Eschweilera donosoensis Batista & S. A. Mori, 2017

Batista, Juvenal E. & Mori, Scott A., 2017, Two New Species of Eschweilera (Lecythidaceae) from rainforest on the Caribbean slope of Panama, Phytotaxa 296 (1), pp. 41-52 : 43-46

Eschweilera donosoensis Batista & S. A. Mori , sp. nov. ( Figs. 1–3 )

Eschweilera donosoensis differs from other Central American species of Eschweilera by its scalloped outer bark surface, flesh-colored inner bark; leaf blades medium-sized (3.2–19.7 × 1.5–8.4 cm), tapered from hypanthium to articulation, olive-colored; inflorescences not branched; flowers with pedicel/hypanthium 6–7 mm long (vs. 10–15 mm in E. hondurensis ), calyx-lobes not imbricate, thick, carinate toward base, 4.5–6 × 3–4 mm, petals white, androecial hood 2-coiled, yellow; fruits turbinate to cup-shaped with woody calyx-lobes persisting; seeds plane on 1 or 2 sides, the other sides hemispherical, aril lateral, splitting at chalazal end into 2–3 branches (vs. arils not branched in E. hondurensis ).

Type: — PANAMA. Colón, Distrito de Donoso, Botija , 8°50’12” N 80°38’41” W, 117 m, 19 Mayo 2015, J. Batista, C. Rodríguez, I. Vergara, & J. De Gracia 1368 (holotype, PMA!; isotypes, MO!, NY!, UCH!, SCZ!) .

Understory to subcanopy trees 7–20 (–25) m tall × 19.2–25 cm, buttresses <1 m tall. Bark dark-brown, scalloped, lenticellate, the outer bark thinner than inner bark ( Fig. 1 ). Leaves: petioles 3–9 mm long, canaliculate adaxially; blades elliptic, 3.2–19.7 × 1.5–8.4 cm, chartaceous, glabrous, with inconspicuous reddish punctuations abaxially (visible with hand lens) the base obtuse to rounded, the margins entire to crenulate, the apex acuminate to attenuate; secondary veins in 8–12 pairs ( Fig. 1 ), plane adaxially. Inflorescences from branches below leaves (ramiflorous), axillary, or terminal (suprafoliar), unbranched, the rachis 1–6 cm long, puberulous (at flowering), glabrous (at fruiting), sparsely lenticellate; pedicel/hypanthium 6–7 mm long., slightly tapered to articulation, puberulous, sparsely lenticellate. Flowers 2–4 cm diam.; bract ovate-triangular, 1.5–2 mm long, bracteoles elliptic, 3–3.5 mm long, deciduous, hypanthium puberulous, tapered to articulation; six calyx lobes, ovate, 4.5–6 × 3–4 mm, not imbricate, carinate at the base, horizontally oriented at anthesis, six petals, white or pale yellow, 15–28 × 12–14 mm, the ligule yellow, 15–25 mm long, androecial hood yellow, double coiled ( Fig. 2 ), ovary 2-locular, 6 ovules per locule. Fruits turbinate to cup-shaped, 3.5–5.7 (including operculum) × 3–6 cm. diam., 8–10 mm thick, calyx-lobes persistent, woody, supracalycine zone 7–10 mm wide, convex, infracalycine zone 18–39 mm wide, tapered to base, lenticellate, operculum 1–1.3 × 3–3.5 cm diam., slightly umbonate, sometimes convex. Seeds 2–4 per fruit, globose, plane on 1–2 sides, hemispherical on other sides, 2 × 1.4 cm, aril lateral, splitting at chalazal end into 2–3 branches, white ( Fig. 3 ).

Etymology:— The specific epithet of E. donosoensis is derived from the type locality in the Donoso District of Panama where it is common.

Distribution:—This species has only been collected from the Caribbean slopes of Donoso district, Colon province ( Fig. 7 ).

