Agrostis barikii P. Agnihotri & D. Prasad, 2021

Prasad, Dileshwar, Yadav, Rekha, Jaiswal, Shubham, Tripathi, Shailja & Agnihotri, Priyanka, 2021, Agrostis barikii (Poaceae: Agrostidinae), a new grass species from Western Himalaya, India, Phytotaxa 494 (1), pp. 145-150 : 146-148

Agrostis barikii P. Agnihotri & D. Prasad , sp. nov. ( Figs. 1–3 )

Diagnosis:—Differs from Agrostis griffithiana by its ligule short-ciliate (vs. non-ciliate), lower glume 2.3–3.2 mm long (vs. 3.2–4.2 mm long), absence of mucro at lemma tip (vs. mucro present, 0.2−0.4 mm long), awn 1.8–3.6 mm long (vs. 4.8–5.6 mm long), and anthers 0.5–0.7 mm long (vs. 0.8–0.9 mm long).

Type:— INDIA. Uttarakhand, Chamoli, Ghangharia, Nanda Devi Biosphere Reserve , Valley of Flowers National Park , 30.708117°N, 79.596247°E, 3175 m, 23 August 2019, P . Agnihotri, D. Prasad, R . Yadav & S. Jaiswal 326659 (holotype LWG, Isotype BSD) .

Perennial, caespitose, roots fibrous, densely tufted grass, 10–35 cm tall. Culms 8–29 cm long, geniculately ascending, 1–2 mm in diameter, terete, glabrous, 2–3-noded below the panicles. Nodes glabrous, constricted. Distal leaf blades 25–210 × 0.8–2.5 mm, convolute, adaxial surface scaberulous, abaxial surface glabrous; basal blades 65–90 × 1.3–1.4 mm, setaceous, glabrous. Ligules 1.3–3.5 mm long, abaxial surface scabrous, apex truncate, short-ciliate. Panicles 3.5–10.5 × 0.4–1.1 cm, lanceolate, contracted, lower branches in whorls of 2–4, 2.5–7.5 mm long. Spikelets 2.3–3.2 × 0.8–1.5 mm (excluding awn), 1-flowered, bisexual, laterally compressed, rachilla disarticulating above the glumes; glumes equal or subequal, glabrous, lower glume 2.3–3.2 × 0.8–1 mm, 1-nerved, 1-keeled, elliptic to lanceolate, apex acute, keel ciliate on the upper half; upper glume 2.1–3.2 × 0.7–1.1 mm, 1-nerved, 1-keeled, elliptic, apex acute, keel ciliate; lemma 1.5–2.2 mm long, 5-nerved, membranous, hairy on the dorsal surface, except at the apex, 2/3 the length of the lower glume, margin hyaline, entire, apex truncate, entire; rachilla extensions absent; palea 1.2–1.6 mm long, 2-nerved, hyaline, glabrous, 2/3 the length of the lemma; awn 1.8–3.6 mm long, inserted 0.4–0.6 mm long above the base of the lemma, geniculate, extending above the glumes, column twisted, 1–1.6 mm long; callus hairs 0.4–0.7 mm long, in two small tufts on the ventral side; stamens 3; anthers 0.5–0.7 mm long; caryopsis 1.3–1.6 × 0.3–0.5 mm, lanceolate, color golden-brown.

Flowering and fruiting:—Fertile material of Agrostis barikii was gathered from August to October.

Habitat and distribution:— Agrostis barikii is known from the Indian Western Himalayan region. The new species was found in two localities of Uttarakhand, the Kedarnath Wildlife Sanctuary and the Valley of Flowers National Park, and one locality in the Rohtang Pass of Himachal Pradesh ( Fig. 3 ). Based on these records, we believe, it is distributed from Garhwal Himalaya to Pir Panjal range of Western Himalaya. It grows between alpine and subalpine zones at an elevation of 2650–3600 m a.s.l., in open slopes of alpine grasslands, rock boulders of landslide areas, and rocky surface of alpine meadows.

Taxonomic affinity:—The caespitose grass A. barikii has lemma with pilose dorsal surface, a typical character of the A. pilosula group, and thus we here assign it to this morphological group. It is most similar to A. griffithiana due to its hairy lemma (except at the apex), similar ratio of palea length to lemma length, and well developed awns, but they differ by a combination of features, including ligule shape, lower glume length, lemma apex, and size of anthers ( Table 1) ( Fig. 1–2 ). Agrostis barikii and A. pilosula have well developed geniculate awns, and glumes and lemma of similar size, but differ by the ratio of palea length to lemma length (0.18−0.55 mm vs. 0.72–0.80 mm) ( Fig. 1G , Fig. 2E ). Agrostis munroana and A. pendryi are characterized by weak, straight, and short awns which do not exsert from the glumes, whereas A. barikii has well developed awns which are geniculate and conspicuously exserted ( Fig. 1B–C ). Agrostis barikii also differs from A. pendryi by the ratio of palea length to lemma length (0.72–0.80 mm vs. 0.35−0.58 mm) ( Fig. 1G , Fig. 2E ). In A. pendryi , the dorsal surface of the lemma is hairy, except near the base ( Paszko 2014), whereas in A. griffithiana and A. barikii the lemma is hairy, except at the apex ( Fig. 1F–G , Fig. 2E ).

Etymology:—The specific epithet of the new species is given in honor of Professor S.K. Barik, in recognition of his remarkable contributions in the field of Taxonomy and Ecology of Angiosperms.

Additional specimens examined (paratypes):— INDIA. Uttarakhand, Chamoli, Ghanghria, Nanda Devi Biosphere Reserve , Valley of Flowers National Park , 30.729139°N, 79.596606°E, 3567 m, 23 August 2019, P . Agnihotri, D. Prasad, R . Yadav, S . Jaiswal 326627 ( LWG!); Rudraprayag, Kedarnath Wildlife Sanctuary , Gaurikund to Kedarnath trekking way, Gaurikund , 30.692313°N, 79.051968°E, 2711 m, 13 October 2019, R . Yadav & D. Husain 328459 ( LWG!); same locality, 13 October 2019, R . Yadav & D. Husain 328460 ( LWG!) . Himachal Pradesh, Kullu, Manali, Rohtang pass, Marhi , 32.341507°N, 77.216715°E, 3260 m, 5 August 2019, D. Prasad & R . Yadav 316297 ( LWG!) .

Figures

FIGURE 1. Agrostis barikii. A. Ligule. B–C. Spikelets, lateral view. D–E. Spikelet with floret separated from the glumes. F. Floret in dorsal view showing the well-developed awn, G. Floret in lateral view showing the awn, the lemma glabrous at the apex, and the palea. H. Palea, ventral view. I. Anthers. J–K. Caryopsis, dorsal (left) and ventral (right) views. [Photographs from P. Agnihotri et al. 326659 (LWG)].

FIGURE 2. Agrostis barikii; A. Base of the plant showing the habit caespitose. B. Ligule. C. Panicle. D. Spikelet with floret separated from the glumes, lateral view. E. Floret, lateral view. F. Palea, ventral view. G. Anthers. H. Caryopsis in dorsal (left) and ventral (right) views. [Illustration from P. Agnihotri et al. 326659 (LWG); drawn by Mr.Akash Verma].

FIGURE 3. Geographic distribution of Agrostis barikii. (HP: Himachal Pradesh; UK: Uttarakhand).