Cedrela angusticarpa W. Palacios, 2023

Palacios, Walter A., Torres, Maria De Lourdes, Quintana, Martina Albuja, Asadobay, Pacarina, Iglesias, Juan, Quillupangui, Richard, Rojas, Estefania, Santiana, Janeth, Sola, Augusto & Rivas-Torres, Gonzalo, 2023, A new species and a new record for Cedrela (Meliaceae, Sapindales) in Ecuador: morphological, molecular, and distribution evidence, Phytotaxa 595 (2), pp. 127-138 : 131-135

Cedrela angusticarpa W. Palacios , sp. nov. ( Figures 1 & 2 ).

Type:— ECUADOR. Esmeraldas: Quinindé, Rosa Zárate, Reserva FCAT, El Descanso , 513 m, 0°22’N, 79°40’W, 23 January 2022, fl., few old fruits attached to the branches, W. Palacios, F. Castillo & J. Olivo 18755 (holotype: QCNE 260031 - leaves and inflorescence; QCNE 260032 - leaves and fruits, isotype: MO).

Diagnosis: — Cedrela angusticarpa is related to C. odorata . The distinctive characteristics of these species are: a) leaflets oblong to oblong-lanceolate, base obtuse or rounded, (8–)9–15 × (4–)5–6 (–7) cm in C. angusticarpa vs leaflets oblong, oblong-falcate, base usually strongly asymmetric and rounded on one side, acute or obtuse on the other, 7–14 × 2.5–4 cm in C. odorata ; b) inflorescence a robust-erect panicle, 40–70 cm long in C.angusticarpa vs a curved panicle, 15–40 cm long in C. odorata ; c) calyx with five teeth in C. angusticarpa vs calyx 2–3-lobed in C. odorata ; d) fruits narrowly obovoid, 1.3–1.8 cm in diameter, base acute, sometimes slightly 5-angled when dry in C. angusticarpa vs fruits oblong or ellipsoid, 1.8–2.6 cm in diameter, base rounded or obtuse in C. odorata .

Trees up to 30 m high; young branches 0.8–1.1 cm in diameter, glabrous, with circular or elliptic, scattered lenticels; young buds puberulent, covered by ovate scales 0.4–0.6 mm long. Leaves paripinnate, 45–70 (75) cm long; petiole 9–15 cm long, terete, glabrous, lenticellate; rachis 30–70(–80) cm long, terete, glabrous, lenticellate. Leaflets (6–)8– 10(–13) pairs, (8–)9–15 × (4–)5–6 (–7) cm, opposite or sub-opposite, oblong, oblong-lanceolate, rarely slightly falcate, coriaceous, glabrous or with very short and scattered trichomes, shinning above; apex acuminate; base rounded, symmetric or, less frequently, with a slightly uneven side; venation eucamptodromous; secondary veins 9–14 pairs, parallel to each other and curved towards the margin; intersecondary veins absent or inconspicuous, or only present between few pairs of secondary veins; tertiary veins inconspicuous or not visible to the naked eye; petiolules 3–5 mm long, terete. Inflorescence is a broadly pyramidal panicle, 40–70 cm long, curved; lateral branches up to ca. 35 cm long; peduncle and rachis lenticellate, glabrous. Flowers 8–9 mm long; pedicel 0.8–1 mm long; calyx cyathiform, 2–2.3 mm long, puberulent, 5-dentate, teeth ovate with acute apex, symmetric, 0.8–1.1 mm long, with obtuse or rounded apex; petals 5, oblong, oblong-spatulate or oblong-lanceolate, 7–7.5 × 1.8–2.1 mm, adnate to androgynophore in the lower half, moderately puberulent inside, densely puberulent outside; stamens (free portion) 1.9–2.1 mm long, glabrous; ovary broadly ovoid, glabrous, style with thick discoid head. Capsule narrowly obovoid and tapering towards the base, apex rounded, base acute, sometimes slightly 5-angulated in dry condition, 3.5–5.5 × 1.4–1.8 cm in diameter, with scattered lenticels; valves 0.7–1.1 cm wide. Seeds 3–3.5 cm long.

Flowering and fruiting period: —Flowering occurs in the dry season, between July and September. The fruits are mature about seven months after flowering.

Distribution and habitat: — Cedrela angusticarpa is restricted to the foothill forests of the western Andes Mountain Range of northern Ecuador, between 550 and 1300m in elevation mainly between the cantons of San Miguel de los Bancos and Santo Domingo, along the Las Mercedes road and in the mountains of Mache (canton Quinindé) between 400 and 700 m.

As a result of the climatic modeling, it was observed that C. angusticarpa shows a relatively small potential distribution area in the provinces of Pichincha, Santo Domingo de los Tsachilas, and Esmeraldas.Within this distribution, some individuals of this species can also be recorded in grasslands as part of the tree vegetation that farmers leave as shade or to keep individuals for high-quality wood provision ( Figure 3 ).

Etymology: —The specific epithet refers to the narrow fruits recorded in this taxon, although the length is equivalent to that of other species.

Conservation status of Cedrela angusticarpa : —Endemic to Ecuador. The modeled geographic distribution showed that the species’ habitat has been lost by ~80% due to the expansion of agricultural and livestock frontiers. As mentioned before, where found, most of C. angusticarpa individuals are growing in secondary forests. Calculated Extent of Occurrence (EOO) resulted in 1,607.06 km ², and the area of occupancy (AOO) was calculated to be 36 km ² for this species. Due to the habitat loss and its restricted distribution, and using IUCN Categories and Criteria (2019), the species should be considered as Critically Endangered (CR A2cd). This conclusion is validated by W. Palacios, Meliaceae specialist for Ecuador.

