Tournefortiopsis triflora D.Pérez & Alzate, 2023

Pérez, David & Alzate, Fernando, 2023, A new species of Tournefortiopsis (Guettardeae, Rubiaceae) from northern Colombia, Phytotaxa 609 (2), pp. 145-150 : 146-148

Tournefortiopsis triflora D.Pérez & Alzate , sp. nov. ( Figure 1 )

TYPE: — COLOMBIA. Antioquia: municipio de Sonsón, vereda Chaverras, vertiente de la quebrada “El padre Sánchez”, ascenso al cerro La Paloma , cerros al NE, 2900–3000 m a.s.l., 5°37’N, 75°16’W, 10 April 1994 (fl, fr), R. Callejas et al. 11139 (holotype: HUA-100854 !) .

Diagnosis: — Tournefortiopsis triflora differs from the remaining species of the genus by the simple dichasium inflorescence (vs. usually double scorpioid cyme). It is similar to T. sopkinii C.M. Taylor (2021: 260) but can be distinguished by its leaf blades with abaxially glabrous areoles (vs. whitened lanulose), calyx limb 4 or 5-lobed (vs. truncate to shallowly 4-lobed) and shorter peduncles 0.4–1 cm long (vs. 1.3–2.5 cm long).

Description: —Shrubs 2–3 m tall; stems terete, young branchlets densely strigulose to hirsutulous. Stipules interpetiolar, caducous, triangular, 5–9.1 × 2.1–3.6 mm, densely strigulose in both surfaces, acuminate at apex. Leaves opposite, decussate; petioles terete, 0.3–1 cm long, strigose to hirsute; blade 2.8–6.8 × 1.4–3 cm, elliptic to slightly ovate, acuminate with tip 5–7 mm long at apex, obtuse to cuneate at base, drying subcoriaceous, adaxially bullate, strigose on costa and secondary veins, indument caducous except on costa, abaxially strigose to hirsute on costa, secondary, tertiary veins and margins, on both surfaces glabrous on areoles; venation eucamptodromous, secondary veins 7–9 pairs, tertiary veins subparallel, quaternary venation irregularly reticulated on abaxial surface, not visible in adaxial surface; adaxially costa, secondary, and tertiary venation impressed, abaxially costa, secondary, and tertiary venation prominent and quaternary venation plane. Inflorescences axillary, simple dichasium, 3-flowered; peduncles 0.4–1.1 cm long, puberulent to sparsely strigulose toward apex, bracts ovate, acute at apex, 1.2–1.7 mm long, adaxially sparsely strigulose, abaxially mostly glabrous. Flowers subsessile or pedicellate, calyx and hypanthium 2.5–4 mm long, hypanthium turbinate, 1.5–2.5 mm long, sparsely strigulose; calyx limb 0.6–1.1 mm long, 4 or 5-lobed, lobes ovate, rounded, externally strigulose, internally sparsely strigulose toward the base; corolla tubular in bud, purple, externally tomentose to velutinous, internally glabrous, tube 11.9–13 mm long, lobes at anthesis not seen; anthers 5, shortly pedicellate, dorsifixed, oblong, inserted in corolla tube, ca. 4 mm long, sagittate; ovary 3-locular; style ca. 14 mm long, antrorse-pilosulous, dilated toward the base; stigma capitate, lobulate, ca. 1 mm long, ca. 0.7 mm diam. Fruit ellipsoid, ca. 5.1 x 3.1 mm, immature green; pyrene immature 3-locular, with 3 apical horns.

Etymology: —The specific epithet refers to its simple dichasium composed by three flowers.

Distribution and habitat: — Tournefortiopsis triflora is found on the western slopes of Colombian Central Cordillera, in the municipality of Sonsón ( Figure 2 ). Although in the herbarium label states that it grows at 2900 m, the location and elevation is not correct and could be georeferenced with the information provided by one of the original collectors. The species grows at 2500 m in humid forest and is found in the lower part of the village Chaverras, near the urban center.

Morphological affinities: —The new species is similar to Tournefortiopsis sopkinii (see diagnosis) and T. crassifolia (Standley ex Steyermark 1964: 51) C.M. Taylor & A.C. Berger (2021: 242) . It can be differentiated from the latter by their glabrous areoles on the abaxial surface of the leaf (versus variably pubescent in T. crassifolia ), and leaves and peduncles smaller. Table 1 summarizes the main differences between these three species.

Tournefortiopsis triflora is also similar to a species group characterized by their small leaves, such as T. deviana C.M. Taylor (2021: 255) and T. torrana (C.M. Taylor 2010: 356) C.M. Taylor (2021: 262) . From the former it can be distinguished by its adaxially bullate leaves (versus adaxially plane leaves in T. deviana ) and smaller peduncles, and from the latter by its strigose indumentum on vegetative structures (vs. mostly glabrous in T. torrana ) and by its lobed calyx (vs. truncate).

Preliminary conservation status: —The new species is only known from the type locality, and no further records have been found since its collection in 1994. Evaluating the preliminary conservation status, an area of occupancy (AOO) of 4 km 2 was obtained. It is more complicated if one considers that is a region where anthropogenic activities are present, including deforestation, mainly due to avocado cultivation. Tournefortiopsis triflora is categorized as “Critically Endangered” (CR) according to IUCN criteria B2ab(iii) ( IUCN 2012, 2022).

Figures

FIGURE 1. Tournefortiopsis triflora D. Perez & Alzate: A. Fertile branch. B. Stipule. C. Detail of the abaxial leaf surface. D. Dichasium. E. Calyx and hypanthium. F. Corolla bud in longitudinal section. G. Anthers. H. Style and stigma. I. Trilocular ovary in transversal section. Illustration by Cristina Pareja based on Callejas 11139 (HUA).

FIGURE 2. Distribution of Tournefortiopsis triflora.