl, fr). M. Alejandra Jaramillo, Andrés F. Majin-Ladino, Lucindo Galvis & estudiantes de Taxonomía vegetal 2022-1. (Holotype: COL!; Isotypes: UMNG-H!, HUA!). Figs 1 , 2 .

Schlegelia longirachis resembles S. monachinoi , but can be differentiated from this species by the longer internodes, 4-8cm long in S. longirachis , vs. 1.5-4.5cm in S. monachinoi . The leaf blades densely black punctuated on the adaxial surface, vs. sparsely punctuated towards the base of the blade on both surfaces in S. monachinoi . The inflorescences are longer 4-18 cm long in S. longirachis , vs. 3-11 cm in S. monachinoi . Bracts are oblong vs. lanceolate-triangular in S. monachinoi .

Description.

Root-climbing liana internodes 4-8 cm long, ca. 3cm in diameter, pale brown when dry, branches sparsely lenticelate. Leaves simple, opposite; petioles 12-20 mm long, glabrous; leaf blade lanceolate, lanceolate-elliptic, rarely oblanceolate, 4-22 × (3.2) 4.5-9 cm; coriaceous, densely black punctuated on the adaxial surface (Fig. 1C ), glabrescent or with simple trichomes located near base and in the midrib on the abaxial surface (Fig. 1B ), base obtuse-rounded or cuneate, apex rounded or acute, margins entire, black-brown upon drying; venation brochidodromous, midrib prominent on the abaxial surface, 6-7 pairs of secondary veins, the tertiary veins conspicuously reticulate on the abaxial surface. Inflorescence axillary, narrowly thyrsic with dichasial partial inflorescences; rachis puberulous to sparsely adpressed pubescent (5-12 cm long in flower, 12-18 cm long in fruit); flowers 14-20, produced in long-peduncled, 2-3-flowered dichasia along the rachis, each flower subtended by a bract and 2 bracteoles (Fig. 1D ), bracts 2-3 mm long, oblong, glabrous, ciliate at the margins; bracteoles ca. 1 mm long, triangular, ciliate at the margins; pedicels 3.5-4.5 mm in flower, 7.5-8.5 in fruit, adpressed pilose. Calyx cupular ca. 6 × 5 mm, bilabiate fused, 4-lobed, lobes oblong, 2-2.5 (3.2) mm long, apex rounded-acute, white, sparsely puberulent and with white disk-shape glands on the outer surface (visible in dry collections), glabrous and reticulate veined inside. Corolla campanulate-hypocrateriform with 5 reflexed lobes, white, deep pink at the throat (Fig. 2B ); tube 7-8 mm long, ca. 4 mm wide in the mouth; lobes 3-4 × 3 mm, glabrous inside, minutely puberulous outside. Stamens didynamous (Fig. 1H ), subexserted, filament 3-4 mm long, pilose at the base, inserted at ca. 4 mm from base of corolla; anthers ca. 1.5 mm long, oblong, glabrous; staminode absent. Pistil with conical ovary, ca. 1.5 × 1.5 mm, glabrous; nectariferous disk fused and not clearly differentiated from the ovary base. Fruit a berry, 6.6-8 mm in diam., spherical, drying black, glabrous with conspicuous papillae, covered to the middle by a persistent calyx (Fig. 1I , 2B ). Seeds not seen.

Phenology.

Collected in flower in March, and in flower and fruit in October.

Etymology.

The specific epithet refers to the long rachis of the inflorescences that is present in this new species. The long rachis of S. longirachis displays the flowers away from the foliage, a characteristic that may have some bearing on the pollination strategy of the species.

Distribution and habitat.

The species is known to occur in montane forest remnants between 1200 and 1900 m. In the type locality, S. longirachis grows in forest consisting of medium to tall trees.

Conservation status.

This species is known only from the type and two additional localities; however, it is reported here as a very rare species. It should be regarded as Endangered (EN) due to the low number of known localities, its estimated Area of Occupancy (AOO) of 12,000 km2, and its estimated Extent of Occurrence (EOO) of 755,768 km2 ( IUCN Standards and Petitions Committee 2022). Additionally, the conservation of these forests is at risk due the continuous deforestation and degradation of the “Serranía de Las Quinchas" and their surrounding areas on middle Magdalena river, and the Virolín Region ( Galindo-T. et al. 2003) especially in the years during the pre- and post-conflict period (peace agreement was signed in 2017). The expansion of deforestation, degradation and water pollution continues ( Salgado et al. 2022), with significantly greater agricultural use, pasture, selective logging, illicit crops and mining ( Restrepo et al. 2021). Although conservation status assessments can be made for species with such small numbers of collections ( Rivers et al. 2011), it may be difficult to assess whether the appearance of rarity in a species is due to the lack of, or outdated, data, or to its actual rarity ( Verspagen and Erkens 2022). Fortunately, the area where S. longirachis occurs is protected as part of the Regional Natural Park Serranía de las Quinchas ( Stiles and Bohórquez 2000; Bohorquez-Osorio et al. 2020) and Fauna and Flora Santuary Guanentá-Alto Rio Fonce ( Galindo-T. et al. 2003).

Additional specimens.

Colombia. Santander. Municipio de Charalá. Corregimiento de Virolín. Vereda El Reloj, Camino a Olival, aprox. 6°08'N, 73°20'W, 1680-1700 m, 03 Mar 1981, S. Díaz Piedrahita 2273 (COL); Municipio de Charalá, Virolín, Vereda Palmar, 6°03'44.8"N, 73°12'50.4"W, 1894 m, 06 Oct 2009, M. Blanco et al. 53 (COL).

Notes.

The species described here is morphologically similar to three taxa S. fuscata A. H. Gentry S. monachinoi Moldenke and S. parviflora as characterized in Table 1 . However, it is most similar to S. monachinoi from the Andean wet forests in Colombia, Ecuador and Venezuela ( Gentry 1977, 1982a, 2009). Both species have elongate, narrow axillary thyrses, the corolla and lobes lilac inside and fruit 0.5-2.5 cm in diam. S. longirachis differs from S. monachinoi in the characters presented in diagnosis. The new species can be distinguished with the key to the species presented below.

Figures

Figure 1. Schlegelia longirachis A a flowering branch B detail of the leaf abaxial surface C detail of the leaf adaxial surface showing the black punctations D inflorescence showing the bract and bracteoles E bract F calyx extended G corolla and adnate stamens extended H detail of a stamen I fruits. Illustration by Paola Pineros.

Figure 2. Schlegelia longirachis A a flowering branch B detail of the inflorescence. Photos by Andres Majin.