Field characteristics: — Cedrela angusticarpa is a tree that reaches up to 30 m in height and ca. 1.6 m in dbh. Adult trees have rough or superficially cracked bark ( Fig. 2A ). In open places, the crown is wide, rounded, and dense (i.e. many leaflets and leaves), with a dark green color.

Common names and local uses:—Local name: “cedro”. Farmers of the Santo Domingo and San Miguel de los Bancos use this species as wood provision (for building houses) and as cattle shading. On the other hand, in the mountains of Mache, where it seems that the populations were more abundant, between 1995 and 2005, the peasants sold the adult trees to merchants who, in turn, sold the wood in the national market.

Taxonomic relationships:—Vegetatively, C. angusticarpa is close to C. odorata L. The taxonomic differences between these species are detailed in the diagnosis. At this point, one must remember that Pennington & Muellner (2010) indicate that C. odorata may be treated as a compound of species that include three taxonomic entities, one of which occurs in Ecuador and Guyanas. This observation was corroborated by Cavers et al. (2013), who used several molecular markers for phylogenetic analyses of Cedrela , with an emphasis on C. odorata . Using internal transcribed spacer (ITS) sequence data obtained from a large sample of C. odorata from Central and South America and the Caribbean, and following the work done by Pennington & Muellner (2010), Cavers et al. (2013) identified 22 haplotypes, four of them corresponding to specimens from the coast of Ecuador, which formed a clade with C. montana Moritz ex Turczaninow (1858: 415) and C. angustifolia DC. (1824: 624) , both of which are montane species. Despite having a close genetic affinity with these two montane species, most of the specimens analyzed by Cavers et al. (2013) were obtained from trees showing a clear C. odorata morphology. One of the specimens (Perez et al. 3255, QCA 133167) cited by Cavers et al. (2013) as belonging to C. odorata was analyzed here and placed under C. angusticarpa .

Specimens examined: — ECUADOR. Esmeraldas: Quinindé, Santa Isabel, Refugio del Gavilán , REMACH, 541 m, 648298W, 41878N, 27 August 2020, Palacios et al. 18745 ( QCNE) ; January 2023, Palacios et al. 18831, 18832 ( QCNE) . Pichincha: San Miguel de Los Bancos, vía principal a Quito, cerca del sector Solaya , aprox. 5 km antes de Los Bancos, 1100 m, 1180, 0°01’33’’N, 78°51’34’’O, 5 Jun 2019, Palacios 18435, 18445 ( QCNE) . Los Bancos-Las Mercedes , 605 m, 0°10’03’’S, 79°05’13’’W, 18 March 2007, Pérez et al. 3255 ( QCA) . Vía a Santo Domingo , sector 23 de June, potreros, 1191, 0°1’16’’S, 78°53’09’’W, 7 April 2019, Palacios et al. 18406 ( QCNE) . San Miguel de Los Bancos, sector Nuevo Amanecer , 857 m, 0°2’36’’S, 78°57’37’’W, 4 April 2019, Palacios et al. 18407 ( QCNE) . Vía a Santo Domingo , entre Mulaute y Las Mercedes, 698 m, 0°07’09’’S, 79°0’15’’W, 13 June 2018, Palacios et al. 18408 ( QCNE) . Santo Domingo de los Tsáchilas: vía a Santo Domingo, sector Las Mercedes , 751 m, 0°10’44’’S, 79°01’50’’W, 6 June 2018, Palacios et al. 18466 ( QCNE) ; sector río Achotillo , potreros, 581 m, 0°08’58’’S, 79°05’09’’W, 7 June 2018, Palacios et al. 18412, 18413, 18414 ( QCNE).

Molecular evidence supporting the differentiation of C. angusticarpa from C. odorata :—The PCoA, based on nine microsatellite loci, produced a two-dimensional plot for the first two principal coordinates ( Figure 4 ), which accounted for 42.9% of the data variation. The samples of C. angusticarpa clearly formed their own genetic cluster when compared to C. odorata populations located in the Coast and Amazon regions in Ecuador, suggesting that they belong to a new, separate species.

Figures

FIGURE 1. Cedrela angusticarpa: Branch with inflorescences. W. Palacios et al. 18445. Photograph by W. Palacios.

FIGURE 2. Cedrela angusticarpa: A. bark of an adult tree, B. lower surface leaflets (scale bar = 6 cm), C. lower surface leaflets (scale bar = 2.5 cm), D. flower (scale bar = 0.4 cm), E. cymule of inflorescence (scale bar = 1 cm), F. old fruit.A. W. Palacios et al. 18407; B, C, W. Palacios et al. 18413; D, E, W. Palacios 18445; F, W. Palacios 18755. All photographs by W. Palacios.

FIGURE 3. Map detailing the potential distribution and locations of individuals used for climatic niche modeling of C. angusticarpa and C. kuelapensis in continental Ecuador. Peru is located to the south and Colombia to the north of Continental Ecuador defined in this map.

FIGURE 4. Principal Coordinate Analysis (PCoA) for sampled individuals of C. angusticarpa and C. odorata for the first two principal coordinates, which explain 42.9% of the variation in the data. Samples from C. angusticarpa (green) clearly segregate from samples of C. odorata from the Coast (red) and Amazon (blue) regions.