Habitat and Ecology:—Understory to subcanopy trees of lowland mature and late secondary rainforest at 100– 350 meters above sea level. It is an abundant tree in the MPSA concession and adjacent areas ( Fig. 8B ).

Phenology:—Flowers collected from February to September and sometimes in December. Fruits collected in February, May to July, September, and December.

Conservation Status: — Eschweilera donosoensis known from collections at PMA, MO and NY, comprising three general localities: Botija, Valle Grande and other sites in The Minera Panama Mining concession and a single collection (Holdridge 6249) outside of the Copper Mine concession in Donoso District, Colon Province. Based on the IUCN (2001) criteria this species is considered: Endangered (EN), with EOO: 369 Km 2, AOO: 40 Km 2, [EN B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v)]. The mining activity and indigenous settlements are fragmented into large-scale Donoso forest, this forest is not protected by the government of Panama.

Discussion: — E. donosoensis belongs to the E. parvifolia clade. Additional information and images of these species can be viewed on the Lecythidaceae Pages ( Mori et al., 2010) by consulting the following collections: E. donosoensis ( Batista G. et al. 1396, 1268).

This species is an endemic species, commonly found in the lowlands rainforests of the Caribbean slopes, specifically in Donoso district, Colón province; is most similar to another lowland rainforest species, Eschweilera hondurensis Standl (1940:318) which has larger leaves of 12–21 × 4–7 cm (vs. 3.2–19.7 × 1.5–8.4 cm); a longer pedicel/hypanthium of 10–15 mm long (vs. 6–7 mm long); calyx-lobes, imbricate at base, not carinate (vs. not imbricate, carinate at base); fruits cup-shaped to depressed globose and pericarp thin-walled 1–2 mm thick (vs. turbinate-shaped and pericarp thick-walled 8–10 mm thick); seeds with a lateral aril, not splitting at chalazal end (vs. aril splitting at the chalazal end into 2–3 branches).

E. donosoensis can be confused with Eschweilera pittieri R. Knuth (1939:93) , but in E. pittieri the calyx lobes are strongly imbricate, widely ovate in the flowers; in the fruits, the calyx lobes are very woody, and seeds with unbranched lateral arils not splitting at the chalazal end (vs. the calyx lobes not imbricate, slightly ovate in the flowers; in the fruits the calyx lobes are slightly woody in E. donosoensis ). These species mentioned above, belongs to the E. parvifolia clade according to Huang et al. (2015), see introduction.

Based on field and herbarium studies made by the first author during recent years, we now consider the Donoso lowland rainforest to be one of the sites with the highest number of Eschweilera in Central America.

