Eschweilera silverstonei Cornejo, 2023

Cornejo, Xavier, 2023, Eschweilera brevipetiolata and E. silverstonei: Two new species of Lecythidaceae from western Colombia, Phytotaxa 585 (4), pp. 287-292 : 290-292

Eschweilera silverstonei Cornejo , sp. nov. ( Fig. 2 )

This new species of Eschweilera is similar to E. integrifolia but differs by the more developed, paniculate-pyramidal, multiflorous, terminal inflorescences that are ca. 10 cm long (vs. ramiflorous, mostly unbranched, shortly racemose, pauciflorous, and up to ca. 4.5 cm long), and greenish-yellow flowers (vs. purple to creamish-white).

Type: — COLOMBIA. Valle del Cauca: Bajo Calima; Consesión Pulpapel / Buenaventura , 3°55’ N 77°00’ W, ca. 100 m, 9 Aug 1984 (fl), M. Monsalve 214 (holotype: CUVC-19929!; isotype; NY-02152729!) .

Tree ca. 5 m tall, the trunk and bark unknown. Stems glabrous, sparsely lenticellate. Leaves: shortly petiolate, the petioles shallowly channeled adaxially, rounded abaxially, hemispherical in cross section, 8–13 mm long, ca. 3 mm diam., glabrous or glabrescent; blades oblong-elliptic, 20–25 × 5–7 cm, chartaceous, with abundant brown punctations abaxially, the base obtuse to rounded, the margins entire, the apex acuminate; venation eucamptodromous towards base, brochidodromous towards apex, without conspicuous marginal veins, the midrib flat adaxially, prominent abaxially, glabrous or nearly so, the secondary veins in 13–16 pairs, slightly prominent on both sides, the tertiary veins reticulate. Inflorescences terminal, pyramidal-paniculate, the rachis ca. 4 cm long, ± straight, glabrescent, lenticellate with age; pedicels 5–6 x 2–3 mm, tapered to articulation, lenticellate, puberulous, drying blackish. Flowers ca. 3 cm diam.; hypanthium glabrous, truncate at summit; calyx with 6 lobes, the lobes triangular to deltoid, 3–4 x 2.5–3.5 mm, ascendant at anthesis, smooth (dry) abaxially, the bases barely imbricate, arising from fused calyx rim; petals suborbicular to ± oblong 1.5–2 x 1–1.5 cm, greenish white; androecial hood with three coils, ca. 1.5 cm wide, greenish white; vestigial stamens on outside of coils; staminal ring with ca. 300 stamens, the filaments 0.3–0.5 mm long (dry), clavate, the anthers ca. 0.5 mm long (dry); the ovary summit slightly raised over hypanthium, the style ca. 1 mm long, distinguished from ovary summit, stylar collar present. Fruits, seeds, and arils not known.

Discussion: — Eschweilera silverstonei resembles E. integrifolia but differs from the latter species by the more developed, paniculate-pyramidal, terminal, multiflorous inflorescences (bearing over 30 flowers each), that are ca. 10 cm long (vs. ramiflorous, mostly unbranched, shortly racemose, pauciflorous inflorescences (bearing up to 4 flowers each), that are up to 4.5 cm long, and greenish-yellow flowers (vs. purple to creamish-white). This statement is based on the numerous field observations of E. integrifolia in the type locality and several additional places where this species occurs in western Ecuador.

Etymology: —The epithet honors Phillip Silverstone-Sopkin (1939–2018), who studied the taxonomy of Amaryllidaceae and was an enthusiastic researcher of the Colombian flora. He was the former Director of the CUVC herbarium at the Universidad del Valle in the city of Cali, Colombia.

Common names: —Guascanato (Monsalve 214).

Habitat and distribution: — An understory tree of mature, wet to pluvial forest in non-flooded areas. It is known only from western Colombia in the Bajo Calima area , in the department of Valle del Cauca, at ca. 100 m elevation .

Phenology: — Flowers have been collected in August.

Conservation status: — Eschweilera silverstonei occurs in the Bajo Calima area. Although the status of its populations is not currently known, due to the absence of new collections for over three decades, we suggest that this new species be assigned the IUCN conservation status of near threatened (NT) ( IUCN, 2022).

Paratypes: —Known only from the type collection.

Figures

FIGURE 2. Eschweilera silverstonei.A. Terminal inflorescence with detached flower buds; B. Flower bud; C. Calyx and style emerging at center; D. Flower with detached petals showing the androecial hood and stamens; E. Lateral view of a longitudinal section of androecial hood showing three coils; F. Branch with leaves, a terminal inflorescence, and detached flower buds to the right. (A–F, based on Monsalve 214, the type). Photos A–F, by Xavier Cornejo.