Sciodaphyllum apiciflorum Jiménez-Mont. & Idárraga., 2025

Jiménez-Montoya, Jaider & Idárraga-Piedrahíta, Álvaro, 2025, Four new species of Sciodaphyllum (Araliaceae) from the Western Cordillera of the Andes in Colombia, Phytotaxa 708 (2), pp. 128-144 : 129-133

Sciodaphyllum apiciflorum Jiménez-Mont. & Idárraga. , sp. nov. ( Figs. 1–2 ).

Type: — COLOMBIA. Antioquia. Peque, vereda Romeral chamizo, finca las flores, 6º58’59.5” N, 75º58’05.3” W, elev. 2718 m, 14 February 2022 (bud, im. fr.), Á. Idárraga, A. Vasco, W. Testo, M. Sundue, F. Giraldo, S. Vega, S. Morris & U. Arango 8525 (holotype JAUM! [accession 95000]; isotypes BRIT!, HUA!, MO!) .

Diagnosis: — Sciodaphyllum apiciflorum differs from S. quindiuense ( Kunth 1821: 7) De Candolle (1830: 261) , the species it most closely resembles, in having inflorescences with two secondary axes (vs. one), the 16–26 ultimate inflorescence units (umbels) arranged toward the branch apex (vs. 33–73 umbels distributed along the distal 1/2 to 3/4), mealy or tomentose indument on the leaf blades (vs. glabrous or sericeous indument) comprising trichomes that are dendritic and very twisted (vs. uniseriate or branched).

Sarmentose shrub, 2–10 m high, well branched, terrestrial; branches 5.9–9.2 mm diam. in sicco, scattered lenticels up to 2 (–3) mm diam., circular (occasionally elliptic) and hemispherical. Plant with mealy to tomentose indument, abundant on young parts, glabrescent; trichomes 0.5–1.5 (–2) mm long, dendritic, very twisted, usually with a thick central strand, or highly branched, whitish or ferruginous. Leaves palmately compound, loosely arranged toward branchlet apices, mealy to tomentose indument; stipular ligule (2.3–) 3–5.7 cm long, oblong, occasionally deltate or triangular, apex obtuse, convex, and bifid, abaxially canaliculated or not, spherical lenticels toward the base, turning brown-black in vivo, caducous distally where it dries up early; petioles (10–) 12.3–16.2 cm long, terete, not thickened at either end, with lenticels sometimes up to 1 cm long, spherical or linear; leaflets 9–11, arranged in a single whorl, held horizontally or semi-pendulous; petiolules (1.2–) 1.7–3.2 (–3.7) cm long, similar in size to each other, canaliculate adaxially, not thickened at either end, with lenticels sometimes up to 1 cm long, spherical or linear; blades (5.3–) 8–15.5 × (1.5) 2–4.5 cm, elliptic to oblong, sometimes obovate, symmetrical, adaxially just with scattered trichomes; base acute and convex, margin entire, apex acute and acuminate, acumen (0.4–) 0.7–1.5 cm long; venation pinnate, prominulous adaxially and prominent abaxially; secondary veins (24–) 32–52, semicraspedodromous or slightly brochidodromous, irregularly spaced, adaxially impressed in vivo and prominulous in sicco, abaxially prominulous, intersecondary veins less than one per intercostal area; irregular reticulate tertiary fabric, adaxially impressed in vivo and prominulous in sicco, abaxially prominulous. Inflorescences terminal, erect, mealy indument, with circular and hemispherical lenticels less than 1 mm wide in each of the axis insertion points; primary axis 5.7–12.9 cm long, with just two terminal secondary axes, each 15.2–29.3 cm long, each subtended by a bract 1–2.8 × 1.1–1.5 cm, triangular or obovate, apex obtuse and rounded, caducous; peduncles 16–26 per each secondary axis, 1.1–1.5 cm long, expanding up to 1.8 cm long in fruit, grouped toward the apex of the secondary axes in the last 2–3 cm long, ebracteate or subtended by bracteoles 0.1–0.2 mm long, auriculate, apex rounded, persistent; ultimate inflorescence units forming umbels, pedicels (2–) 3–5 per unit, 6–9 mm long, expanding up to 11 mm in fruit, ebracteolate. Hypanthium (immature) 2–4 × 3–5 mm in sicco, mealy indument; calyx forming a truncate rim, 0.4–0.5 mm high, margin entire; corolla (immature) 1.5–2.2 × 4.4–5.2 mm, calyptrate, hemispheric, not fissured, mucronate, externally glabrous or sparsely covered with a mealy indument, internally glabrous, dark-garnet in vivo; stamens 8–9 (–10), filaments not seen, anthers (immature) 2–2.2 × 1–1.5 mm, reniform, oblong, dorsifixed, color not seen; ovary disc concave, 1–1.5 mm deep; styles (7–) 8–9, ca. 2 mm long, basally connate, distally free; carpels (7–) 8–9. Fruits (immature) drupaceous, (5–) 7–10 × (4–) 5–7 mm, obconic, cylindroid, covered with mealy indument; ovary disc 2–3 mm deep; persistent styles 4.5–6 mm long; pyrenes 6–7 × 3–4 mm, flattened laterally.

