Xenophyllum lorochaqui J.Calvo & V.A.Funk, PhytoKeys: 139: 34. 2020.

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

14. Xenophyllum lorochaqui J.Calvo & V.A.Funk, PhytoKeys: 139: 34. 2020.

Type.

Argentina. Catamarca: El Cajón, Negroara, 15 Jan 1914, L. Castillón 3365 (holotype: LIL-26677!; isotypes: BM s.n.!, BR s.n.!, US-00622893!, W-334!).

Description.

Suffruticose plant, forming clumps of erect stems. Rhizomes 5-10 × 0.6-0.8 cm, horizontal to oblique, glabrous. Stems 10-20 cm tall, branched, glabrous, usually with leaves restricted to the upper part. Leaves imbricate, extending into a sheath-like base glabrescent or with evanescent arachnoid trichomes; leaf laminas 7.9-11.5 × 2.3-2.7 mm, linear, broadened at the apex, 3-notched at the apex, with the central lobe longer than lateral ones, entire, curved forwards in cross section, glabrous, unconspicuously nerved on both faces, fleshy, matte; central leaf lobe 1-1.6 mm long (lateral ones 0.5-0.8 mm long), 1.3-1.6 mm wide at the maximum width point, entire or barely notched, obtuse. Capitula radiate, erect, sessile. Involucres 10.3-10.9 × 6.6-8.7 mm, cupuliform; involucral bracts ca. 13, 5.9-7 × 1.4-2.5 mm, obtuse at the apex, greenish. Ray florets 26 to 39; corollas 8.3-9.2 × 1.1-1.4 mm, 4-veined, subentire to 3-toothed at the apex, conspicuously surpassing the involucre, white. Disc florets 40 to 57; corollas 4.2-5.5 mm long, yellowish; style branches truncate with a crown of sweeping trichomes, yellowish. Achenes 2.5-3.1 × 0.7-0.9 mm, cylindrical, 8 to 9-ribbed, glabrous; pappus 4.3-6.1 mm long, barbellate, whitish. Chromosome number unknown. Figs 19A , 21 .

Distribution and habitat.

Endemic to Argentina (Catamarca, Jujuy, Salta, Tucumán). This species grows in exposed rocky slopes and on bare soils of the dry puna ecoregion, between elevations of 3500-5000 m (Fig. 20 ).

Phenology.

Flowering from January to March.

Etymology.

The epithet lorochaqui is the vernacular name of this plant and it means parrot’s foot ( “loro” from Spanish: parrot; “chaqui” from Quichua: foot). It probably responds to the resemblance of the leaves with a parrot’s foot.

Notes.

Xenophyllum lorochaqui can be identified by the glabrous erect stems 10-20 cm tall (usually only bearing leaves in the upper part), leaf lamina 7.9-11.5 mm long, leaf apex 3-notched with the central lobe entire or barely notched and longer than the lateral ones, involucre with ca. 13 involucral bracts, and by displaying 26 to 39 ray florets with white corollas.

This species shows morphological affinities with X. incisum , X. dactylophyllum , and X. poposa . The differences against X. incisum are the leaf lamina length (3.2-7.3 mm vs. 7.9-11.5 mm in X. lorochaqui ), the length of the leaf apex lobes (similar among them vs. central lobe longer than lateral ones in X. lorochaqui ), the involucre length (6.4-8.3 mm vs 10.3-10.9 mm in X. lorochaqui ), the involucral bract number (8 to 9 vs. ca. 13 in X. lorochaqui ), and the ray floret number (8 to 13 vs. 26 to 39 in X. lorochaqui ). With regard to X. dactylophyllum , the leaf apex is at least 9-divided (finger-like) with the primary division extending deeper than the subsequent ones, whereas in X. lorochaqui the leaf apex is 3-notched with the central lobe longer than lateral ones. From X. poposa , the distinguishable characters are the stem indumentum (arachnoid in X. poposa vs. glabrous in X. lorochaqui ), the leaf lamina length (2.5-7.1 mm in X. poposa vs. 7.9-11.5 mm in X. lorochaqui ), the involucral bract number (8 to 9 in X. poposa vs. ca. 13 in X. lorochaqui ), and the ray floret number (8 to 11 in X. poposa vs. 26 to 39 in X. lorochaqui ). Among these species, the distribution area of X. lorochaqui partially overlaps with that of X. incisum and X. poposa .

Additional specimens examined.

Argentina. Jujuy: Tumbaya, cerro Moreno, 23°46'S, 65°44'W, 7 Feb 1929, S. Venturi 9289 (US); Salta: Cafayate, sierra de los Quilmes, 26°11'S, 66°4'W, 28 Jan 1943, A. Castellanos s.n. (BA); abra del Gallo, ca. 40 km al SW de S. Antonio de los Cobres, en el camino a Pastos Grandes, 24°20'S, 66°30'W, 17 Dec 1946, A. Krapovickas 3215 (LIL, SI); nevado del Cajón, 26°8'S, 66°13'W, 1 Mar 1914, D. Rodríguez 1382 (BA, BR); Tucumán: cerro Muñoz, 26°52'S, 65°50'W, Jan 1916, L. Castillón s.n. (BR [mixed with X. poposa ]); Tafí, cumbres de San José (La Mina), 26°41'S, 65°40'W, Mar 1933, Díaz s.n. (GH, LIL); Tafí, cumbre de Chasquivil, 26°41'S, 65°40'W, 12 Jan 1945, D. Olea 252 (LIL); Chicligasta, estancia Las Rosas, 15 Jan 1927, S. Venturi 6342 (US); Tafí, sierra del Cajón, Los Chuscos, 7 Feb 1926, S. Venturi 6647 (US).

Figures

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.

Figure 20. Distribution map of Xenophyllum poposa (left hand), X. lorochaqui (right hand, closed triangle), and X. rosenii (right hand, open circle).

Figure 21. Xenophyllum lorochaqui A habit B stem apical part and capitulum C adaxial leaf surface (left hand) and vertical leaf profile (right hand) D capitulum E ray floret (pappus removed) F disc corolla G stamen H style. All details drawn from Castellanos s. n. (BA) except for A, B (drawn from Diaz s. n., GH). Illustration by Alice Tangerini.