Xenophyllum incisum (Phil.) 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

12. Xenophyllum incisum (Phil.) V.A.Funk, Novon 7(3): 239. 1997.

Werneria incisa Phil., Anales Mus. Nac., Santiago de Chile 8: 41. 1891. Type. Chile. Antofagasta: inter Copacoya et Inacaliri, 19 Feb 1885, F. Philippi s.n. (lectotype: Philippi’s collection at SGO as the first-step lectotype, designated as “holotype” by Funk (1997a: 239); SGO-060388! as the second-step lectotype, designated here; isolectotypes: LP-002607 (digital image!), SGO-000006431 (ruined!)).

Description.

Suffruticose plant, forming clumps of rather decumbent stems. Rhizomes 4-8 × 0.4-0.6 cm, horizontal to oblique, glabrous. Stems 4-8 cm tall, simple or branched, glabrous, with leaves rather uniformly arranged along it. Leaves imbricate, extending into a glabrous sheath-like base; leaf laminas 3.2-7.3 × 1.4-1.9 mm, linear-oblong, 3-notched at the apex, sometimes with the central lobe wider than lateral ones (rarely subentire), entire, obtusely triangular to slightly curved forwards in cross section, glabrous, unconspicuously nerved above, 1-nerved beneath, fleshy, matte; leaf lobes 0.5-1 × 0.5-0.6 mm, obtuse to truncate. Capitula radiate, erect, sessile. Involucres 6.4-8.3 × 4.6-6.1 mm, cupuliform; involucral bracts 8 to 9, 3.1-4.3 × 1.1-2.6 mm, obtuse at the apex, greenish. Ray florets 8 to 13; corollas 6.2-8.9 × 0.6-1.2 mm, 2 to 4-veined, subentire to 3-toothed at the apex, conspicuously surpassing the involucre, white. Disc florets 26 to 37; corollas 4.4-5 mm long, pale yellow to creamy; style branches truncate with a crown of sweeping trichomes, purplish. Achenes 2.3-2.4 × 0.8-0.9 mm, cylindrical, ca. 8-ribbed, glabrous; pappus 4.8-8 mm long, barbellate, whitish. Chromosome number unknown. Fig. 19C .

Additional iconography.

Cabrera (1978: 473, fig. 200G, H, sub Werneria incisa ).

Distribution and habitat.

Restricted to northern Chile, northwestern Argentina, and southwestern Bolivia. Argentina (Jujuy, Salta), Bolivia ( Potosí), Chile (Antofagasta). This species grows along the banks of salt lagoons and desert plains with a certain humidity of the dry and desertic puna ecoregions, between elevations of (2600-)3500-4900 m (Fig. 17 ).

Phenology.

Flowering from October to March.

Etymology.

The epithet incisum means sharply and deeply cut into, which describes the leaf apex of this species. However, its leaf apex is rather notched (shallowly cut into).

Notes.

This species can be properly identified by the combination of the following characters: rather decumbent, 4-8 cm tall, glabrous stems, linear-oblong leaf lamina, 3-notched leaf apex with truncate lobes (rarely subentire), 8 to 9 involucral bracts, 8 to 13 ray florets with white corollas conspicuously surpassing the involucre, and glabrous achenes.

Xenophyllum incisum is somewhat variable in leaf apex shape. Typical forms have 3-notched leaf apex, usually with the central lobe wider than lateral ones, but in some specimens the apex is barely notched or even subentire (e.g., Moreira-Muñoz 298, CONC; Arroyo et al. 97315, CONC). In these specimens, however, the leaf apex is truncate and slightly curved forwards as typically in the species. Similarly, we studied one specimen having the leaf apex with each lobe 3-notched ( Villagrán et al. 9321, CONC).

This species has morphological affinities with X. lorochaqui J.Calvo & V.A.Funk, X. weddellii (see comments under these species), and X. poposa . With regard to the latter species, the main and unequivocal character that allows a proper identification is the stem indumentum (glabrous in X. incisum vs. arachnoid in X. poposa ). The characters concerning the leaf apex have traditionally been used for discriminating among these species, however, they are barely useful because X. poposa also shows high variability in leaf apex (see further comments under it). A rather useful character is the leaf section, which is obtusely triangular to slightly curved forwards in X. incisum vs. terete or almost so in X. poposa . The sheath-like base is also more broadened in X. incisum .

The holotype designation by Funk (1997a) is corrected to lectotype because the gathering indicated by Philippi in the protologue is not represented by a single specimen. Moreover, a second-step lectotypification is made because two specimens of this gathering were found at SGO.

Additional specimens examined.

