Colubrina amazonica W. Palacios, 2015

Palacios, Walter A., 2015, A new species of Colubrina (Rhamnaceae) of the Amazon region of Ecuador, Phytotaxa 224 (3), pp. 296-299 : 296-298

Colubrina amazonica W. Palacios , sp. nov. ( Fig. 1 )

The new species is similar to C. spinosa , but differs in its leaves which have 5–8 pairs of lateral veins and the basal concave glands elliptical, usually with the longer outer edge tangential to the leaf margin, the fascicle of sessile short-shoots with few nodes covered by overlapping bracteoles, together usually forming a globose mound and the individual short-shots not easily discernable.

Type:— ECUADOR, Sucumbíos:Quebrada Güepicillo, cuenca del Río Güepí, esquina noreste de Ecuador, Inventario Rápido, campamento 3, 00°10.38’W, 75°40.33’S, 220–276 m elev., October 2007, W. Palacios, N. Dávila, R. Foster, B. Alverson, C. Vriesendorp, J. López, L. C. Lucitante & S. Descante 16111 (holotype 209784 QCNE!, isotype F!).

Tree to 15 m tall. Young branches with elongated lenticels. Leaves simple, alternate, 10–18 × 4–8 cm, elliptical, less frequent oblong or obovate, membranaceous, glabrous or rarely with scattered hairs on the median nerve on the abaxial surface, 5–8 pairs of lateral veins, and two glands in the outer margin of the base of the blade on the abaxial surface, one to each side of midrib. The glands are elliptical, concave, with raised edges usually with the longer outer edge tangential to the leaf margin. The base of the leaflets is obtuse or acute, margins entire, apex broadly apiculate or acuminate, the tip as an extension of the midrib to form a tiny acumen or not, rarely retuse. Stipules 3–7 mm long, deciduous, lanceolate; petiole 0.8–1.3(–1.5) cm long. Inflorescence axillary or ramiflorous, sessile short-shoots with few nodes covered by overlapping bracteoles, together usually forming a globose mound and the individual short-shots not easily discernible, covered with dense hairs. Flowers 20–30 per fascicle, with scattered sinuous hairs; pedicels 0.5–1.2 cm long in flower, 1–1.8 cm long in fruit; hypanthium funnel-shaped, 1–1.5 mm long; sepals 5, ovate, 0.8–1.3 mm long; petals 5, induplicate, membranaceous, 0,7– 1.2 mm; stamens 5, incurved, covered by petals; disc an annular ring, flattened, glabrous; ovary broadly ovoid, glabrous. The fruit is a trilocular capsule, rounded or slightly triangular, smooth, 8–12 mm, dividing at maturity into 3 endocarpids, endocarpids separating irregularly under of a ventral line, the 2 septa and to some degree dorsally. The base of the septum is retained on a flattened hypanthium, forming a columnella with tree basal membranaceous wings. The seeds are one per endocarpid, 4–6 mm long, with the two inner sides flat-concave and the third side as wide as the other two and convex, brown-bright.

Etymology: —The name of the new species refers to the Amazon region of Ecuador where the species is found.

Distribution and habitat:— The new species has been described based on specimens of Amazon region of Ecuador, however, according Pool (pers. comm., 2015), at least two collections of Peru Amazon deposited MO, corresponding to the new species.

Etnobotany and vernacular names: —This species is called “oncatahue” (Waorani name) by the local inhabitants.

Phenology: —Flowering occurs mainly from August to November and fruits from December to April.

