Gesneria radiata J.L.Clark & Cinea, 2023

Gesneria radiata J.L.Clark & Cinea View in CoL , sp. nov. TYPE: HAITI. Departement du Sud : Massif de la Hotte , Parc National Pic Macaya , Bwa Formon, in rak bwa on hills in vicinity of village Formon, 18 1991199N, 74 0094199W, 986 m, 13 Jan 2015, J.L. Clark, W. Cinea, I. Henrys, M. Despagne & M. Sturla 14465 (holotype: US!; isotypes: MT! NY! SEL!).

Differs from all other congeners by the presence of uniformly white radially symmetrical corollas and an obligate lithophytic habit.

Lithophytic stout herb with erect shoots, up to 10 cm tall, rarely branched at base; stems suffrutescent, brownish red. Leaves alternate; petioles 0.2–0.4 cm long, light green; blades oblanceolate to obovate, 2.5–3.5 cm long, 1.0– 1.5 cm wide, coriaceous, base rounded, apex acute, margin with 3–5 serrations clustered near apex; adaxial surface shiny green, glabrous, abaxial surface light green, glabrous, secondary venation suppressed when live, more prominent when dry. Inflorescence reduced to single axillary flowers; remnant old flowers persistent at base, 1–3 mature flowers near apex; peduncles 3–5 mm long with a pair of reduced bracts subtending pedicels; pedicels nodding during anthesis and erect with mature fruits, with five elongate prominent wings that initiate ca. 5 mm above base, becoming prominent near apex, 1.6 cm long, green. Flowers protandrous; calyx lobes 5, equal in size and shape, uniformly light green, 13–16 mm long, 10–15 mm wide at base, apex acute, margin entire, spreading to truncate at anthesis; corolla truncate and nearly radially symmetrical, lobes fused in a shallow tube, upper lobes slightly fused at base, other lobes nearly free, uniformly white, each lobe 4–5 mm wide at the base, 4–6 mm long, margins of corolla lobes with small pilose trichomes. Androecium with filaments 2.5–3.5 mm long, white, glabrous, adnate for ca. 1 mm at base of corolla tube; 4 oblong free anthers, ca. 2 mm long, 1.5–2.0 mm wide; staminode not observed; pollen yellow; ovary inferior; disc and gynoecium not observed. Fruit a bivalved capsule, subglobose to avoid, splitting broadly and cup-shaped, 7–10 mm long, 6–9 mm wide, with persistant calyx lobes. Seeds numerous, reddish-brown, 0.4–0.8 mm, fusiform to subglobose, spirally striate.

Additional Specimens Examined — Haiti. — DEPARTMENT SUD: Massif de la Hotte, Parc National Pic Macaya, Forested area near Ville Formon. Broad-leaved wet forest on exposed limestone referred to locally as “rak bwa,” 957 m, 18 1991799N, 74 093299W, 14 Jan 2015, J.L. Clark, W. Cinea & M. Sturla 14491 (MO, MT, NY, SEL, US).

Distribution and Habitat — Gesneria radiata is an obligate lithophyte that is endemic to the Massif de la Hotte in Southwest Haiti. It is located on exposed vertical limestone in shaded forests referred to locally as “rak bwa” near the village of Ville Formon, ca. 950–1000 m. This rare species was only observed in two adjacent populations throughout three expeditions to the region.

Etymology —The name of this species refers to its radially symmetrical flowers.

Conservation — Gesneria radiata is geographically limited to two adjacent populations on the lower slopes of Pic Macaya. The high rates of deforestation throughout Haiti and recent increase in human activities inside the park are factors that risk the remaining extant forest. Therefore, this new species is likely to be categorized as Critically Endangered (CR) according to the IUCN Red List criteria ( IUCN 2012, 2019) for restricted geographic range (B1 a,b,c 1 B2 a,b,c).