Scottmoria petalocostata Cornejo, 2025

Cornejo, Xavier & Prance, Ghillean T., 2025, Two new species of Scottmoria (Lecythidaceae) from western Ecuador and six new combinations in the genus, Phytotaxa 696 (3), pp. 253-261 : 257-260

2. Scottmoria petalocostata Cornejo , sp. nov. ( Figs. 3 , 4 )

New species of Scottmoria , the size, shape of leaf blades and number of lateral veins resemble those of S. antioquiensis (Dugand & Daniel) Cornejo in Vargas et al. (2024:172), however, S. petalocostata differs from the latter species by the triangular, valvate calyx lobes (vs. broadly ovate to hemiorbicular, imbricate in the lower half) and the four outer petals with a prominent costa along the lower half and slightly pustulate abaxially (vs. petals not costate and smooth abaxially).

Type: — ECUADOR. Carchi: San Marcos de los Coaiqueres and surrounding perhumid forest on trail Chical-Tobar Donoso , 1°06’ N 78°16’ W, 800 m, 8 Feb 1985 (fl), B. Øllgaard, J. Korning, K. Thomsen & T. Illum 57654 (holotype: NY-728178!; isotypes: AAU!, QCA-54434!) .

Tree to 30 m tall and 30 cm DBH, the bark and trunk unknown. Stems glabrous, lenticellate, the lenticels circular to elliptic. Leaves petiolate, the petioles shallowly channeled adaxially, rounded abaxially, hemispherical in cross section, 12–20 × 2–3 mm, lenticellate, glabrous; blades elliptic, 10–15 × 5.5–8 cm, chartaceous (dry), with abundant black punctations abaxially, the base broadly obtuse to rounded, revolute, the margins entire, the apex rounded to shortly acuminate; venation eucamptodromous towards base and brochidodromous towards apex, the midrib rather smooth, sulcate adaxially, prominent, more or less finely veined and with abundant dark short streaks abaxially, glabrous, the secondary veins in 7–12 pairs, impressed to prominulous adaxially, salient abaxially, the tertiary veins reticulate. Inflorescences axillary and terminal, a panicle on leafy branches, the rachis 5.5–14 cm × 4–8 mm at lower half, straight to slightly flexuose, lenticellate, glabrous; pedicels 5–8 × 3–5 mm, richly verruculose-lenticellate, glabrous, blackish (dry); floral bracts absent; flower buds dark purple (fresh). Flowers ca. 3 cm in diam. (fresh), ca. 2.5 cm in diam. (dry); hypanthium glabrous, densely pustulate or verruculose-lenticellate, truncate at summit, abruptly contracted onto pedicel at base, 2–3 mm long, inconspicuously articulate; calyx with 6 lobes, the lobes triangular, 3–4 × 2–3 mm (fresh), broadly divergent to patent at anthesis, pustulate or verruculose-lenticellate (fresh) abaxially, the margins entire, the bases valvate, arising from fused calyx rim; petals 6, broadly obovate to ± orbicular or broadly ovate, 1.5–2.3 × 1.3–2 cm, dark purple, the 4 outer petals somewhat pustulate abaxially and with a prominent costa along the lower half; androecial hood with three coils, ca. 1.3 cm across, yellow (fresh), inner cleft present; vestigial stamens on outside of coils; staminal ring with ca. 120 stamens, the filaments 0.5–1.5 mm long (fresh), clavate, the anthers ca. 0.5 mm long (fresh); the ovary summit slightly raised over hypanthium, surrounded by a prominent intrastaminal ring scar, ca. 0.3 mm high, with a shallow circular depression between intrastaminal ring scar and summit of ovary; the style arising ca. 2 × 1.5 mm, stout, distinguished from ovary summit, a stylar collar absent, the stigma pore transversely linear-oblong. Fruits and seeds not known.

Discussion: — Scottmoria petalocostata resembles S. antioquiensis that is restricted to the departments of Antioquia, Chocó and Cundinamarca, in Colombia, and the state of Mérida in NW Venezuela ( Mori and Prance 1990, Mori et al. 2015, Vargas et al. 2024). For differences, see the diagnosis. Furthermore, the other species in the genus are not known to have abaxially costate four outer petals.

Etymology: —The epithet petalocostata refers to the outer petals with a conspicuous prominent costa.

Common names: —Not recorded.

Habitat and distribution: —A canopy tree of mature wet forests, in well drained soils. Known from northwestern Ecuador at 800 m elevation. This new species may also occur in the department of Nariño, southwestern Colombia.

Phenology: — Flowers have been collected in February.

Conservation status: — Scottmoria petalocostata is only known from the type collection gathered in 1985 from a single locality, it is assigned here the provisional category of Critically Endangered (CR B2 a, b) following IUCN (2022) criteria.

After a full revision of the genus Scottmoria we have found that the following species placed in Eschweilera exhibit the morphological characters of Scottmoria and therefore need to be transferred to that genus. The defining characters are the androecial hood with three or four inner coils as seen in medial longitudinal section, a short, stout, cylindric style, and two kinds of seed covering: 1) a thin white sarcotesta over the entire or most of the mature seed that is infiltrated within testa or 2) a thin white sarcotesta present over the entire or most of the young seeds, this mostly dissolving at maturity and leaving sarcotesta remains mainly near to the funicular lateral arils, that are thick, yellow to white, mostly half I-beam shaped, with rubber-like texture and with overlapping ends on the seed; seeds with funicle forked at insertion point from apex of seed, the funicle apical branches soon anastomosing into an elongate filiform vascular bundle as long as the whole seed, that is longitudinally arranged on top of seed lateral crest, and the funicle fully surrounded by the lateral aril, inserted at the inner base of the fruit ( Vargas et al. 2024, Cornejo & Prance 2024).

Figures

FIGURE 3. Scottmoria petalocostata. The holotype, Øllgaard et al. 57654 (NY). Image courtesy by The New York Botanical Garden.

FIGURE 4. Scottmoria petalocostata. A. Rehydrated flower showing the calyx, androecial hood and two inner petals, lateral view; B. Longitudinal section of a flower bud preserved in alcohol, note the triple coil, lateral view; C. Four detached and rehydrated longitudinally costate and pustulate outer petals; D. Calyx, and extended androecial hood exhibiting inner side of ligule and staminal ring; E. Pedicel, calyx, and lower costate petals, lateral view (A–E, based on Øllgaard et al. 57654, QCA, the isotype). Photos by Xavier Cornejo.