PolylepisracemosaRuiz & Pav.var.lanata Kuntze, Revis. Gen. Pl. 3(3): 77. 1898.

Bolivia. Cochabamba: Tunari, 3000–4000 m, Kuntze s.n (holotype: B destroyed; isotype: NY).

Trees 2–20(-32) m tall. Leaves slightly congested at the branch tips, imparipinnate with 2–3 pairs of leaflets, obtrullate in outline, (4.2–)6.6–8.1 × 2.9–5.1 cm; rachises densely lanate, points of leaflet attachment with a tuft of long hairs; stipular sheaths apically acute with spurs, densely lanate on the outer surfaces; leaflets obovate to broadly obovate in outline, second pair from the terminal leaflet the largest, one of this pair (1.8–)2.2–2.7 × 0.9–1.4 cm; margin crenate with 5–9 teeth, apically emarginate, basally unequally cordate; upper leaflet surfaces sparsely lanate; lower leaflet surfaces densely lanate with whitish hairs 1.4–1.5 mm long. Inflorescences pendant, (5.0–)6.1–12.3 cm long, bearing 5–7(–11) flowers; floral bracts 4.7–7.5 mm long, narrowly triangular, densely lanate on the outer surface; rachises lanate. Flowers 8.4–9.4 mm diam.; sepals 4, ovate, green, densely lanate outside; stamens 15–19, anthers orbicular, with a dense tuft of straight white hairs on the upper half; styles fimbriate, 2.5–3.2 mm long. Fruits turbinate, with 2–4 irregular flattened ridges with a series of spines, densely pilose; 5.5–10.0 × 4.9–7.7 mm including spines. Tetraploid.

Polylepislanata is restricted to the Cordillera Tunari and the adjacent Cotacajes Valley in Cochabamba (Bolivia) (Fig. 92). It occurs at 2800–3970 m elevation in humid Yungas forest where it co-occurs with P.canoi in mixed forest with Alnusacuminata, Valleastipularis, Prumnopithysexigua, Podocarpusglomerata, Weinmanniafagaroides and Oreopanax spp. (Kessler 1995b). In the Tunari mountains at 3220–3420 m elevation, P.lanata grows in mixed forest dominated by typical Yungas species, such as Hesperomeleslanuginosa and Escalloniamyrtilloides (Navarro et al. 2005). In general, the Cochabamba region is considered as an important area for Neotropical bird conservation (Wege and Long 1995; Fjeldså and Kessler 1996). This region is one of the areas with the greatest diversity of birds of Polylepis forests in Bolivia, including species, such as Pseudosaltator (= Saltator) rufiventris and Cranioleucapyrrhophia which occur in drier areas and typical humid Yungas species, such as Conirostrumferrugineiventre and Thlypopsisruficeps, as well as specialists like Conirostrumbinghami (= Oreomanesfraseri) (Navarro et al. 2010). Forests of P.lanata are often isolated from the closed treeline because ground fires can spread through open Polylepis forest, but not through the humid cloud forest (Kessler 2000). An isolated forest patch at 3650 m elevation had a mean tree height of about 20 m, with individual trees reaching 32 m, making this one of the tallest species of Polylepis (Hertel and Wesche 2008).

The EOO for Polylepislanata is estimated as 5,683 km², the AOO is assessed at 60 km² and it is known from 13 locations. It is protected within Carrasco National Park. The species was categorized as VU (B1+2c, D2) in the World List of Threatened Trees (Oldfield et al. 1998). However, later it was categorized as EN (B1+2ab(ii,iii,iv)) in the Red List of Threatened Flora of Bolivia (Arrázola and Coronado 2012). Logging, firewood, livestock and fire are threats for its ecosystem (Navarro et al. 2010; Arrázola and Coronado 2012). We assess the species as Endangered (B1a+B2a, D2a).

