Peru. Cajamarca: at Chugur near Hualgayoc, 2700–3000 m, May 1904, Weberbauer 4098 (holotype: G!; isotypes: MOL!; photos at F!, MO!).

Trees 5–15 m tall. Leaves slightly congested at the branch tips, imparipinnate with 5–7 pairs of lateral leaflets, obtrullate in outline, (11.0–)14.6–19.5 × 6.2–9.1(–10.7) cm; rachises densely lanate, points of leaflet attachment with a tuft of long, lanate hairs; stipular sheaths apically acute with spurs, densely lanate on the outer surfaces; leaflets elliptic in outline, second pair from the terminal leaflet the largest, one of this pair 2.9–3.6(–5.4) × 1.1–2.0 cm; margin serrate with 6–10 teeth, apically obtuse, basally unequally cordate; upper leaflet surfaces glabrous or sparsely villous; lower leaflet surfaces densely villous with whitish hairs 0.9–2.3 mm long. Inflorescences pendant, (15.4–)21.7–28.2(–36.0) cm long, bearing 47–83 flowers; floral bracts 7.6–9.7 mm long, narrowly triangular, densely villous on the outer surface; rachises villous. Flowers 6.4–7.5 mm diam.; sepals 4, ovate, green, densely lanate outside; stamens 7–13, anthers orbicular, with a dense tuft of straight white hairs on the upper half; styles fimbriate, 1.9–3.8 mm long. Fruits turbinate, with variable numbers and placement of irregular spines, densely villous; 4.5–9.6 × 6.0–10.1 mm including spines. Diploid.

Polylepismultijuga is restricted to northern Peru (Fig. 24). It grows mainly in the upper montane forest at 2700–3750 m elevation, usually in mixed forest with species of Cyathea, Escallonia, Gynoxys and Weinmannia (Weberbauer 1911). Its branches are often covered with epiphytes (Simpson 1979).

Based on 22 localities, the EOO for Polylepismultijuga is estimated at 17,200 km² and the AOO at 116 km². The species was categorized as VU (B1+2c, D2) in the World List of Threatened Trees (Oldfield et al. 1998). Later, based on its fragmented habitat affected by human disturbance, it was listed as EN (B1ab(iii)) in the Red List of Peru (SERFOR 2006; León-Yánez et al. 2011). It does not occur in any protected area and mining and forestry activities have led to its disappearance at several former locations (Guerrero 2009). Deforestation of remnant P.multijuga patches and extended reforestation with Pinus, which dries and acidifies the soils, are further reducing populations. The small, fragmented, and declining populations of this species are characterized by low genetic diversity (Quinteros-Casaverde et al. 2012). Based on its fragmented and degraded distribution, continuing habitat loss, and lack of habitat protection, we assess P.multijuga as Critically Endangered (A1, B1a+B2a, C1).

Polylepismultijuga is similar to P.canoi but has 5–7 pairs of elliptic leaflets, whereas the latter has 2–4 pairs of obovate leaflets. Polylepismultijuga also has longer inflorescences (15.4–36.0 cm) with 47–83 flowers (P.canoi 8.2–14.5 cm, 12–26 flowers). Polylepismultijuga is also similar to P.ochreata, but differs by having larger and broader leaflets (2.9–5.4 × 1.1–2.0 cm versus 1.6–3.0 × 0.5–0.7 cm) and densely villous lower leaflet surfaces (densely sericeous in P.ochreata). Polylepisochreata also has shorter inflorescenses (8.1–17.4 cm) with fewer flowers (21–49).

