Tripogon nicorae var. aristulata Gut. Peralta & P.M. Peterson, 2021

Gutiérrez, Harol, Castañeda, Roxana, Gonzales, Teresa, Mendez, Alejandrina Sotelo- & Peterson, Paul M., 2021, Tripogon nicorae var. aristulata (Poaceae), a new variety from Peru, Phytotaxa 523 (1), pp. 110-115 : 112-114

Tripogon nicorae var. aristulata Gut. Peralta & P.M. Peterson , var. nov. ( Figs. 1−3 ).

Type: — PERU. Huancavelica: Huaytara, San Isidro, rocky slopes with moderate to high slope, with seasonal vegetation, share habitat with populations of Corryocactus brevistylus (K. Schum. ex Vaupel 1913: 17) Britton & Rose (1920: 66) and Colletia spinosissima Gmelin (1791: 408) , 13°59’50.28”S, 75°15’24.06”W, 3323 m, 5 April 2018, H. Gutiérrez 169 (holotype MOL!, isotype MOL!).

Diagnosis: — Tripogon nicorae var. aristulata differs from T. nicorae var. nicorae in having narrow paleas 0.4−0.5 mm wide that are apically bilobed with two excurrent veins forming mucros 0.3–0.5 mm long.

Caespitose perennials with fibrous remains of old sheaths. Culms (2.2–) 3–5 cm tall. Sheaths striate, glabrous. Ligules 0.5–0.8 mm long, membranous, densely pilose at margins, the hairs up to 0.5 mm long. Leaf blades 15–40 × 0.3–0.5 mm, filiform, conduplicate, abaxially glabrous, with white and twisted long hairs on adaxial surface and two lateral tufts of long hairs near the ligule, margins scaberulous. Terminal raceme 0.8–2.4 cm long, straight, exserted, dark olivaceous to purplish. Rachis 0.5–0.6 mm wide, margins scaberulous. Spikelets 4–8 × 1.2–1.5 mm, 4–5-flowered, subsessile, alternate on the rachis, the distal ones crowded and the basal ones distant from each other. Glumes 1-veined, lanceolate, glabrous. Lower glume 2–2.5 mm long, apex mucronate, keels scabrous. Upper glume 2.6–3 mm long, apex obtuse. Florets imbricate. Lemmas 2.3–2.5 × 0.6–0.7 mm (not including awns), ovate, broadened at the middle third and narrow towards the apex, 3-veined, glabrous, apex bilobed, midvein prolonged in a straight awn, the awn 1.2–2.9 mm long, lateral veins excurrent and mucronate, the mucros 0.4–0.6 mm long; callus pilose, the hairs 0.5–1 mm long; rachilla internodes 0.6–0.8 mm long, glabrous, scar joint narrowly elliptic. Paleas 2 – 2.5 × 0.4 – 0.5 mm, apex bilobed with two excurrent veins forming mucros 0.3 – 0.5 mm long. Lodicules 2, ca. 0.3 mm long, apex truncate. Stamens 3, anthers 0.4–0.5 mm long, purplish. Stigmas 2, plumose, purplish. Caryopsis 1–1.5 × 0.2–0.3 mm, subtriangular in transverse section, without ventral furrows, endosperm dry, hilum ellipsoid, embryo 1/3 the length of the caryopsis.

Ecology and distribution: — This variety has been collected at high elevations in the mountains of Peru in the Department of Huancavelica and Moquegua ( Fig. 3 ), on moderate to high rocky slopes, at 2472–3600 m, with seasonal vegetation .

Etymology: —The epithet aristulata refers to the presence of two mucronate excurrent veins of the palea ( Fig. 1F ).

Taxonomical notes: — Tripogon nicorae var. aristulata can be separated from T. nicorae var. nicorae in having apically bilobed paleas with two excurrent veins that form mucros 0.3–0.5 mm long ( Fig. 1F ; vs. apex 2–toothed in T. nicorae var. nicorae ), lemmas with lateral excurrent veins with mucros 0.4–0.6 mm long ( Fig. 1D–E ; vs. 0.1–0.4 mm long), and keels of the lower glume scabrous (vs. keels smooth). The typical variety of this species occurs in Argentina, Bolivia, Chile, Ecuador, and Peru ( Rúgolo & Vega 2004), whereas the new variety is only known from Peru ( Fig. 3 ).

Additional specimens examined: — PERU. Moquegua: Mariscal Nieto, S.C. Calacoa, road to Sijuaya , rocky slope, xerophytic scrub, 16°40’16”S, 70°44’50”W, 2472 m, 19 March 2019, D. Montesinos 7418 (MOL!) .

Figures

FIGURE 1. Tripogon nicorae var. aristulata var. nov. A. Habit; B. Spikelet; C. Glumes; D. Lemma, lateral view; E. Lemma, adaxial surface; F. Palea; G. Caryopsis, hilum view. [from H. Gutiérrez 169 (MOL)].

FIGURE 2. Tripogon nicorae var. aristulata in its natural habitat in Department Huancavelica, Peru. Photo by H. Gutiérrez (5 April 2018).

FIGURE 3. Geographic distribution of Tripogon nicorae var. aristulata and T. nicorae var. nicorae.