Polylepislanata can be distinguished from the most similar species P.triacontandra by having 2–3 versus 1(–2) lateral leaflet pairs, emarginate versus acute to revolute leaflet apices and lanate, 1.4–1.5 mm long versus tomentose, 0.4–0.8 mm long hairs on the lower leaflet surfaces. Polylepislanata further has fewer flowers per inflorescence (15–19 versus 21–23) and shorter styles (2.5–3.2 mm versus 3.3–3.8 mm). Occasionally, specimens of P.lanata resemble those of P.pacensis in having the same number of lateral leaflet pairs, leaflet shape, apex and margins, but it differs in hair length and type (lanate, 1.4–1.5 mm versus villous, 0.4–0.9 mm). Polylepislanata has also been confused with P.sacra (see P.sacra). Hybrids of P.lanata with both P.besseri and P.subtusalbida have been reported by Kessler (1995b).

Bolivia. Cochabamba: Ayopaya, 3 km al N de Saila Pata, 16°54'S, 066°56'W, 3150 m, 14 November 1997, Kessler 12440 (GOET!); Bosque situado a 5 km, subiendo en dirección Oeste de Independencia, cerca de la comunidad de Kuri Barranca, parte alta, 3500 m, 05 November 1987, Mérida 4 (GOET!, MO!). Carrasco, Com. Lachujmayu, 3200 m, 22 November 1991, Hensen 934 (GOET!); Surroundings of Monte Punco, 17°36'S, 065°17'W, 2800 m, 15 August 1991, Kessler 2956 (GOET!); 3 Km N Cocapata off Cochabamba-Santa Cruz road, 17°34'S, 065°19'W, 3000 m, 15 August 1991, Kessler 2961 (AAU!, GOET!, MO!); 2962 (GOET!); 2963 (AAU!, GOET!); 2964; 2965 (GOET!, MO!); 3493 (GOET!); Lope Mendoza, 17°32'58"S, 065°21'58"W, 3453 m, 27 December 1998, Mercado 1959 (MO!). Cercado, Ladera Sur del Parque Nacional Tunari, 17°05'42"S, 066°19'52"W, 3800 m, Terán 4421 (BOLV). Chapare, Cantón Colomi 8 km al NW de Colomi, Candelaria Pie de gallo, zona Chimparancho, 17°10'00"S, 065°58'00"W, 3200 m, 23 April 1989, Beck 18100 (GOET!, MO!); Mayka Mayu, 3300 m, 02 April 1991, Hensen 2249 (MO!); Candelaria, 3300 m, 04 April 1991, Hensen 2280 (GOET!); Mayka Mayu, 3300 m, 28 July 1990, Hensen 850 (GOET!); Mayka Mayu, ca. 60 km N Sacaba, 17°12'S, 065°58'W, 3300 m, 11 August 1991, Kessler 2850 (AAU!, GOET!); 2851 (AAU!); 2870; 2871; 2873; 2876 (GOET!); 3402 (AAU!, GOET!, LPB, MO!); 3483; 3484; 3485; 3486; 3487; 3488 (GOET!); ca. 4 km N Mayka Mayu, ca. 65 km from Sacaba, 17°12'S, 065°58'W, 3350 m, 13 August 1991, Kessler 2933 (AAU!, GOET!); 3490; 3491; 3492 (GOET!); Km 76 camino antiguo a los yungas del Chapare entrando por Aguirre, 24 April 1999, Mercado 2213 (MO!); 14.7 km N of Colomi (junction of the road to Candelaria) on road to the Chapare, 17°15'S, 065°53'W, 3300 m, 19 October 1985, Solomon 14421 (LPB, MO!). Vinto, Tunari, 17°19'00"S, 066°21'00"W, 3000–4000 m, Kuntze s.n (B, NY). La Paz: Inquisivi, Unos 8 km. de Quime hacia Inquisivi, Camillaya arriba del pueblo, 16°58'S, 067°12'W, 3000 m, 29 September 1997, Beck 24367 (MO!); along the trail and on slopes W of trail, between Pongo Chico and Laguna Naranjani, 16°59'S, 067°15'W, 08 July 1988, Lewis 881028 (MO!). Irupana, Kakhani, 16°41'00"S, 067°36'00"W, 3322 m, 27 June 2004, Chumacero 483 (LPB); 484 (LPB); 485 (LPB). Sud Yungas, camino a Lambate, 16°36'10"S, 067°42'25"W, 3386 m, 26 July 2009, Palabral 670A (LPB). Cult. at Jardín Botánico La Paz 2000, from seeds collected at Cochabamba: Mayka Mayu 1991, Kessler 12629 (GOET!).