Argentina. Jujuy: Susques, a 30 km de Jama, entre Jama y Susques, 23°28'S, 66°56'W, 22 Jan 2000, A. Bardón s.n. (LIL); Achibarca, 23°41'S, 66°52'W, 11 Mar 1927, A. Castellanos s.n. (BA); bolsón del Vilama, 22°35'S, 66°56'W, 28 Sep 1939, J.S. Collan 44 (LIL); Salta: Tusle [Tuzgle], pr. mina Concordia, 24°10'S, 66°24'W, 29 Oct 1901, R.E. Fries 707 (US); abra del Gallo, ca. 40 km al SW de S. Antonio de los Cobres, en el camino a Pastos Grandes, 24°21'S, 66°30'W, 17 Dec 1946, A. Krapovickas 3209 (K, LIL). Bolivia. Potosí: Sud Lípez, laguna Verde 36 km hacia laguna Colorada, 22°30'S, 67°37'W, 28 Apr 2000, S.G. Beck 27510 (LPB); Nor Lípez, ruta laguna Hedionda-Alota, 23 km de laguna Hedionda, 21°32'S, 67°52'W, 23 Sep 2006, S.G. Beck 32410 (LPB, USM); Sud Lípez, laguna Pastos Grandes, al E de la laguna, 21°36'S, 67°44'W, 20 May 1989, E. García 1101 (LPB, USM); Sud Lípez, cerro Tapaquillcha, 21°31'S, 67°53'W, 13 Apr 1980, M. Liberman 206 (LPB). Chile. Antofagasta: El Loa, salar de Quisquiro, 23°17'S, 67°21'W, Jan 1997, G. Arancio 10676 (CONC); El Loa, sector N del salar de Aguas Calientes, 23°4'S, 67°22'W, Jan 1997, G. Arancio 10697 (CONC); El Loa, salar de Aguas Calientes, 23°27'S, 67°37'W, 17 Mar 1992, G. Arancio 92-341 (CONC); El Loa, camino de San Pedro de Atacama a paso Jama, quebrada Llano Vilama, 22°53'S, 68°6'W, 6 Apr 1997, M. Arroyo, L. Cavieres & A. Humaña 97217 (CONC); El Loa, ojos del río Salado, pequeño salar en el extremo N, 23°21'S, 67°22'W, 8 Apr 1997, M. Arroyo, L. Cavieres & A. Humaña 97276 (CONC, MA); El Loa, salar Quisquiro, lado E, 23°18'S, 67°18'W, 8 Apr 1997, M. Arroyo, L. Cavieres & A. Humaña 97315 (CONC); El Loa, cerro Nevados de Poquis, ladera SO, 23°4'S, 67°4'W, 9 Apr 1997, M. Arroyo, L. Cavieres & A. Humaña 97373 (CONC); El Loa, salar de Aguas Calientes, 23°7'S, 67°26'W, 11 Apr 1997, M. Arroyo, L. Cavieres & A. Humaña 97463 (CONC); El Loa, laguna El Chivato Muerto, 23°26'S, 67°26'W, 14 Feb 1994, G. Baumann 352 (CONC); salar de Ascotán, 21°31'S, 68°20'W, 19 Jan 1957, F. Behn 19596 (CONC); Antofagasta, Loa, Toconao, N del salar de Quisquiro, quebrada de Taina, 23°11'S, 67°19'W, 4 Mar 2019, J. Calvo 7914 (CONC, SGO); Antofagasta, Loa, San Pedro de Atacama, Machuca-El Tatio, ca. 6.2 km al S de El Tatio, 22°23'S, 68°1'W, 5 Mar 2019, J. Calvo 7924 (SGO); salar de Ascotán, along the margins of the salar, 21°2'S, 68°28'W, 4 Mar 2014, V.A. Funk, M. Diazgranados & J.M. Bonifacio 13077 (US); salar de Ascotán, along the margins of the salar, 21°2'S, 68°28'W, 4 Mar 2014, V.A. Funk, M. Diazgranados & J.M. Bonifacio 13078 (US); salar de Tara, 23°2'S, 67°20'W, 7 Dec 1988, A. Hoffmann s.n. (CONC); Cebollar, entre el salar de Ascotán y el salar de San Martín, 21°26'S, 68°23'W, 20 Feb 1964, C. Marticorena, O. Matthei & M. Quezada 405 (CONC); vegas del río Zapaleri, 22°57'S, 67°13'W, 18 Dec 1996, A. Moreira-Muñoz 257 (CONC); borde W salar de Tara, 23°0'S, 67°16'W, 18 Dec 1996, A. Moreira-Muñoz 289 (CONC); borde sur salar de Tara, 22°59'S, 67°18'W, 18 Dec 1996, A. Moreira-Muñoz 298 (CONC); Mucar [laguna], 23°21'S, 67°6'W, 14 Dec 1965, L. Peña 5 (CONC); Machuca, 22°35'S, 68°3'W, 18 Feb 1885, F. Philippi s.n. (GB); Tarapacá [without locality and date, probably a duplicate of Philippi 18 Feb 1885], F. Philippi s.n. (US); El Loa, San Pedro de Atacama, Socaire, laguna Sico, 23°52'S, 67°19'W, 5 Apr 1997, S. Teillier 4058 (CONC); El Loa, salar de Ascotán, 21°31'S, 68°20'W, Feb 1997, S. Teillier 4226 (CONC); El Loa, trayecto entre Talabre y laguna Lejía, 23°21'S, 67°48'W, 2 Apr 1998, C. Villagrán, F. Hinojosa & C. Latorre 9321 (CONC).

Figures

Figure 17. Distribution map of Xenophyllum juniperinum (left hand), X. weddellii (right hand, closed triangle), and X. incisum (right hand, open circle).

Figure 19. Detail of leaves and capitulum A Xenophyllum lorochaqui, drawn from Castellanos s. n. (BA) B X. poposa, drawn from Cardenas 362 (US) C X. incisum, drawn from Funk et al. 13078 (US). Illustration by Alice Tangerini.