Bromus husainii P. Agnihotri & R. Yadav, 2021

Yadav, Rekha, Prasad, Dileshwar, Tripathi, Shailja, Jaiswal, Shubham & Agnihotri, Priyanka, 2021, Bromus husainii (Poaceae: Bromeae), a new species from Valley of Flowers National Park, Uttarakhand, India, Phytotaxa 516 (1), pp. 73-82 : 74-78

Bromus husainii P. Agnihotri & R. Yadav sp. nov. ( Figures 1, 2 , 3 & 4 )

Type:— INDIA. Uttarakhand: Chamoli district, Valley of Flowers National Park , 30.729139º N, 79.596606º E, 3567 m, 23August 2019, R . Yadav, D. Prasad, S . Jaiswal & P. Agnihotri 326619 (holotype: LWG!, isotype: LWG!) .

Diagnosis: —The new species differs from B. confinis Nees ex Steud. (1854: 320) in having heteromorphic spikelets (normal and robust spikelets) (vs. single type spikelets); a band of hairs present on its collar (vs. absent); spikelets 3.3–4.3 cm long (vs. 1.5–2.5 cm long); upper glume 13–16 mm long (vs. ca. 9 mm long); lemma 17.3–20.5 mm long (vs. 10–15 mm long); awn 6–10 mm long (vs. 2.5–6 mm long); palea shorter than lemma (vs. as long as lemma); anthers 3.4–3.6 mm long (vs. 3.5– 4 mm long) and robust spikelets (vs. absent).

Description:— Perennial, strongly rhizomatous, tufted. Culms 0.7–1.5 m tall, 2.0–5.0 mm wide at base, erect or geniculately ascending, solitary, rigid, terete, glabrous or pubescent below inflorescences; nodes 4–6, densely or sparsely pubescent, hairs soft or stiff, up to 1.5 mm long. Old basal leaf sheath persistent, conferring the culm base, extravaginal innovation leaves with short blades, same as cauline leaves; cauline leaf sheaths ribbed or striped; abaxial surface pubescent to sparsely pilose, hairs sometimes restricted to sheath margins; hairs soft upto 1.5mm long; auricles absent; ligules membranous, glabrous, 2.5–4 mm long, margin entire with erose apex; leaf blades 30–45 cm × 8–10 mm, flat, adaxial surface sparsely pubescent to pilose, hairs up to 1.5 mm long, abaxial surface veins scabrous but surface sparsely pubescent; margins entire or serrulate, at collar a band of hairs present; apex acuminate. Panicle 15–40 cm long, lax, nodding, branches ascending to patulous, shorter or longer than spikelet, 1–7 spikelets per branch; pedicels scabrous with minute antrorse teeth; rachis glabrous or scabrous. Spikelets heteromorphic, normal and robust. Robust spikelets fewer in number than normal spikelets, present at terminal and sub-terminal axis of rachis, 1–3 per branch. Normal spikelet 33.2–43.8 × 3.0– 6.2mm, 6–8 fertile florets with 1–3 rudimentary florets, imbricate in young stage, at maturity, florets separate, oblong-lanceolate, slightly laterally compressed; rachilla internode 2.9–3.3mm long, scabrous hairs and laterally visible at maturity; lower glumes 8.5–10.9 × 1.3–1.7mm, 1-nerved, lanceolate, keeled, margins hyaline, pubescent to scabrous hairs, sometimes scabrous hairs restricted to apex along with veins and upper half margins, apices attenuate to acuminate; upper glumes 13–16 × 1.5–2mm, 3-nerved, narrowly obovate-lanceolate, strongly keeled; apex acute to acuminate, scabrous or pubescent hairs at apex along with veins and upper half margins, surface glabrous or sometimes scabrous-pubescent; lemma 7-nerved, oblong-lanceolate, slightly rounded over the backs to keeled, pubescent or minutely scabrous hairs present on nerves and base of the lemma margin and sometimes also at surface and margin, intermediate nerve inconspicuous, first 17.3–20.5 × 2.2–3.3mm (without awn); apices minutely bifid; awns scabrous, slender, inserted 0.1–0.5 mm below the lemma apex, 6–10mm long, slightly curved or straight; palea linear-lanceolate, 10.5–12.9 × 1.0– 1.5mm, 2-keeled, keels ciliated, cilia 0.7–0.8mm long, apices entire or bifid; lodicules 2, 0.7–0.8mm long lanceolate-oblong, glabrous; anthers 3, 3.4–3.6mm long; fruit caryopsis. Robust spikelet 40–45 × 4.8–6.2mm, 2–3 fertile florets with 4–6 sterile florets, oblong-lanceolate, subterete or moderately laterally compressed; rachilla reduced or sometimes absent, lower glumes 11.5–16.8 × 1.5–2.2mm, 1-nerved, strongly keeled, lanceolate, pubescent hairs on nerves with glabrous surface, apices awn like or acuminate; upper glumes 12.1–16.8 × 2.0– 2.8mm, 3-nerved, pubescent hairs at nerves with glabrous surface; apices awn like or acuminate. Fertile floret: Lemma first 14.2–18.5 × 3.8–5.2 mm (without awn), 7-nerved, surface glabrous or minutely pubescent, nerves and upper half lemma hairy, oblong-lanceolate, rounded over the back, intermediate nerve inconspicuous, apices minutely bifid, awn scabrous, terminal or subterminal, 5.0–11.3 × 0.7–0.9mm or sometimes absent, straight or slightly curved; paleal inear-lanceolate, conspicuously shorter than lemma, 3.8–5.3 × 0.8–1.0mm, 2-keeled; keels ciliate; cilia 0.07–0.08mm long, apices entire or bifid; lodicules absent; anthers 3, 1.8–2.6mm long; fruit caryopsis. Sterile floret: Lemma 20–30- nerved, 25.5–45mm long, glabrous, awned or without awn; awn 2–6mm long; apices entire, sixth or seventh sometimes third or fourth lemma encircles remaining inner lemmas, encircling lemma length same as spikelet; palea, lodicules, anthers and caryopsis absent.