Distribution and habitat: — Sciodaphyllum apiciflorum is only known from one locality in the northern part of the Western Andean Cordillera, in the municipality of Peque, Antioquia ( Fig. 3 ). This species was found growing in well-preserved low montane humid forests (bh-MB; Holdridge 1971) at around 2700 m in elevation.

Phenology: —Specimens collected in February had floral buds and immature fruits, which does not allow us to infer with certainty its phenology, but the flowering and fruiting of this species probably occur throughout the year, as in many other species in the genus.

Etymology: —The epithet “ apiciflorum ” refers to the ultimate inflorescence units (umbels) arranged toward secondary axes apex.

Additional specimens examined (paratypes): —So far this species is only known from the type collection. In addition, two juvenile individuals were observed at the type locality.

Discussion: — Sciodaphyllum apiciflorum is characterized among other species of the genus, by the two secondary axes of the inflorescence that are disposed at the apex of the primary axis, and the umbels that are arranged toward the apex of the secondary axes.

This species belongs to the informal group Cotylanthes , which is based on the genus Cotylanthes Calestani (1905: 100) , now regarded as a synonym of Sciodaphyllum . This informal group is represented by perhaps a dozen species distributed between Costa Rica and northern Ecuador, with their largest representation in Colombia ( Frodin et al., 2010), and it is mainly characterized by the scandent or sarmentose shrubby habit, the inflorescences in single (or occasionally 2 or 4) secondary axes, the umbellate terminal inflorescence units, the calyptrate corolla, reniform anthers, and (5–)7–11 stamens, styles and carpels.

This new species resembles Sciodaphyllum quindiuense in its stipular ligules oblong, triangular and caducous, the generally elliptic leaflets blades, in the umbellate terminal inflorescence units, in its calyptrate corolla, 8–10 stamens and styles, ovary disc concave, and in the fruits obconic and cylindroid. Moreover, Sciodaphyllum quindiuense is endemic to Colombia, commonly recorded between 1500 and 2800 m of elevation throughout the Andean region, while S. apiciflorum is only known from the type locality.

Figures

FIGURE 1. Sciodaphyllum apiciflorum. A. Branch with leaves and inflorescence. B. Secondary axis of the inflorescence with a bract. C. Adaxial (left) and abaxial (right) surfaces of the leaflets with detail adaxially. D. Immature fruit. E. Stipular ligule in detail. F. Ultimate inflorescence units in buds. G. Bud with calyptra removed (top). A–G from Á. Idárraga et al. 8525. [Drawing by Diego Zapata Z.].

FIGURE 2. Sciodaphyllum apiciflorum. A. Branch with leaves and inflorescence. B. Secondary axis of the inflorescence with a bract. C. Adaxial surface of the blade. D. Abaxial surface of the blade. E. Stipular ligule. F. Ultimate inflorescence unit with buds. G. Ultimate inflorescence unit with immature fruits.A–G from Á. Idárraga et al. 8525. [Photographs by Á. Idárraga].

FIGURE 3. Distribution map of Sciodaphyllum apiciflorum, S. bracticonspicuum, S. monteblancense, and S. punctatum.