Polylepis hieronymi Pilger, Bot. Jahrb. Syst. 37: 534. 1906.

Boza Espinoza, Tatiana Erika & Kessler, Michael, 2022, A monograph of the genus Polylepis (Rosaceae), PhytoKeys 203, pp. 1-274 : 1

16. Polylepis hieronymi Pilger, Bot. Jahrb. Syst. 37: 534. 1906.

Figs 47 , 48

Polylepis hypoleuca (Weddell) Bitter, Bot. Jahrb. Syst. 45: 607. 1911.

Polylepis racemosa β Polylepis hypoleuca Weddell, Chlor. Andina 2:238. 1857 [1861]. Basionym. Type. Bolivia. Tarija: between Tarija and San Luis, July-August 1846, Weddell 4607 (lectotype, designated by Simpson 1979, pg. 23: P).

Polylepis racemosa var. albotomentella Kuntze, Revis. Gen. Pl. 3: 77. 1898. Type. Argentina. Córdoba: Sierra de Córdoba, Los Gigantes, Kurtz 6926 (holotype: NY!).

Polylepis australis var. bijuga Bitter (1911: 624) Nom. illeg.

Polylepis hieronymi var. d olicholopha Bitter (1911:609). Nom. illeg.

Polylepis hieronymi var. saltensis Bitter, Bot. Jahrb. Syst. 45: 609. 1911. Type. Argentina. Salta: near Pampa Granda, pass "El Alizar", 2400-2600 m, 1900, Nelson 12584 (holotype: S).

Type.

Bolivia. Tarija: Salinas, Cuesta de Polla, Valle del Tambo , June 1873, Lorentz & Hieronymus 938a (holotype: B destroyed; isotypes: G!, GOET!, NY!) .

Description.

Trees 3-8(-25) m tall. Leaves slightly congested at the branch tips, imparipinnate with 3-4 pairs of lateral leaflets, obtrullate in outline, (3.3-)3.6-5.2 × 2.1-3.1 cm; rachises densely tomentose, points of leaflet attachment with a tuft of long, lanate hairs; stipular sheaths apically truncate with spurs, densely sericeous on the outer surfaces; leaflets narrowly obovate in outline, second pair from the terminal leaflet the largest, one of this pair (1.2-)1.5-2.1 × 0.6-1.0 cm; margin crenate with 5-7 teeth, apically emarginate, basally unequally cordate; upper leaflet surfaces sparsely tomentose; lower leaflet surfaces densely tomentose with whitish hairs 0.8-1.1 mm long. Inflorescences pendant, (4.5-)5.6-7.5(-8.1) cm long, bearing 13-25 flowers; floral bracts 3.2-6.3 mm long, narrowly triangular, densely lanate on the outer surface; rachises villous. Flowers 5.4-6.5 mm diam.; sepals 4, ovate, green, densely sericeous outside; stamens 9-19, anthers orbicular, with a dense tuft of straight white hairs on the upper half; styles fimbriate, 2.3-3.9 mm long. Fruits almost cylindrical, with variable numbers and placement of long spines, densely lanose; (4.1-)6.0-6.4(-8.3) × 3.5-7.0 mm including spines. Diploid.

Distribution, habitat and ecology.

Polylepis hieronymi occurs in Boliviano-Tucumanic forests at 1500-3450 m elevation (Fig. 61 ). It grows in relatively dry areas as a pioneer species that often colonizes landslides and roadsides in mixed forests with Podocarpus parlatorei and Alnus acuminata ( Kessler 1995b; Gareca et al. 2010). Trees of P. hieronymi often grow as isolated individuals or small stands mixed in forest dominated by typical high Yungas species. It also occurs on very steep slopes with shallow soils that do not permit persistence of taller trees ( Bellis et al. 2014). Thus, the ecology of P. hieronymi is different from that of almost all other Polylepis species, which usually dominate the canopy of the forest they belong to ( Renison et al. 2013). Polylepis specialist birds are absent in forests of P. hieronymi , possibly because they do not form large, mature forests ( Bellis et al. 2014). Polylepis hieronymi occasionally co-occurs with P. australis in Salta and Jujuy (Argentina) and with P. crista-galli in Chuquisaca (Bolivia), but hybrids have not been found to date.

Conservation status.

