Rinorea chiribiquetensis Hoyos-Gómez, 2024

Hoyos-Gómez, Saúl E., Callejas Posada, Ricardo & Wahlert, Gregory A., 2024, Seven new species of Rinorea (Violaceae) from the Neotropics, PhytoKeys 242, pp. 241-271 : 241-271

3. Rinorea chiribiquetensis Hoyos-Gómez sp. nov.

Type.

Colombia. Dept. Caquetá: alrededores del refugio la Selva , 1 ° 4 ' 0.23 " N, 72 ° 44 ' 24.6 " W, 630 m elev., 1 Dec 1992, M. Velayos et al. 6509 (holotype: MO [acc. 4644279 ; barcode MO- 1590549 ]!; isotypes: COL!, MA [cat. 543845 ]!) .

Description.

Rinorea chiribiquetensis is similar to R. ovalifolia (Britton) S. F. Blake by the lamina base symmetrical, margin subserrate, ovary globose and style filiform, but it differs by the smaller lamina, 3.2–7.2 × 1.6–3.6 cm, with appressed pubescence on the abaxial surface and domatia present (vs. the larger lamina, 3–16 × 2–7.5 cm, glabrescent and lacking domatia in R. ovalifolia ), shorter inflorescence, 1.5–5 cm long (vs. longer inflorescence, 4–12 cm long), shorter pedicels, 1.7–3.3 mm long (vs. longer pedicels, 4–6 mm long) and stamens with filaments free (vs. stamens with filaments fused).

Shrubs to 1.5 m tall, terminal branchlets pubescent with appressed golden trichomes 0.3 mm long, lenticels 0.5–0.6 mm. Leaves opposite, petiolate; petiole 3–6 mm long, pubescent with erect golden trichomes 0.2–0.3 mm long; stipules deciduous, free, lanceolate 1.9–2.1 × 0.9–1 mm, pubescent with appressed golden trichomes 0.2 mm long, margin entire; lamina elliptic, 3.2–7.2 × 1.6–3.6 cm, adaxially pubescent on mid-vein with appressed golden trichomes 0.2–0.3 mm long, abaxially pubescence on mid-vein, secondary and tertiary veins with appressed golden trichomes 0.2–0.3 mm long; with 5–6 major secondary vein pairs, semi-craspedodromous; secondary veins with irregular spacing, and veins angle smoothly decreasing proximally between them; symmetrical base, cuneate, margin subserrate, apex acuminate, acumen 5–6 mm long, mucronate, leaf domatia present. Inflorescence axillary, lateral or terminal, racemose, 1.5–5 cm long, 0.5–1 cm diam., axis pubescent with erect golden trichomes 0.2 mm long; pedicels 1.7–3.3 mm long, articulated near the middle, pubescent with erect golden trichomes 0.2 mm long,; bractlets persistent below articulation, subopposite, ca. 1 × 1 mm, herbaceous, costa pubescent with appressed golden trichomes 0.2 mm long, 3–5 veins; peduncle bracts deciduous, narrowly triangular 1–1.4 × 1–1.5 mm, herbaceous, pubescent with appressed golden trichomes 0.2 mm long, 3–5 veins, margin ciliolate. Flowers 3.2–3.5 × 3–3.3 mm; sepals subequal in size and shape, triangular, 1.5–1.7 × 1.7–1.9 mm, 5–7 veined, costa pubescent with appressed golden trichomes 0.2 mm long, margin ciliolate, apex apiculate; petals lanceolate, 3–3.3 × 1.4–1.6 mm, pubescent with erect golden trichomes 0.2 mm long near the apex, margin entire, apex acute; stamens 2.6–3 mm long, filaments free, 0.7–0.9 mm, dorsal gland glabrous, completely covering the filament; anthers elliptic, 1–1.1 × 0.3–0.5 mm, glabrous, apex rounded, connective 0.6–0.7 mm long, dorsal connective scale lanceolate, 2.2–2.4 × 0.8–1 mm, scarious, margin subentire, brown-orange; ovary globose, 0.7–0.8 × 0.8–0.9 mm, pubescent with appressed golden trichomes 0.4 mm long; style erect, filiform, 1.7–2 × ca. 0.1 mm, glabrous, stigma acute. Fruit unknown. (Fig. 5 )

Distribution and habitat.

Rinorea chiribiquetensis is endemic to Caquetá Department, Colombia, an area belonging to the Biogeographical Province of Imerí in the Boreal Brazilian Dominion (sensu Morrone (2014)). It occurs in lowland tropical rainforest from rocky substrates at an elevation of 630 m. (Fig. 6 )

Etymology.

Rinorea chiribiquetensis is named for the Chiribiquete National Park in Colombia.

Phenology.

The species is only known from one flowering specimen collected in December.

Conservation status.

The region encompassing the vast and remote Chiribiquete National Park is relatively little explored as evidenced by the scarcity of collections in the Tropicos database (https://www.tropicos.org; accessed 25 February 2023), GBIF (https://www.gbif.org; accessed 25 February 2023) and other Colombian Herbaria (e. g. COAH, COL, HUA). There are insufficient data to assess the risk of extinction of Rinorea chiribiquetensis and, therefore, the species is preliminarily assigned to the IUCN (2012) category of “ Data Deficient ” [ DD].

Notes.

Rinorea chiribiquetensis is sympatric with R. macrocarpa , but it can be differentiated by the presence of domatia (vs. domatia absent in R. macrocarpa ), smaller lamina, 3.2–4.2 × 1.6–3.6 cm (vs. larger lamina, 5.5–21.5 × 2–9.2 cm), filaments free (vs. filaments fused into a tube) and style filiform (vs. style conical). Rinorea chiribiquetensis can be differentiated from R. stevensii by the smaller lamina, 3.2–4.2 × 1.6–3.6 cm (vs. larger lamina, 4–12.5 × 2.5–7 cm in R. stevensii ) and less dense pubescence on the abaxial lamina surface, with trichomes 0.2–0.3 mm long (vs. denser pubescence on the lamina, with trichomes 0.4–0.5 mm long).

Figures

Figure 5. Rinorea chiribiquetensis Hoyos-Gómez A habit B detail of young twig with pubescence C detail of young twig showing lenticels D detail of leaf showing pubescence, adaxial surface E detail of leaf showing domatia, abaxial surface F leaf architecture G infructescence H flower I sepals, abaxial surface J petals, abaxial surface K gynoecium L stamens, showing adaxial and abaxial surfaces, with a detail of the dorsal gland (left). (A – L: M. Velayos 6509 [MO)].

Figure 6. Distribution of Rinorea chiribiquetensis (circle), R. ovalifolia (triangles), R. stevensii (stars).