Salacia juradoi Cornejo & Lombardi, 2021

Cornejo, Xavier & Lombardi, Julio A., 2021, Salacia juradoi (Celastraceae), a new species from coastal Ecuador, Phytotaxa 524 (2), pp. 125-130 : 128-129

Salacia juradoi Cornejo & Lombardi , sp. nov. ( Fig. 1 ).

Salacia juradoi is a new species from coastal Ecuador that resembles S. impressifolia (Miers.) A. C. Sm. , but differs by the opposite to decussate arrangement of leaves, larger leaf blades, narrowly oblong to oblong, sometimes narrowly-lanceolate, 14–30 cm (versus elliptic, rarely ovate, obovate or lanceolate, [3.4–] 10–14.2 cm), margin with scattered dark-brown marginal glands (vs. eglandular), flower buds oblate, light-green, white-pulverulent (versus globose, ferrugineous), margin of sepals often ciliate or ciliolate (vs. glabrate), petals patent, erose (vs. deflexed, entire), outer margin of disk entire (vs. fimbriate), and fruit with pericarp smooth (vs. verrucose).

Type: — ECUADOR. Guayas: Guayaquil , top of cerro 507, 2º09’ S 79º59’ W, 450 m, 5 Dec 2020 (fl), X. Cornejo & J . Josse 9359 (Holotype: GUAY!) .

Shrubby tree to small tree 2–4(–5) m tall, to 20 cm DBH, bark rugose, with age becoming longitudinally and irregularly fisurate. Branches frequently horizontally arranged, often more or less curved down, subcylindric, the terminal branchlets gray to grayish-green or the youngest full green, somewhat complanate, sometimes flexuose, minutely lenticellate, glabrous. Stipules deltoid to broadly deltoid, minutely ciliolate, soon deciduous, interpetiolar stipular scars present. Leaves opposite and decussate, sometimes subopposite, the blade coriaceous (in vivo), stiffly chartaceous (dry), usually narrowly-oblong, sometimes oblong-lanceolate or narrowly-lanceolate, 14–30 × 2.5–6 cm, the length (3.5–)4 to 6(–6.5) times the width, the base broadly cuneate to subcordate, the margin entire, thickened, with scattered dark-brown marginal glands, the apex acute to narrowly obtuse, the adaxial side of blade deep- or olive-green, smooth, somewhat glossy, the midrib moderately prominent to impressed, yellowish to greenish for most of the length (in vivo), the blade green, smooth to subbullate, somewhat glossy (dry), the abaxial side paler green, opaque (in vivo and dry), the midrib prominent, with 7–11 secondary nerves on each side, adaxially impressed to slightly sulcate, abaxially more or less prominent (dry), glabrous, the tertiaries inconspicuous; petioles 7–16 mm long, articulate to branch, subcylindric, thick, more or less flattened adaxially, inconspicuously rimulose, yellowish to brownish or yellowishgreen (in vivo), shallowly channelled adaxially and yellowish to gray (dry), grabrous. Inflorescences fasciculate, 1–4 flowers, axillary and ramiflorous; bracts inconspicuous, more or less deltoid, erose-ciliolate, reddish-brown; pedicels 10–18 mm long, light-green, white-pulverulent. Flower buds oblate, light-green, white-pulverulent. Flowers 12–15 mm diam at anthesis, rotate; sepals deltoid to hemiorbicular, 1–2.5 × 2–3 mm, margin often ciliate or ciliolate, lightgreen, white-pulverulent; petals suborbicular or hemiorbicular to orbicular-obovate, 4–7 × 4–7 mm, patent at anthesis, margin erose, revolute, light-green to yellowish or light-orange, glabrous; disc patelliform, 3–5 × 1–1.5 mm, lightgreen, the outer margin thin, light-green, cream, red to maroon or black, glabrous; stamens 1.7–2.5 mm long, filaments linear-triangular, 1–2 mm long, flattened, usually light-green, sometimes light-brown, anthers cordate, 0.5–1.0 mm long, 2-locular, yellow to orange; ovary 1–2 mm diam., 3-lobed, light-green, style 0.8–1.5 mm long, light-green, stigma not differentiated, light-green or dark-brown. Fruit berry, globose, 5–6 × 4.5–5.5 cm (in vivo), green-pruinose turning to orange at maturity, epicarp coriaceous, 2–3 mm thick (in vivo), smooth, minutely lenticellate, pedicel stout, richly lenticellate; pulp slimy, translucent, scarce; seeds oblong-elliptic, 1.8–2.5 × 1–1.5 cm, surrounded by a fleshy pulp derived sarcotesta, embryo cream.

