Xenophyllum staffordiae (Sandwith) V.A.Funk, Novon 7(3): 240. 1997.

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

21. Xenophyllum staffordiae (Sandwith) V.A.Funk, Novon 7(3): 240. 1997.

Werneria staffordiae Sandwith, Hooker’s Icon. Pl. 35: tabula 3424. 1940. Type. Peru. Puno: San Antonio de Esquilache, 4725 m, 14 May 1937, D. Stafford 734 (lectotype: K-000527744 (digital image!), designated as “holotype” by Funk (1997a: 240); isolectotypes: K s.n.!, BM s.n.!, F-1508962!).

Description.

Shrubby plant. Rhizomes ca. 6 × 0.7-1 cm, horizontal to oblique, glabrous. Stems 30-60 cm tall, branched, glabrous, with leaves restricted to the upper part. Leaves imbricate, extending into a sheath-like base glabrous or with long silky trichomes; leaf laminas 6.8-9.3 × 3.2-3.7 mm, spatulate (finger-like at the apex), at least 12-divided at the apex, with all divisions similar in length, entire, elliptical to terete upwards in cross section, glabrous or floccose-lanate, 1-nerved above (barely visible), 1-nerved beneath, somewhat fleshy, matte; divisions ca. 1.5 mm long, rounded to truncate. Capitula radiate, rather nodding, subsessile to shortly pedunculate (up to 5 mm long, sometimes bearing 1 to 2 oblong bracts that reach the involucre). Involucres 8.6-10.5 × 8.2-10 mm, cupuliform; involucral bracts 11 to 20, 4.3-5 × 2.5-2.8 mm, obtuse at the apex, greenish to slightly purplish. Ray florets 15 to 28; corollas 6.4-8.3 × 0.8-1.1 mm, unconspicuously veined, subentire to 3-toothed at the apex, not surpassing the involucre, pale yellow. Disc florets 36 to 81; corollas 7.4-9.2 mm long, yellowish; style branches truncate with a crown of sweeping trichomes, yellowish. Achenes 3.3-3.6 × 0.9-1 mm, cylindrical, 7 to 9-ribbed, glabrous; pappus 8.2-14.2 mm long, barbellate, whitish. Chromosome number unknown. Fig. 26 .

Additional iconography.

Sandwith (1940: tabula 3424, sub Werneria staffordiae ); Beltrán (2016: 359, fig. 3D, as photo).

Distribution and habitat.

Endemic to Peru (Arequipa, Cusco, Huánuco, Lima, Moquegua, Puno). It grows in rocky outcrops, scree slopes, and exposed grasslands of the subhumid puna ecoregion, between elevations of 3900-5200 m (Fig. 27 ).

Xenophyllum staffordiae is known from central and southern Peru, however, a remarkable gap exists between these two distribution centers. No collections were studied from Apurímac, Ayacucho, and Huancavelica.

Phenology.

Flowering from March to December.

Etymology.

The epithet staffordiae honors the English field botanist Dora Stafford, who collected in Peru in the 1930s.

Notes.

This is a shrub with 30-60 cm tall stems that have glabrous or floccose-lanate finger-like leaves, with at least 12 divisions at the apex. The divisions are similar in length, ca. 1.5 mm deep. It is characterized by its capitula that tend to be nodding as the plant ages, with 15 to 28 ray florets with pale yellow corollas that do not surpass the involucre. As in the case of X. poposa , we observed a few ray florets with staminodes (Fig. 26E ). It only might be confused with X. dactylophyllum (see comments under it).

It should be mentioned that the elevation indicated on the isolectotype at F is 16000 feet, which slightly differs from that indicated on the lectotype (15500 feet). We believe that such mismatch is not a major reason for excluding it from the type material.

Additional specimens examined.

Peru. Arequipa: La Unión, Cotahuasi, 15°14'S, 72°52'W, 30 Jun 2002, F. Cáceres 2806 (HUSA); Caylloma, Chivay, bajada a Chivay, 15°42'S, 71°35'W, 25 Oct 1988, E. Linares 260 (CUZ, USM); La Unión, entre Solimana y Ccoropuna, base, 15°27'S, 72°46'W, 25 Apr 1967, C. Vargas 19541 (CUZ, US); Castilla, Tapay, cerro Blanco, Apacheta, 13 Sep 2011, N. Vega 1734 (USM); Cusco: Espinar, Yauri, 14°48'S, 71°24'W, 20 Jun 1944, C. Vargas 4382 (CUZ, F); Huánuco: Huánuco viejo, 9°52'S, 76°49'W, 4 Oct 1968, I. Meza s.n. (USM); Lima: Huarochirí, cordillera de Carampoma, 11°39'S, 76°31'W, Dec 1929, N. Esposto s.n. (MOL, USM); Huarochirí, San Damián, abra entre Chanape y la comunidad Checca, 11°55'S, 76°15'W, 14 Jul 2013, P. Gonzáles & B. Brito 2667 (USM); Canta, Lachaqui, más arriba de la laguna de Quinán, camino hacia Carampoma ( Huarochirí), 11°35'S, 76°34'W, 20 May 1995, A. Granda 1496 (MOL, US); Canta, cerca a Canta Mishquipuquio, 11°34'S, 76°33'W, 10 Aug 1949, S. Sánchez 44 (USM); Canta, Lachaqui, arriba de laguna Quinan, 11°35'S, 76°34'W, 30 Jun 2000, G. Vilcapoma 5194 (USM); Huarochirí, San Juan de Iris, alrededores de Tuktococha, 11°42'S, 76°25'W, 18 Aug 1993, G. Yarupaitán & J. Albán 1012 (US, USM); Moquegua: General Sánchez Cerro, Yunga, Perusa, 16°11'S, 70°37'W, 3 Mar 2018, D. Montesinos & J. Calvo 5957 (HSP); Puno: cerro Ichuasi, Caccachara, ca. 50 miles SW of Ilave, 18 Nov 1946, P. Oliver & A. Pearson 86 (US); Crestón, San Antonio [de Esquilache], 1 Jul 1937, T.G. Tutin 1201 (BM).

Figures

Figure 26. Xenophyllum staffordiae A habit B leaf C capitulum D ray corolla and style E ray corolla and style (notice staminodes) F disc corolla and style branches G disc corolla and stamens (vertically sectioned, style removed) H style I immature achene with pappus. All details drawn from Oliver & Pearson 86 (US) except for A (drawn from Stafford 734, K). Illustration by Alice Tangerini.

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