Trichoneura peruviana Gut.Peralta & Montesinos, 2020

Gutiérrez, Harol, Castañeda, Roxana, Montesinos-Tubée, Daniel B., López, Jorge, Gonzales, Teresa, Norabuena, Edgar & Sotelo, Alejandrina, 2020, Trichoneura peruviana (Poaceae, Trichoneurinae), a new species from Peru, Phytotaxa 442 (3), pp. 232-238 : 233-235

Trichoneura peruviana Gut.Peralta & Montesinos sp. nov. ( Figs. 1–4 )

Trichoneura peruviana differs from T. lindleyana (Kunth) Ekman in having longer glumes (lower glumes 5–5.25 × 0.2–0.25 mm and upper glumes 5.5–5.7 × 0.3–0.4 mm); fertile lemmas 2.1–2.5 mm long with ciliate margins, the cilia 0.5–0.6 mm long; lemma awned from a sinus, the awn 1.4–3.5 mm long; and membranous ligules 0.5–0.6 mm long.

Type: — PERU. Moquegua: General Sánchez Cerro, Omate, Road to Omate, flat rocky slopes with cacti near, 16°46’27”S, 70°57’52”W, 1390 m, 20 Mar 2019, D. B. Montesinos & K. Chicalla 7437 (holotype MOL!, isotype HSP!).

Erect, caespitose, annuals. Culms 5–8 cm tall, erect, unbranched or weakly branched near the base. Leaves usually all basal; leaf sheaths pilose, some hyaline hairs up to 1.2–1.4 mm long; ligules 0.5 – 0.6 mm long with an eciliate membrane, truncate; blades 2 – 10 cm long, 0.4 – 0.5 mm wide, tightly involute or flat, pubescent, apex attenuate. Inflorescence composed of racemes; racemes 1 – 1.5 cm long, borne along a central axis, unilateral; central axis 1 – 2 cm long; rachis not deciduous, angular. Spikelets packed broadside to rachis and appressed, solitary; fertile spikelets oblong, pedicelled, the pedicels 0.6 – 0.7 mm long. Spikelets 4 – 5 mm long, 2−4-flowered, cuneate, laterally compressed, falling entire with the pedicel and readily disarticulating between the florets, upper florets sterile resembling the lower but underdeveloped; callus pubescent; glumes nearly equal in length, 1-veined, keeled, membranous, apex acuminate, gaping; lower glumes 5–5.25 × 0.2–0.25 mm, lanceolate; upper glumes 5.5–5.7 × 0.3–0.4 mm; fertile lemma 2.1–2.5 mm long, oblong, membranous, keeled, 3 –veined, pubescent on the lateral veins, margins ciliate, the cilia 0.5–0.6 mm long, apex dentate, 2-fid, awned between the sinus, the awn 1.4–3.5 mm long; paleas 1.4–2.5 mm long, 2-veined; stamens 3, anthers 0.2–0.3 mm long, oblong. Caryopses 1–1.3 (–1.5) × 0.1–0.2 mm, oblong.

Ecology and distribution —Xeric areas in the transitional coastal Andean valleys at 1390 m in southern Peru.

Etymology —The specific epithet indicates the country of origin.

Discussion — Trichoneura peruviana is morphologically similar to T. lindleyana ( Kunth 1833: 525) Ekman (1912: 9) from the Galapagos Islands ( Ecuador), in having basally inserted leaves and non-branched culms, hairy leaf sheaths with hairs 1–1.5 mm long. Trichoneura peruviana differs from T. lindleyana in having, smaller lemmas (2.1–2.5 mm long vs. 2−4 mm) and longer glumes (lower glume 5–5.25 mm long vs. 3.5–4 mm long; upper glumes 5.5–5.7 mm long vs. 4–5 mm long), pilose leaf-sheaths vs. glabrous, principal lemma awns 1.4–3.5 mm long vs. 0.5–1 mm long, and shorter ligules 0.5–0.6 mm long vs. 1.3 mm long ( Clayton et al. 2016).

Conservation status —Considering the IUCN (2017) criteria, the assigned conservation status is Vulnerable (VU) under criteria D2, with an area of occupancy (AOO) <20 km 2 and number of localities ≤ 5. The new species is often found with low populations, usually less than 5 individuals /m 2.

Figures

FIGURE 1. Trichoneura peruviana (photograph of the D.B. Montesinos & K. Chicalla 7437 holotype MOL!).

FIGURE 2. Raceme of Trichoneura peruviana (photograph of the D.B. Montesinos & K. Chicalla 7437 holotype MOL!).

FIGURE 3. Spikelet of Trichoneura peruviana (photograph of the D.B. Montesinos & K. Chicalla 7437 holotype MOL!).

FIGURE 4. Type locality of Trichoneura peruviana in Moquegua, Peru.