Xenophyllum roseum (Hieron.) 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

4. Xenophyllum roseum (Hieron.) V.A.Funk, Novon 7(3): 240. 1997.

Werneria rosea Hieron., Bot. Jahrb. Syst. 28(5): 648. 1901. Werneria humilis var. rosea (Hieron.) Rockh., Bot. Jahrb. Syst. 70: 295. 1939. Type. Ecuador. Azuay: páramo del Cajas, W Andes of Cuenca, 3800-4300 m, [without date], F.C. Lehmann 5687 (lectotype: K-000527743 (digital image!), designated by Funk (1997a: 240); isolectotype: US-00037306 (fragment!)).

Werneria purpurea Spruce ex Rockh., Bot. Jahrb. Syst. 70: 295. 1939, nom. inval. pro syn. ( Turland et al. 2018, ICN Art. 36.1).

Description.

Suffruticose plant, forming dense mats or hummocks, with rhizome-like stems up to 6.5 cm long covered with matted lanate indumentum and leaf bases, rather erect, simple or branched from the base. Stems 1.5-2 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 4.6-10.6 × 1.3-1.5 mm, linear, obtuse, callous-like tipped at the apex (the young ones usually bearing a quickly deciduous arista up to 0.5 mm long), entire, elliptical to almost terete in cross section (rather flat when dried), glabrous, unconspicuously nerved above, 1-nerved beneath (barely visible; in dried specimens the nerves are noticeable on both faces), fleshy, matte, papillose. Capitula radiate, erect, sessile. Involucres 10-12 × 7.9-8 mm, cupuliform; involucral bracts ca. 13, 5.5-7.6 × 1.6-2 mm, acute at the apex, greenish, purple-edged. Ray florets 11 to 13; corollas 11.8-19 × 2.5-3 mm, 4-veined, subentire to 3-toothed at the apex, conspicuously surpassing the involucre, pink. Disc florets 28 to 34; corollas 5.7-8 mm long, yellowish; style branches penicillate, yellowish. Achenes cylindrical, white-villous with trichomes ca. 0.5 mm long (immature); pappus ca. 7 mm long, barbellate, whitish. Chromosome number unknown. Fig. 8 .

Distribution and habitat.

Endemic to Ecuador (Azuay, Cañar, Loja). It grows in moist grasslands and exposed places of the paramo ecoregion, between elevations of 3650-4275 m (Fig. 9 ).

Xenophyllum roseum is a narrow endemic species only known from El Cajas National Park (Azuay) and the Culebrillas Lagoon ( Cañar). A single collection from Loja (Jameson s.n., US) would also support its presence in this province. However, the label information does not provide a precise locality ("province of Loxa"), and therefore, it has not been represented on the map. New collections are required to confirm that X. roseum thrives in Loja.

Phenology.

Flowering from August to March.

Etymology.

The adjective roseus -a -um means rose-like, rose-colored, pink-colored. It refers to the characteristic pink ray corollas of this species.

Notes.

Xenophyllum roseum is well defined by its linear, stellate-imbricate leaves that usually have the leaf lamina spreading at nearly 90° from the sheath-like base, and by the obtuse leaf apex that usually bears a quickly deciduous arista when young. The achenes are covered with a white-villous indumentum and the ray corollas are pink. This latter character makes this species unique within the genus. The color is very noticeable on living plants but in old dried specimens it might be less obvious, and therefore, somewhat equivocal for identification purposes.

It is morphologically similar to X. humile and X. sotarense . From the former species, it differs in the ray corolla length and color (11.8-19 mm, pink in X. roseum vs. 4.2-12.2 mm, white in X. humile ), disc corolla length and color (5.7-8 mm, yellowish in X. roseum vs. 3.1-5 mm, whitish in X. humile ), and achene indumentum (white-villous in X. roseum vs. glabrous in X. humile ). The deciduous arista that usually adorns the young leaves of X. roseum also helps to differentiate it from X. humile . With respect to X. sotarense , the differences are detailed under this latter species. Among the aforementioned species, X. roseum overlaps its distribution area with that of X. humile .

Additional specimens examined.

Ecuador. Azuay: road Cuenca-Angas, 28 Dec 1976, J.D. Boeke 650 (QCA, US); P.N. Cajas, cerca de la laguna de Soldados, 2°54'S, 79°18'W, 17 Nov 2000, L. Endara & M. Nonhebel 554 (QCA); Cajas, ca. 30 km W of Sayausí, at pass NE toward highest peak, 2°46'S, 79°14'W, 23 Oct 1995, V.A. Funk & X. Montezuma 11426 (HA, QCA, US); 5 km W of Soldados on Cuenca-San Joaquín-Angus rd., ca. 100 m up slopes N of rd. toward large laguna, near laguna Estrellas Cocha, 2°54'S, 79°15'W, 24 Oct 1995, V.A. Funk & X. Montezuma 11441 (US); W of Cuenca on gravel road between Soldados and Balao (hwy 25), laguna Estrellas Cocha, 6 km W of Arch at Soldados Park entrance, 2°54'S, 79°15'W, 18 Apr 2018, V.A. Funk & J.M. Bonifacino 14033 (US); Assuay, Oct 1864, W. Jameson s.n. (E); P.N. Cajas, páramo de Soldados, road Cuenca-San Joaquín-Soldados, at the pass above Soldados, 2°54'S, 79°17'W, 8 Jan 2000, P.M. Jørgensen et al. 1738 (HA, QCNE, US); P.N. Cajas, road Cuenca-Sayausí-Molleturo, at the pass, km 38.4, 2°46'S, 79°14'W, 3 Jan 2000, P.M. Jørgensen, C. Ulloa & E. Narváez 2083 (HA, US); Cuenca, Sayausí, Tres Cruces, 2°46'S, 79°14'W, 13 Oct 2017, D. Minga, M. Jiménez & N. Guzmán 3242 (HA); área nacional de recreación Cajas, Totorococha-Mazan valley, 2°53'S, 79°10'W, 12 Sep 1987, P.M. Ramsay & P.J. Merrow-Smith 448 (QCNE); Andibus Ecuadorensibus, in repisis m. Azuay, Aug 1857/9, R. Spruce 6013 (BM, C, E, F [fragment], GH, GOET, K, LE, NY, P, TCD, W); P.N. Cajas, km 35.7 redondel Cuenca-Molleturo, en el paso, sendero Paragüillas, 2°46'S, 79°14'W, 13 Jan 2003, C. Ulloa, P.M. Jørgensen & X. Clavijo 1173 (HA); Cuenca, Sayausí, P.N. Cajas, Tres Cruces, sendero del estacionamiento hacia arriba, 2°46'S, 79°14'W, 28 Apr 2015, C. Ulloa et al. 2534 (HA); Cañar: El Tambo, camino de la laguna Culebrillas hasta Ingapirca, cerca de la comunidad de Cajontambo, 2°26'S, 78°52'W, 11 Mar 2009, D. Minga & F. Nugra 1594 (HA); Loja: province of Loxa, Sep 1864, W. Jameson s.n. (US).

Figures

Figure 8. Xenophyllum roseum A habit B capitulum C adaxial leaf surface D detail of leaf surface E ray corolla and style 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 Jameson s. n. (US) except for A (drawn from Funk & Montezuma 11441, US). Illustration by Alice Tangerini.

Figure 9. Distribution map of Xenophyllum sotarense (left hand, closed triangle), X. roseum (left hand, open circle), and X. funkianum (right hand).