Additional specimens examined (Paratypes):— PANAMA. Distrito de Donoso, Colón, Camp Botija on Quebrada Daniele and Rio Botija, SW corner of Donoso District , 8°50’N, 80°50’W, 60 to 150 m, 9-14 May 1968, L. Holdridge 6249 ( PMA) ; Área de construcción de helipuerto, en Petaquilla, 15 km del campamento de Colina, ( Parcela 2) P07095 , 8°49’N, 80°35’W, 15 Sep 2007, De Sedas 429 ( PMA) ; Teck Cominco Petaquilla mining concession. Ridgetop forest along road, 08°49’28”N, 080°39’29”W, 190 m, 21 Sep 2007, G. McPherson 19771 ( MO, PMA) ; 08°49’23”N, 080°39’35”W, 278 m, 23 Sep 2007, G. McPherson 19799 ( MO, PMA) ; Forest on slope. 08°49’08”N, 080°37’14”W, 100 m, 10 Dec 2007, G. McPherson & H. van der Werff 20062 ( MO, PMA) ; 08°49’44”N, 080°40’28”W, 300 m, 22 Feb 2008, G. McPherson & M. Merello 20145 ( MO, PMA) ; 08°49’33”N, 080°40’11”W, 300 m, 24 Feb 2008, McPherson & Merello 20221 ( MO, PMA) ; Colina Camp. Forested slopes along road, 08°49’23”N, 080°39’32”W, 101 m, 26 Feb 2008, M. Merello 3066 ( MO, PMA) ; Camp Colina. Forests along Quebrada Colina , 08°49’50”N, 080°39’30”W, 152 m, 3 Mar 2008, M. Merello 3202 ( MO, PMA) ; Forest near helipad, 08°50’05”N, 080°38’48”W, 140 m, 20 Jun 2008, McPherson 20548 ( MO, PMA) ; Forest near helipad H21 , 08°49’55”N, 080°38’11”W, 150 m, 27 Jun 2008, M. McPherson 20697 ( MO, PMA) ; Site of proposed copper mine ( MPSA), Forested slopes, 08°51’08”N, 080°38’38”W, 140 m, 9 Dec 2009, G. McPherson & M. Merello 21237 ( MO, PMA) ; Site of proposed copper mine ( MPSA). Forested slopes, 08°48’27”N, 080°36’20”W, 100 m, 13 Dec 2009, G. McPherson & M. Merello 21294 ( MO, PMA) ; Valle Grande, Sierra 18, sendero CABO, 8°50’05”N, 80°40’43”W, 315 m, 9 Dec 2014, C. Ramos & L. Rojas 387 ( MO, NY, PMA) ; Botija , 8°50’12”N, 80°38’41”W, 117 m, 5 Jul 2015, Batista et al. 1396 ( NY, PMA) ; Botija, sendero detrás de vivero. Bosque secundario, 8°49’41.9”N, 80°39’25”W, 131 m, 5 Sep 2015, J. Batista & E. González 1405 ( NY, PMA, SCZ, UCH) ; Entrada de Sedimentation Pond 5, área adyacente a Presa Este de Relave , 8°51’31.7”N, 80°38’40.9”W, 110 m, 12 Dic 2015, J. Batista & S. Forero 1499 ( MO, NY, PMA, SCZ, UCH) ; Entrada de Sedimentation Pond 5, área adyacente a Presa Este de Relave , 8°51’31.7”N, 80°38’40.9”W, 110 m, 8 Feb 2016, J. Batista & C. Rodríguez 1528 ( MO, NY, PMA, SCZ, UCH, US).

Figures

FIGURE 1. Eschweilera donosoensis. A. Bark showing slight depressions where irregular plates were shed (= scallops), thin outer bark, and reddish inner bark. B. Relatively small buttresses. C. Leaf blades showing adaxial surface. D. Leaf blades showing abaxial surface. Vouchered by Batista et al 1368. Photos by J. Batista.

FIGURE 2. Eschweilera donosoensis. A. Apical view of a flower. B. Basal view of a flower showing the non-imbricate, carinate calyx-lobes. C. Unbranched inflorescence in bud. D. Medial longitudinal section of androecial hood showing the first and second coils. Vouchered by Batista et al 1368. Photos by J. Batista.

FIGURE 3. Eschweilera donosoensis. A. Lateral view of a nearly mature fruit showing the persistent, woody calyx-lobes. B. Lateral view of immature fruit. C. Artificially opened fruit showing seeds with a lateral aril splitting at the chalazal end into 2–3 branches, the numbers represent the branches of the aril. D. Seeds showing lateral white aril. Vouchered by Batista et al. 1396. Photos by J. Batista.

FIGURE 7. Distribution of Eschweilera donosoensis and Eschweilera rotundicarpa. In blue the population of E. donosoensis from Donoso District, Colón Province. In red the population of E. rotundicarpa from General de División Omar Torrijos H. National Park, Coclé Province and Valle Grande, Donoso District, Colón Province.

FIGURE 8. Habitat of Eschweilera donosoensis and Eschweilera rotundicarpa. A. Cloud forest from General de División Omar Torrijos H. National Park, Coclé Province. B. Lowland rainforest from Donoso District, Colón Province. Photos by J. Batista.