Werneria microphylla H. Beltrán & S. Leiva, 2018

Beltran, Hamilton & Leiva, Segundo, 2018, Werneria microphylla (Asteraceae, Senecioneae), a new species from the Andean marshes of Peru, Phytotaxa 372 (4), pp. 296-300 : 297

Werneria microphylla H. Beltrán & S. Leiva , sp. nov. ( Figs. 1A–D , 2 )

Type: — PERU. Lima: prov. Huarochiri, distr. Chicla, Abra Anticona , 11º35 ′ 34 ″ S, 76º11 ′ 38 ″ W, 4877 m, 29 April 2017, H. Beltrán, S. Castillo & M. Arakaki 7970 (holotype: USM 253391 ; isotypes: HAO, HUSA, HUT) .

Small rhizomatous herb forming lax patches. Rhizomes slightly thickened and sparsely branched, flowering branches ca. 1.5 cm long, with scattered purple trichomes, sometimes purplish. Leaves simple, alternate, slightly carnose, 3.5– 6(8) mm long (including sheathing base and lamina); lamina glabrous, narrowly elliptical to widely oblong, 1.8– 4.5 mm, slightly narrowed towards the base, apex mucronate (mucro ca. 0.4–0.9 mm), sheathing base 0.5–3.5 mm, proximally ca. 1.5–5 mm wide (wider than the lamina), distally ca. 0.5–0.9 mm wide, slightly asymmetrical, 3-veined, membranaceous, margin with short trichomes <0.5 mm; leaves on the apex of the branches somewhat different from stem leaves, with lamina oblong-lanceolate, 3.5 × 1.2 mm, 1-veined, somewhat lanuginose adaxially, apex attenuate into a mucro ca. 0.9 mm. Capitulum radiate, solitary, with a short peduncle, peduncles 1.5–2 mm long. Involucre widely cylindrical, 5–6 x 4–5 mm, Phyllaries 8–13, 3.5–4.0 × 1.5 mm, oblong, fused for ca. 1/3 of their length, 1-veined, acute to obtuse at the apex, scarious on the margins, dorsally purplish. Ray florets 8(–10), 5–6 mm long, female, with apex 3- lobed; ligule 1.5 × 0.8–0.9 mm, tube 1.5–2 mm long, ovary 1 mm long, glabrous, pappus 2–3-seriate, bristles scabrid, white. Disc florets 12–23, 3.4–4 mm long, bisexual, 5-lobed, basally abruptly narrowed, lobes 0.7 mm long, purplish and covered with tiny trichomes and papillae abaxially, pale yellow. Anthers with thecae linear-lanceolate, 1–1.3 × 0.2–0.3 mm, connective appendage lanceolate 0.2–0.3 mm long. Style branches truncate, 0.5 mm long, with a crown of sweeping trichomes, purple. Achenes not seen.

Distribution and habitat: —So far the new species is only known from Peru, collected in the departments of Ancash, Huancavelica, Lima, and Puno. It grows on Andean marshlands, known as “bofedales” in Spanish, a vegetation typically found at ca. 4000 m in the puna ecosystem, characterized by the presence of species such as Azorella multifida , Calamagrostis ovata , Distichia muscoides , Hypsela reniformis , and Plantago tubulosa .

Phenology: — Werneria microphylla apparently flowers throughout the year, as many herbs from the same habitat, probably with a peak after the rainfalls occurring in March–May.

Etymology: —The specific epithet refers to the small size of the leaves.

Additional specimens examined (paratypes):— PERU. Ancash: prov. San Marcos, distr. Colla Chica , 09º40 ′ 23 ″ S, 77º03 ′ 24 ″ W, 4300 m, 4 May 2008, H. Beltrán 6475 ( USM 225364 ) ; Lima: prov. Yauyos, distr. Laraos, Malpaso , 12 May 2001, H. Beltrán 4202 ( USM 202336 ) ; Huancavelica: prov. Huancavelica, distr. Huachocolpa , alrededor de Mina Caudalosa , 23 Mar 2015, P. Gonzales 3515 ( USM 289468 ) ; Puno: prov. Melgar, Chuquisani , 4255 m, 16 Feb 2006, J. Roque 4897 ( USM 228250 ) .

Discussion: —The new entity is unique among the species of Werneria in having small leaves with lamina up to 4.5 mm long, apex mucronate, mucro 0.4–0.8 mm long, and sheathing base asymmetrical. The number of ray florets (8) is rather constant, rarely up to 10 florets are found. Additionally, unlike most of its congeners, it is a species that grows in high Andean marshes. According to the specimens available, this species has been scarcely collected, probably because of its tiny size.

The new species here described is similar to two other dwarf Werneria species also native to Andean marshes, the widespread W. pygmaea Gillies ex Hooker & Arnott (1841: 348) , occurring from Colombia to Argentina and Chile, and W. spathulata Weddell (1855: 85) , distributed from Central Peru to Argentina. However, W. pygmaea ( Fig. 1E ) and W. spathulata ( Fig. 1F ) are larger regarding the leaf size. Werneria pygmaea has the lamina linear-lanceolate and 3 cm long, the adaxial side with long-ciliate trichomes or with axillar tufts of trichomes, and apex obtuse. Werneria spathulata has the lamina spatulate and up to 2.5 cm long with the sheath very long and ventrally glabrous. The distinctive character of W. microphylla is the presence of a mucro in the leaf apex, with lamina narrow-elliptic to broadly oblong up to 0.45 cm long, asymmetrical sheath wider than the lamina.

Figures

FIGURE 1. A–D. Werneria microphylla. A. Habit. B. Capitulum. C–D Leaves. E. Werneria pygmaea. Leaf. F. Werneria spathulata. Leaf.

FIGURE 2. A–J. Werneria microphylla. A. Capitulum. B. Ray floret. C. Disk floret. D. Inmature achene. E. Anther. F. Style. G–J. Leaves.