Based on 28 collecting localities, the estimated EOO is 150,691 km2 and the AOO is 148 km2. It was categorized as VU (B1+2c) in the World List of Threatened Trees ( Oldfield et al. 1998). In Bolivia, it occurs in Cordillera de Sama Biological Reserve in Tarija. We assess P. hieronymi as Vulnerable (B1a+B2ac).

Notes.

Sterile individuals of P. hieronymi can be confused with sterile plants of P. besseri , also because both species broadly overlap in distribution. Both species have quite similar leaflet shapes and texture, numbers of lateral leaflet pairs and densely tomentose lower leaflet surfaces. If no fruits are available (spiny in P. hieronymi , with broad ridges in P. besseri ), they are best distinguished by the sericeous hairs on the stipular sheaths in P. hieronymi and tomentose hairs in P. besseri . Polylepis hieronymi also somewhat resembles P. neglecta in having 3-4 lateral leaflet pairs and relatively long inflorescences with many flowers. However, it has narrowly obovate leaflets with crenate margin and tomentose hairs 0.8-1.1 mm long, styles 2.3-3.9 mm long and spiny fruits, whereas P. neglecta has elliptic leaflets with serrate margins and glabrous to puberulous lower surfaces, shorter styles 1.5-2.2 mm long and winged fruits.

Specimens examined.

Argentina. Jujuy: Capital, Tiraxi, Alto Salviar , ladera E, 08 November 1989, Tupayachi s.n (MO!) . Salta: Guachipas, Cuesta del La jar, 1600-1700 m, 07 February 1983, Novara 3142 (MO!) .

