Xenophyllum crassum subsp. orientale (Cuatrec.) J.Calvo, 2020

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

7b. Xenophyllum crassum subsp. orientale (Cuatrec.) J.Calvo comb. nov.

Werneria crassa subsp. orientalis Cuatrec., Phytologia 45: 29. 1980. Type. Colombia. Santander: páramo del Almorzadero, vertiente norte, 3600-3800 m, 28 Nov 1941, J. Cuatrecasas 13511 (holotype: US-00037302!; isotypes: BC-634974 (digital image!), F-1233032!).

Werneria crassa f. minor Cuatrec., nom. nud. in sched. ( Turland et al. 2018, ICN Art. 38.1).

Description.

Stems 1.5-2.5 cm tall (aerial part), lanate. Leaves stellate-imbricate, extending into a sheath-like base that bears long silky trichomes, usually with the leaf lamina spreading at nearly 90° from the sheath-like base; leaf laminas 6.5-12.7 × 1.2-2 mm, linear, obtuse, usually callous-like tipped at the apex, entire, flat to elliptical in cross section, glabrous, 1-nerved above, 1-nerved beneath, fleshy, rather shiny (in dried specimens). Capitula radiate, erect, sessile to subsessile (rarely with a short peduncle up to 8 mm long). Involucres 10.2-12.2 × 7.8-10.6 mm, cupuliform; involucral bracts 11 to 13, 6-8.2 × 1.6-2.1 mm, acute to obtuse at the apex, greenish to dark-purplish. Ray florets 13 to 15; corollas 13-13.2 × 1.7-2.6 mm, 4 to 5-veined, subentire to 3-toothed at the apex, conspicuously surpassing the involucre, white. Disc florets ca. 50; corollas 6.6-6.9 mm long, yellow. Achenes cylindrical, glabrous (immature); pappus 7.8-8 mm long, barbellate, whitish. Chromosome number unknown.

Distribution and habitat.

Endemic to Colombia (Arauca [expected], Boyacá, Norte de Santander, Santander). It grows in marshes and wet exposed areas of the paramo ecoregion, between elevations of 3200-4600 m (Fig. 12 ).

Phenology.

Flowering nearly all year round.

Etymology.

The adjective orientalis -is -e means eastern, which refers to the further eastern distribution of this taxon in relation to the typical subspecies. It occurs in the northern part of the Cordillera Oriental of Colombia (Eastern Ranges).

Notes.

Xenophyllum crassum subsp. orientale is characterized by the leaf length (6.5-12.7 mm), the number of involucral bracts (11 to 13), and the number of ray florets (13 to 15). In dried specimens, the leaves are rather shiny. This taxon was synonymized with X. crassum subsp. crassum by Ávila et al. (2016) but no discussion supporting such taxonomic decision was provided. The aforementioned morphological differences against the typical subspecies, in addition to the fact that their distribution areas are well defined and do not overlap, lead us to maintain the treatment by Cuatrecasas (1980).

It should be noted that X. crassum subsp. orientale has been confused with Werneria pygmaea , a species that grows in the same habitat. Indeed, we detected several specimens that contain mixed material, including an isotype (see comments below). Xenophyllum crassum subsp. orientale has erect, robust rhizome-like stems whereas W. pygmaea is a strictly rosettiform species not forming hummocks. Further differences are detailed in Calvo et al. (in press). Some confusion with X. humile is also likely (see comments under it).

The presumed isotype of W. crassa subsp. orientalis Cuatrec. kept at COL (COL-000005514) comes from "extremo S en Peralonso, 3100 m", a locality slightly different from that indicated in the protologue, i.e., "vertiente norte, 3700-3800 m" [as "3600-3800 m" on the labels]. It is excluded from the type material as it does not belong to the same gathering. On the other hand, it has to be noted that the isotype at BC contains an individual corresponding to W. pygmaea (above on the right hand, with fragments of Disterigma sp. ( Ericaceae ) at the base).

Additional specimens examined.

Colombia. Boyacá: Cordillera Oriental, Sierra Nevada del Cocuy, Alto Ritacuva, 6°30'N, 72°19'W, 11 Apr 1959, H.G. Barclay & P. Juajibioy 7352 (COL, US); páramo de Monguí, laguna Colorada, 5°38'N, 72°50'W, 1 Sep 1998, J.A. Calleja & J.C. Jaramillo 204 (COL); Sierra Nevada del Cocuy, alto valle Lagunillas, 500 m al NNE de la laguna Pintada, 6°22'N, 72°19'W, 3 Oct 1972, A.M. Cleef & P.A. Florschütz 5784 (COL, US); Sierra Nevada del Cocuy, quebrada Bocatoma, morrena al W de la lagunita glaciar occidental, 6°23'N, 72°16'W, 5 Nov 1972, A.M. Cleef & P.A. Florschütz 5870 (COL); Sierra Nevada del Cocuy, quebrada Bocatoma, laguna rellena, 6°23'N, 72°16'W, 3 Mar 1973, A.M. Cleef 8736 (COL, US); Sierra Nevada del Cocuy, quebrada Bocatoma, orilla SE de la laguna rellena, 6°23'N, 72°16'W, 3 Mar 1973, A.M. Cleef 8762 (COL, US); páramo de la Sarna entre Sogamoso y Vado Hondo, 5°35'N, 72°51'W, 5 Apr 1973, A.M. Cleef 9411a (COL); Nevado de Cocuy, alto valle de Las Lagunillas, 6°21'N, 72°19'W, 12 Sep 1938, J. Cuatrecasas 1486 (COL, US); Norte de Santander: Chitagá, corregimiento Presidente, vereda Presidente, alrededores de la quebrada El Salado, en el ascenso a la terraza pantanosa entre las lagunas El Salado y El Tambor, 7°0'N, 72°42'W, 22 May 2007, D.I. Capacho-Navia et al. 243 (COL); Chitagá, corregimiento Presidente, vereda Presidente, laguna El Tambor, sobre margen al costado SE, 7°0'N, 72°42'W, 15 Mar 2007, D.I. Capacho-Navia et al. 362 (COL [mixed with Werneria pygmaea ]); Cordillera Oriental, páramo del Almorzadero, vertiente norte, 6°59'N, 72°44'W, 28 Nov 1941, J. Cuatrecasas 13505 (COL [mixed with W. pygmaea ], US); Santander: páramo del Almorzadero, 6°59'N, 72°44'W, 17 Nov 1978, J. Aguirre & A.M. Cleef 880 (COL); Cordillera Oriental, páramo de Almorzadero, on road between Chitagá and Cerrito, about half way to Boquerón, 6°56'N, 72°40'W, 31 Dec 1959, H.G. Barclay & P. Juajibioy 10363 (COL); páramo de Almorzadero, on road between Chitagá and Cerrito, approx. 7 km S of highest point of paramo, 6°59'N, 72°40'W, 31 Dec 1959, H.G. Barclay & P. Juajibioy 10370 (COL [mixed with W. pygmaea ], US); Alto del Almorzadero, vertiente sur, 6°58'N, 72°43'W, 20 Jul 1940, J. Cuatrecasas & H. García Barriga 10012 (COL, US); páramo del Almorzadero, km 50-51, 7°0'N, 72°44'W, 20 Sep 1969, J. Cuatrecasas & L. Rodríguez 27887 (COL, US).

Figures

Figure 12. Distribution map of Xenophyllum rigidum (left hand), X. crassum subsp. crassum (right hand, closed triangle), and X. crassum subsp. orientale (right hand, open circle).