Xenophyllum esquilachense (Cuatrec.) V.A.Funk, Novon 7(3): 239. 1997.

Calvo, Joel & Moreira-Munoz, Andres, 2020, Taxonomic revision of the Andean genus Xenophyllum (Compositae, Senecioneae), PhytoKeys 158, pp. 1-106 : 1

22. Xenophyllum esquilachense (Cuatrec.) V.A.Funk, Novon 7(3): 239. 1997.

Werneria esquilachensis Cuatrec., Brittonia 8: 192. 1956. Type. Peru. Puno: San Antonio de Esquilache, 4725 m, 12 May 1937, D. Stafford 716 (holotype: K s.n.!).

Senecio pfisteri Ricardi & Martic., Gayana, Bot. 11: 25. 1964. Type. Chile. Arica-Parinacota: Arica, Portezuelo de Chapiquiña, faldeos al lado norte del campamento, 4400 m, 10 Feb 1964, C. Marticorena, O. Matthei & M. Quezada 116 (holotype: CONC-29863!; isotype: CONC s.n.!).

Description.

Suffruticose plant, forming clumps of erect or decumbent stems. Rhizomes 4-8 × 0.1-0.2 cm, horizontal to oblique, glabrous. Stems 5-10 cm tall, branched, glabrescent, usually with leaves restricted to the upper part. Leaves somewhat distantly arranged, abruptly narrowed at the base; leaf laminas 11.2-15.5 × 3.3-4.6 mm, broadly spatulate, 3-forked at the apex, entire and scabrous-ciliate (cilia ca. 0.17 mm long), flat in cross section, glabrous, 1-nerved above (barely visible), 1-nerved beneath, somewhat fleshy, matte, papillose; leaf lobes 2.4-3.9 × 0.7-1 mm, with 2 to 3 rough mucronate teeth up to 1.4 mm long. Capitula disciform, erect, sessile to subsessile. Involucres 10.4-15.1 × 6.5-7.4 mm, cupuliform; involucral bracts 8 to 12, 5.4-7.2 × 1.3-2.5 mm, acute to obtuse at the apex, greenish, sometimes purple-edged. Peripheral florets ca. 10, pistillate; corollas reduced to a vestigial tube ca. 2.1 mm long or without corolla. Disc florets ca. 15; corollas 6-10.6 mm long, purplish; style branches truncate with a crown of sweeping trichomes, purplish. Achenes cylindrical, glabrous (immature); pappus ca. 11.3 mm long, barbellate, whitish. Chromosome number unknown.

Iconography.

Calvo et al. (2018: 289, fig. 1, as photo).

Distribution and habitat.

Southern Peru to central-western Bolivia. Bolivia (Oruro), Chile (Arica-Parinacota), Peru (Arequipa, Moquegua, Puno, Tacna). It grows in rocky outcrops, steep volcanic slopes, and open shrublands of the subhumid and dry puna ecoregions, between elevations of 3700-4950 m (Fig. 27 ).

Phenology.

Flowering from February to June.

Etymology.

It is named after the Peruvian village of San Antonio de Esquilache (western Puno), where the type material was collected in 1937 by Dora Stafford.

Notes.

This is the unique species within the genus displaying disciform capitula. They have ca. 10, peripheral, pistillate florets with a corolla reduced to a vestigial tube ca. 2.1 mm long or without corolla, and therefore, the style is exsert in its whole length or almost so. Another distinctive feature is the morphology of the leaves; they are 3-forked, abruptly narrowed at the base, and marginally scabrous-ciliate. Each lobe usually has 2 to 3 rough mucronate teeth. Any confusion with the other members of the genus is unlikely.

See Calvo et al. (2018) for further details on the type material of the name Senecio pfisteri Ricardi & Martic.

Additional specimens examined.

Bolivia. Oruro: Challapata, Livichuco, Tarpata, estribaciones del cerro Toro en el collado antes de las lagunas, 18°57'S, 66°24'W, 15 Feb 2019, J. Calvo & M. Zárate 7877 (BOLV); prov. Eduardo Abaroa, Challapata, comunidad Churacani, 18°55'S, 66°40'W, 1 Apr 2018, M. Guzmán 124 (LPB); Abaroa, Challapata, cerro Toro Ichurata, en línea recta a 34.38 km al E, 18°57'S, 66°27'W, 27 Feb 2016, F. Zenteno, L. Moya & D. Villalba 16745 (LPB). Chile. Arica-Parinacota: quebrada Cataguanchuta, 18°14'S, 69°31'W, 17 Dec 1988, E. Belmonte 88644 (CONC); pasado azufrera Tacora, 17°42'S, 69°49'W, 17 Mar 2015, A. Moreira-Muñoz & F. Luebert 2407 (SGO); Portezuelo de Chapiquiña, 18°19'S, 69°30'W, 26 Mar 1961, M. Ricardi, C. Marticorena & O. Matthei 207 (CONC). Peru. Arequipa: Chiguata, faldas del nevado Pichu Pichu, 16°27'S, 71°27'W, 20 Jun 2004, V. Quipuscoa et al. 2949 (HSP); Chiguata, ca. 2 km arriba del túnel del Simbral, carretera a Salinas, 16°22'S, 71°17'W, 15 Apr 2018, V. Quipuscoa & M. Balvin 7541 (HSP); Moquegua: Mariscal Nieto, Carumas, cerca a un acueducto, 16°50'S, 70°34'W, 15 Jun 2013, H. Beltrán 7734 (USM); General Sánchez Cerro, Yunga, Sura-Perusa, 16°11'S, 70°38'W, 13 Apr 2012, D. Montesinos 3804 (HSP); General Sánchez Cerro, Yunga, Perusa, 16°11'S, 70°37'W, 3 Mar 2018, D. Montesinos & J. Calvo 5958 (HSP); Tacna: Tarata, Poma, carretera Tarata-Puno, 17°25'S, 69°56'W, 25 Mar 1998, A. Cano 8139 (USM).

Figures

Figure 27. Distribution map of Xenophyllum staffordiae (left hand) and X. esquilachense (right hand).