Peru. Amazonas: Chachapoyas, Dist. Leymebamba, surroundings of La Esperanza, 06°49'04"S, 077°43'01"W, 3200–3300 m, 27 June 2010, Glenn 411 (CAS, COL!, F!, K, MO!, P!); Dist. Leymebamba. Río El Jardín, 06°55'52"S, 077°43'09"W, 3370 m, 30 June 2009, Gruhn 173 (MO!); Dist. Leymebamba, a 2 Km de la Laguna de Los Cóndores, ruta hacia Leymebamba, 2700–2950 m, 18 August 1998, Quipuscoa 1329 (MO!); Quintecocha. Dist. Leymebamba, vicinity of guard cabin at Quintecocha, 06°51'33"S, 077°42'15"W, 3134 m, 12 July 2008, Rothrock 239 (BRIT, MO!); Balsas, Chuquillurco, ruta a Calla Calla, 3400 m, 06 October 2001, Sánchez 11018 (MO!); Chachapoyas-Cajamarca road, jalca de Calla-Calla, 30–37 km from Leimebamba Natural grassland, ‘Jalca’, and ‘ceja de selva’ just leaving the pass entering the Marañon valley, 06°50'S, 077°50'W, 3500–3600 m, 04 September 1983, Smith 5037 (MO!, USM!); Leimebamba, Oseres, 06°58'05"S, 077°39'57"W, 2542 m, 22 May 2015, Vega 257 (HAO, MO!); road Balsas to Chachapoyas, upper eastern Calla-calla slopes descending from pass, 3000–3300 m, 02 June 1998, Weigend 98/330 (USM!). Luya, Distr. Conila-Cohechan, 06°16'25"S, 078°00'10"W, 3050 m, 23 August 2012, Bussmann 17289 (MO!); Colcamar, 3200–3300 m, 24–26 June 1948, Pennell 15632 (USM!). Cajamarca: Chota, Bosque de Pagaibamba (Ocshawilca), al oeste del Chorroblanco, entre Huambos y Querocoto, 2500 m, 18 October 1987, Sánchez 4588 (F!); Paccha, al O de Chadin, 3650 m, 22 July 1993, Sánchez 6586 (F!). Cutervo, Gruta de San Andres, 2200 m, 15 July 1990, Llatas 2749 (F!, MO!). Hualgayoc, Dist. de Chugur, 06°43'08"S, 078°42'58"W, 3222–3568 m, 12 August 2009, Castillo 786 (USM!); Hacienda Taulis, 13 km beyond Palmito junction towards La Playa, 2900 m, 02 September 1964, Hutchison 6463 (MO!, USM!); Chugur, sobre la ruta de Perlamayo, 2950–3000 m, 20 March 1988, Sánchez 4681 (AAU!, F!). San Miguel, El Prado, Hacienda Taulis, 06°59'02"S, 078°58'21"W, 3398 m, 01 June 2015, Boza 3029; 3070; 3071; 3072; 3073; 3074; 3075; 3076; 3077; 3078; 3079; 3080 (USM!, Z!); Quishuarpampa (Agua Blanca), 2900 m, 04 July 1986, Mostacero 1201 (F!, MO!); Quishuarpampa (El Tingo–Jalca de las Estacas), 07°21'00"S, 077°50'00"W, 2950 m, 12 May 1977, Sagástegui 8833 (MO!); Millán (El Tingo–Taulis), 3000 m, 20 June 1980, Sagástegui 9536 (F!, MO!, USM!); Sobre el desvio a Tongot, entre Quilcate bajo y Catilluc, 3050 m, 13 September 1991, Sánchez 5762 (MO!). Santa Cruz, Distr. Pulán, parte baja de la Quebrada Cocan, ladera Oeste, 3280 m, 02 November 2001, Sánchez 11112 (MO!); Dist. Pulan, La Palma, 2800 m, 12 February 2007, Santa 927 (USM!); ad Chugur versus Hualgayoc, 2700–2900 m, 1901–1929, Weberbauer 4098 (G, MO!). La Libertad: Bolivar, District Uchumarca, Páramo in surroundings of Vira Vira/Lagunas La Quinua, 07°00'12"S, 077°45'07"W, 3670 m, 17 May 2011, Bussmann 16931 (MO!). Huicungo, Dist. Uchumarca, 06°59'30"S, 077°43'07"W, 3140 m, 02 November 2012, Paniagua 8642 (MO!). Lambayeque: Ferrenafe, Dos Puentes, arriba de Incahuasi, 2900–3000 m, 09 July 1987, Ferreyra 20908 (USM!); road Incahuasi to Sinchihual and Tungula, 06°12'07"S, 079°17'57"W, 2897 m, 24 November 2014, Weigend 9660 (USM!).