Specimens examined: — Sucumbíos: Cantón Shushufindi, Comunidad San Isla, 00°20’15”S, 76°20’01”W, E. Freire & I. Suárez 5050, 5065 ( MO, n.v, QCNE!) ; R. Bensman 307 (QCNE!); Comunidad de Santa Elena, 00°20’46”S, 76°33’14”W, 250 m, D. Reyes 230 ( MO, n.v, QCNE!). Napo: Estación Biológica Jatun Sacha , Río Napo , 8 km al E de Misahuallí, 01°04’S, 77 36 W, 450 m. R. Bensman 102 ( QCNE!) ; C. Cerón 6109, 6138, 6151, 7361 ( MO, n.v., QCNE!) ; C. Cerón & C. Iguago 5362, 5368, 5391, 5397, 5524, 5529, 5626, 5633 ( MO, n.v., QCNE!) ; C. Cerón, M. Crizón & C. Iguago 8750 ( MO, n.v., QCNE!) ; Carretera Campococha-Chontapunta, 00°55’S, 077°25’W, T. Núñez & G. Tapuy 661 ( MO). Orellana: Joya de los Sachas, Pompeya. Sendero hacia el Río Indillama a partir de la casa de S. Papa, 00°25’S 076°37’W, E. Gudiño & S. Papa 1918 ( MO) ; Cantón Orellana, Comuna Parutu Yacu, 15 este de Coca, Laguna Taracoa, 00°25’, S,76°50’, W, 240 m, D. Neill & W. Rojas 9983 ( MO, n.v., QCNE!) ; Parque Nacional Yasuní, vía Maxus , 00°35’S, 76°30 W, 230 m, D. Neill et al., 10288 ( MO, n.v., QCNE!) ; M. Aulestia et al., 2992 ( MO, n.v., QCNE!) ; M. Aulestia & N. Andi 648 ( MO, n.v., QCNE!) ; M. Aulestia, et al.,1200 ( MO, n.v., QCNE!) ; Dik 780 ( MO, n.v., QCA, QCNE!) ; J. Macía & C. Vélez 1925 ( QCNE!) ; B. Ollgaard et al.,57055 (QCNE!); N. Pitman & M. Aulestia 220 ( QCA!, QCNE!) ; F. Hurtado 3032 ( MO, n.v, QCNE!) ; K. Romoleroux & R. Foster 2493 ( MO) ; G. Villa et al. 148 (MO, n.v.); Carretera MAXUS km 3.5–3.9, 00°25’S, 76°37’W, E. Gudiño et al., 2105, 2295 ( MO) ; A. Grijalva et. al., 396, 400, 417 ( MO, QCNE) ; Tiputini, Biodiversity Station , 00°38’S, 076°10’W, N. Pitman & T. Delinks 2969 ( MO) ; Reserva Etnica Huaorani. Carretera y oleoducto de Maxus, Km 116+6, 01°03’S, 076°12’W, M. Aulestia y Bainca 3475 ( MO). Pastaza: Pozo Petrolero Namoyacu, 30 km al sur de Curaray, 76°57’ W, 01°40’S, 290 m, S. Espinoza y T. Coba 577 ( MO, n.v., QCNE!). According Pool (pers. comm., 2015) the specimens Ayala 2330 and 2361, both from Peru, Prov. Loreto, Dtto. Tigre, on Rio Corriente Forestales Shiviyacu , both in MO, appear to be this same species .

Discussion: — Liesner (1999) reported three species of Colubrina for Ecuador: C. arborescens , C. elliptica and C. spinosa . Subsequent analyses of voucher specimens at MO and CQA suggest different. For instance, collections such as Neill 6869 (MO) reported as C. elliptica , corresponds to C. arborescens ; while the collection of Cerón & Iguago 5397 (MO) reported as C. spinosa , corresponds to the new species described here. In addition, the sterile collection of Cerón & Yánez 59922 (MO, CQA!), could correspond to C. glandulosa var. glandulosa . Furthermore, the status of C. arborescens is unclear. This species is cultivated in the Coast, from where it was supposedly taken to the Amazonian region of Ecuador. It is locally known as caoba de Manabí, in honour of the Manabí Province, so some argue that it is in fact a species native to Ecuador. To facilitate identification of C. amazonica a comparative table including other Colubrina species found in Ecuador is presented below ( Table 1).

In her treatment of C. spinosa for Flora Mesoamericana, Pool (2015) studied several Ecuadorian specimens deposited at MO and cited above. Pool also concluded that some specimens were not C. spinosa and belong to an undescribed species. Colubrina amazonica is similar to C. spinosa , considered native to Central America and Mexico, in many characters: leaf (position, shape, size, pubescence and arrangement), inflorescence type (fascicled short-shoots, the short-shoots with nodes covered by over lapping bracteoles), flowers (size, nature of disc, annual ring not obscuring semi-inferior ovary) and fruits (size and nature, including presence of columnella) but differs in the leaves with 5–8 secondary veins, a pair of concave and elliptical glands usually with the longer outer edge tangential to the leaf margin and short-shoots of inflorescence with few nodes, together usually forming a globose mound and the individual short-shots not easily discernable. In contrast, C. spinosa has leaves with 8–12(–13) pairs of secondary veins, two fungiform (that is circular with strongly raised margin and depressed center) or globose glands, the glands attached basally to abaxial leaf and along part of circumference tangentially to leaf margin, and short-shoots of inflorescence with several to numerous nodes and individually discernable ( Pool 2015).

Figures

FIGURE 1. Colubrina amazonica: A. photograph of fresh (bar = 1 cm), B. pressed specimen (bar = 1 cm) and C. detail of glands on the abaxial leaf (bar = 2 mm). A and B material from Palacios 16111 et al. (F), isotype; C from Cerón et al 8750 (QCNE).