17. Xenophyllum pseudodigitatum (Rockh.) V.A.Funk, Novon 7(3): 240. 1997.

Werneria pseudodigitata Rockh., Bot. Jahrb. Syst. 70: 288. 1939. Type. Argentina. Salta: Umgebung des Nevado del Castillo, 3050-4570 m, 19/23 Mar 1873, P.G. Lorentz & G. Hieronymus 96 (lectotype: GOET s.n.!, designated by Funk (1997a: 240); isolectotypes: CORD-00005638 (digital image!), K s.n.!).

Werneria castillensis Hieron., nom. nud. in sched. (Turland et al. 2018, ICN Art. 38.1).

Description.

Suffruticose plant, forming clumps of erect stems. Rhizomes 5-8 × 0.4-0.6 cm, horizontal to oblique, glabrous. Stems 5-12 cm tall, simple or branched, glabrous, usually with leaves restricted to the upper part. Leaves imbricate, extending into a glabrous sheath-like base; leaf laminas 6-9.6 × 2-3.8 mm, linear-spatulate (broadened upwards), 3-forked at the apex (incision depth 1/8-1/7 of the total length), entire, sometimes with some minute cilia in the lower half, flat to elliptic or almost terete upwards in cross section, glabrous, 1-nerved above (barely visible), 1-nerved beneath, fleshy, matte; leaf lobes 1.3-2.6 × 1-1.6 mm, acute to mucronate (rarely notched). Capitula radiate, erect, sessile. Involucres 7-8.4 × 5.2-8 mm, cupuliform; involucral bracts 10 to 11, 3.4-3.9 × 2-2.8 mm, obtuse at the apex, greenish. Ray florets 20 to 25; corollas 7.1-8.2 × 1-1.2 mm, 3 to 4-veined, subentire to 3-toothed at the apex, conspicuously surpassing the involucre, white. Disc florets 29 to 33; corollas 4.2-5.1 mm long, yellowish; style branches penicillate, purplish. Achenes 2.3-2.5 × 0.5-0.7 mm, cylindrical, 7 to 9-ribbed, glabrous; pappus 5.2-7.1 mm long, barbellate, whitish. Chromosome number unknown. Fig. 22.

Additional iconography.

Cabrera (1978: 473, fig. 200A-F, sub Werneria pseudodigitata); Funk (1997a: 237, fig. 1C); Freire and Ariza-Espinar (2014: 228, X. pseudodigitatum A-E).

Distribution and habitat.

Endemic to Argentina (Jujuy, Salta). It grows in rocky slopes on rather wet soils of the dry puna ecoregion, between elevations of 3700-5125 m (Fig. 23).

Phenology.

Flowering from January to May.

Etymology.

The epithet pseudodigitatum refers to the resemblance between this species and X. digitatum . It probably responds to the fact that both species have 3-forked leaves.

Notes.

Xenophyllum pseudodigitatum is characterized by its 3-forked leaves. The leaf lobes are 1.3-2.6 mm long, which represents 1/8-1/7 of the total leaf length, and they are acute to mucronate at the apex (rarely notched); on living plants, they are noticeably spread out. The involucre length ranges from 7 to 8.4 mm and has 10 to 11 involucral bracts. The radiate capitula are composed of 20 to 25 ray florets and 29 to 33 disc florets.

This is a narrow endemic species to northwestern Argentina that has erroneously been reported from northern Chile (Ricardi and Marticorena 1966; Freire and Ariza-Espinar 2014; Moreira-Muñoz et al. 2016) and southern Peru ( Gonzáles et al. 2016). All these records are confusions with X. digitatum . In order to avoid further misidentifications, the following characters should be studied: leaf lobe length (1.3-2.6 mm in X. pseudodigitatum vs. 3.6-5.9 mm in X. digitatum), involucre length (7-8.4 mm in X. pseudodigitatum vs. 12.1-16.7 mm in X. digitatum), number of involucral bracts (10 to 11 in X. pseudodigitatum vs. 12 to 13 in X. digitatum), ray corolla length (7.1-8.2 mm in X. pseudodigitatum vs. 9.2-14.1 mm in X. digitatum), and number of disc florets (29 to 33 in X. pseudodigitatum vs. 49 to 63 in X. digitatum). Their distribution areas do not overlap.

Additional specimens examined.

Argentina. Jujuy: Humahuaca, mina Aguilar, 23°12'S, 65°43'W, 11 Jan 1968, A.L. Cabrera et al. 19009 (SI); mina Aguilar, abra Aguilar, 23°9'S, 65°42'W, 19 Feb 1969, A.L. Cabrera, J. Crisci & R. Kiesling 19843 (C); Volcán, abra del Córdoba, 23°53'S, 65°34'W, Feb 1922, L. Castillón 1761 (LIL); Estación Volcán, 23°53'S, 65°34'W, Feb 1920, L. Castillón 7140 (A, F); El Aguilar, oberhalb, 5° E. Hochandine Polsterflur, 23°11'S, 65°42'W, 1 Feb 1971, H. Ellenberg 4295 (US); Tilcara, subida a la abra de Remate, 23°32'S, 65°16'W, 15 Feb 1953, A. Fiebrig s.n. (LIL); near mina La Esperanza, just before entrance to town of El Aguilar, side rd. to mina La Esperanza, 23°10'S, 65°43'W, 9 Mar 1993, V.A. Funk & L. Katinas 11157 (US); rd. to mina La Esperanza, 23°10'S, 65°43'W, 9 Mar 1993, V.A. Funk & L. Katinas 11169 (US); Humahuaca, mina Aguilares, arriba de la mina, 23°11'S, 65°43'W, 29 Mar 1952, E. Petersen & J.P. Hjerting 159 (C, LIL); Humahuaca, subida al cerro Aguilar, 23°11'S, 65°43'W, 17 Jan 1953, H. Sleumer 3448 (LIL); Humahuaca, cerro Aguilar, cumbre, 23°11'S, 65°43'W, 17 Jan 1953, H. Sleumer 3452 (LIL); Tilcara, cumbre del cerro, 23°36'S, 65°28'W, 3 May 1927, S. Venturi 6254 (US).