Xenophyllum funkianum J.Calvo, PhytoKeys: 139: 30. 2020.

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

5. Xenophyllum funkianum J.Calvo, PhytoKeys: 139: 30. 2020.

Type.

Ecuador. Chimborazo: Mt. Chimborazo area, at the end of Polylepis road and beginning of hike to Polylepis forest, 1°31 ’50’’ S, 78°52 ’55’’ W, 4233 m, 20 Apr 2018, V.A. Funk & J.M. Bonifacino 14059 (holotype: US!; isotypes: MO!, QCA!).

Description.

Suffruticose plant, forming lax mats, with rhizome-like stems 20-35 cm long covered with arachnoid indumentum and leaf base remnants resembling paleae, horizontal, creeping, simple or branched from the base. Stems 2-3 cm tall (aerial part), arachnoid. Leaves imbricate, extending into a sheath-like base that bears arachnoid trichomes; leaf laminas 5.3-7.8 × 0.8-0.9 mm, linear, rather acute, callous-like tipped at the apex, entire, elliptical in cross section, glabrous, unconspicuously nerved above, 1-nerved beneath (only visible in the lower third), fleshy, shiny, papillose. Capitula radiate, erect, sessile. Involucres 9-11 × 5-7 mm, cupuliform; involucral bracts 13 to 14, 4.7-6.9 × 1-1.7 mm, acute at the apex, dark-burgundy. Ray florets 12 to 13; corollas 8.9-11.6 × 2.3-3 mm, 4-veined, subentire to 3-toothed at the apex, conspicuously surpassing the involucre, white, somewhat purplish beneath. Disc florets 20 to 23; corollas 5-5.6 mm long, yellowish; style branches truncate with a crown of sweeping trichomes, yellowish. Achenes cylindrical, white-villous (immature); pappus 3.9-6.2 mm long, barbellate, whitish. Chromosome number unknown. Fig. 10 .

Additional iconography.

Calvo and Funk (2020: 32, fig. 2, as photo).

Distribution and habitat.

Endemic to Ecuador ( Bolívar, Chimborazo). This species grows in exposed places and on sandy soils of the dry superparamo ecoregion, at elevations of 4100-4300 m (Fig. 9 ).

The species is known from a few collections near the Chimborazo Volcano. Its distribution area partially overlaps with those of X. humile and X. rigidum . See Calvo and Funk (2020) for further details.

Phenology.

Flowering from April to July.

Etymology.

The epithet honors the American botanist Vicki A. Funk (1947-2019), who described the genus Xenophyllum and greatly contributed to the understanding of the family Compositae .

Notes.

Xenophyllum funkianum is distinguished by its creeping rhizome-like stems 20-35 cm long, the straight linear leaves extending into a sheath-like base that bears arachnoid trichomes, the dark-burgundy sessile involucres with 13 to 14 involucral bracts, the 12 to 13 ray florets with white corollas somewhat purplish beneath, and by having white-villous achenes.

The morphologically closest species is X. rigidum . However, they can be differentiated by the leaf lamina size (5.3-7.8 × 0.8-0.9 mm in X. funkianum vs. 12.6-13.5 × 2.3-2.4 mm in X. rigidum ), involucre size (9-11 × 5-7 mm in X. funkianum vs. 11.5-12.8 × 7.2-11.3 mm in X. rigidum ), number of disc florets (20 to 23 in X. funkianum vs. 38 to 41 in X. rigidum ), and by the way of growing of the rhizome-like stems (distinctly horizontal in X. funkianum vs. rather erect in X. rigidum ). Xenophyllum funkianum is, furthermore, a smaller plant and the capitula are not enclosed among the leaves as in X. rigidum . Another similar species is X. humile ; they differ in involucre length (9-11 mm in X. funkianum vs. 4.6-9.3 mm in X. humile ), achene indumentum (white-villous in X. funkianum vs. glabrous in X. humile ), and habit (rather creeping in X. funkianum vs. forming dense mats or hummocks in X. humile ). Moreover, X. funkianum differs in having the leaf lamina barely spreading from the sheath-like base (vs. leaf lamina usually spreading at nearly 90° from the sheath-like base in X. humile ).

Additional specimens examined.

Ecuador. Bolívar: road to Salinas, 1.8 km W of Guaranda-Ambato hwy., 1°25'S, 79°0'W, 25 Jun 1989, L.J. Dorr & I. Valdespino 6474 (QCA, QCNE, US); Chimborazo: Mt. Chimborazo area, side road ends and connects to trail that leads to the Polylepis forest, 1°32'S, 78°53'W, 20 Apr 2018, V.A. Funk & J.M. Bonifacino 14061 (US); W side of the Chimborazo volcano, arenal around loma Guagua Lozán, 1°27'S, 78°54'W, 3 Jul 1999, P. Sklenář 7528 (QCA, QCNE).

Figures

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

Figure 10. Xenophyllum funkianum A habit B habit with capitula C stem apical part D detail of leaf apex E capitulum F ray floret (frontward bristles removed) G disc corolla and style branches H stamen. All details drawn from Funk & Bonifacino 14059 (US). Illustration by Alice Tangerini.