Type. Colombia, Caqueta; Florencia, corregimiento el Caraño, vereda Sucre, 01°47'50.8"N, 75°38'50.5"W, 1020 m elev., 25 Oct 2020 [fr], F. Hoyos & W. Trujillo 046 (Holotype COL, Isotype COAH, UMNG, HUAZ, HUA) Diagnosis. Piper nokaidoyitau W. Trujillo & M. A. Jaram., can be separated from the similar species P. hostmannianum (Miq.) C. DC. (1869:287), by its prophylls up to 2.4 cm long, leaves 12–20 cm long vs. prophylls 2.8–3.5 cm long, leaves 21–26 cm long in P. hostmannianum. Description. Shrub up to 3 m tall; internodes (2.5–)3–4.5 cm long, canaliculate superficially, green, glabrous. Prophylls 2.8–3.2 cm long, green, glabrous, caducous, swollen in the basal portion (observable in live plants). Petioles uniform in size along all nodes, (0.7–)1–1.2(–1.5) cm long, sheathing at the base, smooth, glabrous. Leaf-blades coriaceous, drying black, uniform in shape and size along all axes, (4.5– )5–8 × (18) 21–26 cm, ovate, asymmetric, base rounded, glabrous on both surfaces, eciliate; pinnately nerved throughout, 4–5 ascending nerves on each side, eucamptodromous, with spacing decreasing and angle increasing towards the base, tertiary veins random, reticulate; apex acuminate. Inflorescences simple spikes, erect; peduncle 1–1.5 cm long, glabrous, green; rachis (7.5)10–12 × 0.3 cm in flower, 11–13 × 0.4– 0.5 cm in fruit, flowers densely grouped along the rachis, forming bands around the spike. Floral bracts cucullate, heart-shaped from above, 0.2–0.35 × 0.4–0.7 mm, glabrous centrally on the abaxial surface, margin densely fimbriate. Flowers with three stamens, filaments 0.3–0.5 mm long, anthers 0.1–0.25 × 0.2–0.3 mm, transversally dehiscent, dithecous, with connective not protruding, glabrate, idioblasts not evident, colour black when dried; stigmas 3, 0.1–0.25 mm long, sessile. Fruits obpyriform in side view and triangular from above, green when alive, black when dry, 0.5–0.7 × 0.8– 0.9 mm, glabrous, partially immersed in the rachis, with stigmas sessile and persistent. Distribution and habitat. Piper nokaidoyitau is known from the lower montane forests in the eastern slopes of the Andes in Colombia, ca. 1,100 m elevation (Fig. 2), the Department of Caquetá. It is a shade-loving species that grows in the understorey of preserved forest. Phenology. Flowering specimens were collected in September and October. Fruiting specimens in October. Etymology. Piper nokaidoyitau is named after the Huitoto name for Piper plants, “Nokaido yitau”. It means “the powers of the toucan” because these are sacred and medicinal plants used against fever, body and headaches and as anti-inflammatories. Phylogenetic relationships. Piper nokaidoyitau belongs to the Radula clade of Neotropical Piper (Jaramillo et al. 2008). Specifically, P. nokaidoyitau is sister to the Isophyllon subclade, within Radula. Isophyllon species are mostly self-standing shrubs with coriaceous leaves, pinnately nerved, acute or obtuse bases and flowers densely arranged in erect inflorescences. Isophyllon species occur in the Atlantic Forest, Central America and the Amazon Region. Conservation status. This species is known from four specimen collections representing two subpopulations. The locations where it occurs are threatened by deforestation and expansion of the agriculture frontier. The area of occupancy (AOO) of 8 km2 is small, which, together with the continuing decline in habitat quality, suggests it is Endangered [EN B1a+B2a]. Comments. Leaves of Piper nokaidoyitau are pinnately nerved throughout with 4–5 ascending secondary veins on each side. This characteristic is shared by other species belonging to the Radula clade, specifically subclade Isophyllon (Jaramillo et al. 2008). We compared P. nokaidoyitau with similar species that occur on the eastern slope of the northern Andes (Table 4).