Stenospermation albifoliumCastaño-Rubiano, sp. nov. TYPE: COLOMBIA. Depto. Caldas.Munic. Samaná, corregimiento de Florencia, PNN Selva de Florencia, vereda San Lucas, Río San Lucas, cascada cerca de la casa de Evangelista, 5° 30’ 02.3’’ N, 75° 03’ 06.7’’ W, 1203 m s.m., 4-VII-2021 (fl.), N. Castaño-Rubiano 2354 (holotype FAUC-39055!; isotype COL!). Figs. 1, 2, 3.Diagnosis.Similar to S. glaucophyllum Croat & D.C. Bay by its whitish leaves beneath, but differs in lacking an evident layer of white wax, sheath truncate on one side, semiacute on the other and entire margin (vs. rounded on one side, acute on the other and scarious margin), spathe meeting on the peduncle at an obtuse angle (vs. spathe meeting on the peduncle at an acute angle), and spadix slightly tapered toward the apex (vs. cylindric and rounded at the apex).
Description. Terrestrial herb, 1.5 m tall. Stem with internodes30-60 mm long × 16-20 mm diam., glossy when fresh, 11-44 mm long, 8-11 mm diam.; cataphylls not observed. Leaves erect; petioles 16-20 × 0.4-0.6 cm diam. when fresh, 11-19 cm long × 0.25-0.40 mm; geniculum concolorous, 15-40 mm long, 2.4-3.6 mm diam; sheath 10-15 × 0.5-0.8 cm, covering (58-)75-87% of the petiole in regular blades, 100% on those subtending the spadix, apex truncate on one side, semiacute on the other, entire margin; blades18-26 × 8-13 cm, elliptic, one side broader than the other, obtuse at base, acuminate at apex, coriaceous; upper surfaceglossy, dark green, drying olive-green; lower surface somewhat glossy, pale green to white, drying light green to whitish; midribsunken, paler than blade above, U-shaped below; primary lateral veins slightly conspicuous on the upper surface, conspicuous on the lower surface, about 30-40 per side, slightly arched, starting from an angle of 45-50°; tertiary veins less prominent than primary lateral veins, on both surface marginal bandnarrow 1.0-1.5 mm, bent towards the underside. 512DARWINIANA, nueva serie 11(2): 507-520. 2023Inflorescences erect; peduncles 23-24 cm long × 0.5 cm diam. when fresh, (11-)19-20 cm long × 0.22-0.33 cm diam; spathes 11 cm long × 3.2 cm width., papyraceus, naviculiform, meeting on the peduncle at an obtuse angle, immature spathe green, mature white, shiny, long attenuated at the apex, deciduous; stipe 2.0 cm long, 0.5 cm diam. when fresh, 1.0-1.5 cm long, 0.2-0.21 cm diam.; spadix 5 cm long, 0.13 cm diam. when fresh, 5-5.1 cm long, 0.90-0.91 mm diam. white, slightly tapered toward the apex when flowering, becoming capitate before fruit development. Flowers 0.18-0.21(-0.4) cm long × 0.1-0.16(-0.26) cm broad × 0.3-0.38 cm wide, four flowers visible in the primary spiral and 5-8 in the alternate spiral, one locule evident, hexagonal; stigma 1-1.5(-1.8) mm in the major diam.; stamens 1.1-1.8 mm long × 0.5-0.8 mm wide, hyaline, no divaricated, basifixed. Berries not observed.Etymology.The epithet refers to the whitish color on the adaxial blade surface.Distribution and habitat.This species is only known from the Central Andes in the Department of Caldas, in the National Natural Park Selva de Florencia in corregimiento de Florencia (Samaná), on forest edges close to vereda San Lucas. The elevational range of the species is between 1200 and 1400 m a.s.l.Phenology.Specimens were found flowering in July and August.