Etymology: —The epithet honors Eduardo Jurado-Peralta (9 September 1969 – 18 January 2021), an Ecuadorian businessman, cultural manager, and a music promoter in the city of Guayaquil, a nature lover and long-time friend of the first author, who recently passed away by Covid.

Vernacular names: —Pomarosa de montaña (Clark et al. 1540, MO, QCNE); pomarosa de monte (Neill & Nuñez 10458, MO, QCNE).

Habitat and distribution: — Salacia juradoi occurs on limestone rocky soils located at the narrower and altitudinally lower southeastern tip of the cordillera Chongón-Colonche, that is an extra-Andean coastal arc surrounded by highly disturbed lowland dry forests; that mountain range end up on the western side of the city of Guayaquil in coastal Ecuador ( Bonifaz & Cornejo 2004). Over 300 masl the habitats of Chongón-Colonche turn somewhat moister refreshed by winds and cooled by microdroplets of seasonal mist ( Fig. 2 : A; op. cit.). The new species is restricted to secondary and mostly conserved fragments of forests often with a closed canopy between 300 to 450 masl ( Fig. 2 : B); for 28 years has not been observed to colonize in full sun at open cut areas nearby (Cornejo, pers. obs. in the field). The relative age of those limestone rocky soils named as San Eduardo formation where S. juradoi occurs is Middle Eocene, Lutecian to Bartonian (47.8 to 37.8 MY), those soils contain macrofossils, calcareous algae, planktonic and benthic foraminifera ( Moreira, 2019). The fossil evidence suggests that those soils were shallowly sumersed as a reef within an open marine environment, and that emerged as a consequence of a colission of coastal Ecuador against the western Andean margin most likely during or posteriorly to the latest Oligocene-Miocene (ca. 28.1 to 20.4 MY) ( Jaillard et al. 1995). The new uplifted lands from Proto-Chongon-Colonche cordillera were islands that allowed the colonization most likely initially by mangrove trees that contributed at some extend on salt removal from new soils and simultaneously generating a top of organic ground, as they still do today just 3 to 5 km south from the type locality, forming new soils and subsequently allowing the settlement of terra firme species and ecosystems ( Wolf 1892). It is here hypothesized that spatial isolation and environmental changes drove the process of plant speciation in Proto-Chongon-Colonche islands allowing the formation of the only known population of S. juradoi , and other local and regional endemics. The berries of S. juradoi are among the largest indehicent fleshy fruits of native species in the type locality, as trees as Capparidastrum petiolare (Kunth) Hutch. (Capparaceae) , and Gustavia angustifolia Benth. (Lecythidaceae) , and vines of Curcurbita ecuadorensis H.C. Cutler & Whitaker ( Cucurbitaceae ) ( Belletini 2018, Cornejo obs. pers.), all of those relatively large-fruited species are dispersed by extant vertebrates and share a similar pattern of distribution that is endemic to the Pacific deciduous dry forests located in western Ecuador to northwestern Peru.

Phenology: —Flowering from October through December, fruiting from late December through March.

Conservation status: —The populations of Salacia juradoi occur within fragments of forests that encompasses an area of less than 75 km 2, that is ecologically isolated and restricted to the seasonally moister slopes and upper parts of Cerro Blanco which forms an interconnected continuum with Cerro Azul and the nearby Cerro 507, all covered by a Pacific dry deciduous seasonal native vegetation ( Fig. 2 ). Those hills are private forests protected by the Cemento Nacional and ESPOL University that are under steady pressure by mining for cement and the expansion of urban frontier of the city of Guayaquil. Therefore, the preliminary status of EN B2 ab(iii) ( IUCN 2017) is assigned to this new species.

Figures

FIGURE 1. Salacia juradoi Cornejo & Lombardi. A, Terminal branchlet with petioles and leaf bases, adaxial view; B, A leafy ramiflorous branch, abaxial view; C, Light-orange matureflowers and flower buds; D, Light-green mature flowers from a same population; E, Immature fruit; F, Mature fruit. Photographs taken from the holotype, X. Cornejo 9359 (GUAY).

FIGURE 2. Habitat of Salacia juradoi Cornejo & Lombardi. A, Cerro Azul hill located west from Guayaquil, note the horizontal precipitation as a white layer of condensation adding moisture at the top of the hill; B, Top of Cerro 507 hill, the type locality. Photos taken on August 2020 (A) and December 2020 (B), during dry season.