Bolivia. Chuquisaca: Azurduy, Saliendo de Azurduy hacia el rio Pilcomayo , 20°12'52"S, 064°26'37"W, 3114 m, 15 October 2007, Cervantes 187 (HSB, MO!); Belisario Boeto, Trayecto Villa Serrano hacia la comunidad de Tampa Mayu y Nuevo Mundo , 19°00'04"S, 064°18'55"W, 2297 m, 12 December 2007, Cervantes 157 B (HSB, MO!); 1 km S Nuevo Mundo on road to Padilla , 19°28'S, 064°10'W, 2200 m, 07 October 1991, Kessler 3306 (GOET!, LPB); 3307 (AAU!, GOET!, MO!); 3308 (AAU!, GOET!, MO!); 3309 (GOET!); 8 km SW Nuevo Mundo on road to Padilla , 19°25'S, 064°11'W, 2500 m, 07 October 1991, Kessler 3317 (GOET!); 3318 (GOET!); 3321 (GOET!); próximo a Lagunillas, 2240 m, 24 January 1988, Murguía 128 (LPB); Hernando Siles, subiendo de la Hacienda Guzman para el Abra, 20°17'16"S, 064°02'56"W, 1993 m, 24 December 2005, Peñaranda 22 (HSB, MO!, QCA!); Oropeza, Municipio de Yotala , Canton Huayllas. Comunidad Pitatorillas, 19°09'06"S, 065°20'48"W, 3374 m, 23 September 2007, Jiménez 376 (HSB, MO!, QCA!). Sud Cinti, Cerro Cobre Khasa, between Culpina and El Palmar, 20°48'S, 064°34'W, 3100 m, 21 September 1991, Fjeldså s.n (GOET!). Tomina, 25 km hacia Montegudo, 19°03'S, 064°16'W, 2400 m, 01 October 1983, Beck 9345 (BOLV, GOET!, LPB, MO!, NY); ca. 20 km SE Padilla on road to Monteagudo, 19°03'S, 064°16'W, 2450 m, 07 October 1991, Kessler 3319 (AAU!, GOET!); Trayecto Lima Bamba - EL Villar, 19°33'01"S, 064°19'55"W, 2553 m, 13 October 2007, Portal 138 (HSB, MO!) . Santa Cruz: Mairana, within the Flora de la Region del Parque Nacional Amboro, but above the 700 m contour, 18°06'30"S, 063°57'00"W, 2000-2100 m, Nee 43429 (MO!, NY). Manuel Maria Caballero , Parque Nacional Amboro . San Juan del Potrero ; entre Yunguillas y cabeceras del rio Zapallar , 17°53'S, 064°25'W, 2300-2400 m, 12-13 May 1992, Vargas 1350 (MO!, NY, USZ). Vallegrande, between “Mataralcito” and "El Palmar" on road from Valle Grande to Tierras Nuevas, 17 km by air ESE of Valle Grande, 18°32'00"S, 065°57'00"W, 2150 m, 29 December 1988, Nee 37403 (NY); camino de Tierras Nuevas a Vallegrande, 18°30'27"S, 063°55'04"W, 2249 m, 31 July 2011, Parada-Gutierrez 3580 (MO!, USZ); camino hacia Khasa Monte, sobre la cima de la serrania, 18°38'09"S, 064°02'01"W, 2550 m, 04 August 2011, Parada-Gutierrez 3671 (MO!, USZ); camino del Cruce hacia Alto Seco, 18°44'45"S, 064°06'53"W, 2717 m, 08 July 2011, Parada-Gutierrez 3746 (MO!, USZ); Senegilla a 17 km de Vallegrande, 18°40'03"S, 064°01'55"W, 2400 m, 20 August 2012, Parada-Gutierrez 4828 (MO!, USZ); a 4 km al norte de Postrervalle sobre el camino a Mairana, 2000 m, 13 November 1999, Saldias 6192 (USZ). Vallegrande, 2363 m, 24 August 2008, Arroyo 4007 (QCA!); Meson at Samaipata, 2200 m, 01 March 1911, Herzog 1786a (GOET!) . Tarija: Arce, 43 km hacia Padcaya, Huancanqui , 2500-2600 m, 20 November 1986, Beck 14080 (GOET!); cerca de Camacho, 2600 m, 17 December 1987, Beck 16067 (GOET!); bajando del Abra del Cerro Cabildo hacia el S via estancia Cabildo , 2350 m, 29 January 1988, Beck 16240 (GOET!); ca. 5 km W Padcaya, 21°54'S, 064°46'W, 2200 m, 18 September 1991, Kessler 3114 (AAU!, GOET!); 3646 (GOET!); detras de Padcaya , 2450 m, 23 January 1988, Liberman 1637 (GOET!); Municipio Padcaya , Cantón Emborozú, Reserva Natural Alarachi, recorrido a cima más alta de la Zona Alarachi, próximo al Cerro Yauparuna, 22°10'44"S, 064°36'33"W, 2260-2380 m, 16 September 2004, Serrano 4828 (MO!); 39.9 km S of jct. of road to Entre Rios, on road to Padcaya , 21°54'S, 064°41'W, 2100-2200 m, 29 April 1983, Solomon 10218 (LPB, MO!, NY). O’Connor, ca. 5 Km W Padcaya , 21°54'S, 064°46'W, 2200 m, 18 September 1991, Kessler 3113 (AAU!, GOET!, MO!); 3115 (GOET!, MO!); ca. 70 km on road from Tarija to Entre Rios, 21°26'S, 064°19'W, 2200 m, 20 September 1991, Kessler 3123; 3124 (AAU!, GOET!); 3125 (GOET!, MO!); 3660 (AAU!, GOET!, MO!); 21.1 km on road to entre Rios, 21°27'S, 064°20'W, 1900 m, 01 October 1983, Solomon 10918 (LPB, MO!). Valle del Tambo bei Tarija, 10 June 1973, Hieronymus 938 (GOET!); Cult. at Jardin Botanico La Paz 2000 from seeds, s.d., Kessler 12625 (GOET!). s.d., Cárdenas 3906 (US!); 3907 (US!); Salinas, Cuestas de Polla , in valle Tambo, June 1873, Hieronymus 938a (B, F!); s.d., Hieronymus 938a (B, MO!) .

Figures

Figure 47. Polylepis hieronymi Pilger A flowering branch B upper leaf surface C lower leaf surface D flower and young fruit E stipule sheaths F leaves G flowering branch H bark I flowering branch. Scale bars: 3 cm (A); 1 cm (B, C, F); 5 mm (D, E, G). Photographs by M. Kessler.

Figure 48. Polylepis hieronymi Pilger A flowering branch B lower leaf surface C upper leaf surface D fruit E stipular sheaths (A Kessler 3114 B Kessler 3306 C Kessler 3308 D Kessler 3319 E Kessler 3318). Scale bars: 2 cm (A-C); 5 mm (D). Photographs by T. E. Boza E.

Figure 61. Geographical distribution of the species of section Polylepis Reticulatae.