Etymology: —The specific epithet is named to honour Dr. Tariq Husain, former Scientist, CSIR- National

Botanical Research Institute, Lucknow for his remarkable contributions in the field of Angiosperm systematics.

Flowering & fruiting period: —Plants have been collected in flowering in the month of August, at the same time some plants were in fruiting condition, therefore, the flowering and fruiting period may be considered from July to September.

Distribution and ecology: — Bromus husainii is currently known only from its type locality i.e. Valley of Flowers National Park occurring at an altitude of about 3567 m asl. ( Figure 6 ). The valley is located within transition zone between Zanskar and Great Himalaya ranging to the north and south, respectively. The climate in the valley is cool, foggy and humid that supports a spectacular diversity of plants. Competitive superiority of the prominent tall herbaceous plants including Ligusticopsis wallichiana ( De Candolle 1830: 158) Pimenov & Kljuykov (2001: 122) , Campanula latifolia Linneaus (1753: 165) , Morina longifolia Wallich ex De Candolle (1830:644) , Codonopsis rotundifolia Bentham (1839:254) , Himalaiella auriculata (De Candolle 1838: 541) Raab-Straube (2003: 390) , etc. could be the reason of speciation of existing species of Bromus Linnaeus (1753: 77) i.e. B. arvensis Linnaeus (1753: 77) and B. ramosus Hudson (1762: 40) from this region ( Bisht et al. 2018). The new species grows in open grasslands and in crevices of rocks and boulders at elevations ranging from 3400–3600 m asl.( Figure 5 .).

Notes: —The new species is placed in Bromus due to presence of fused leaf sheath margin, sub-apically inserted awns and hairy appendages on apices of the ovary. B. husainii is recognized by its heteromorphic spikelets (normal and robust spikelets), a feature that is not found in any other species of Bromus . Here, we have considered usual spikelets of Bromus as Normal spikelets, whereas vigorous spikelets as Robust spikelets, which are present at terminal and subterminal axis of rachis in inflorescence, consisting of densely arranged florets, rachilla often reduced or absent. The specimens of B. husainii are morphologically similar to B. confinis in having perennial habit, purple-tinged spikelets, pubescent or scabrous glumes, and straight awn but differs in circumscriptions of habit, inflorescence, collar, and spikelets ( Table 1.). The new species also shows similarities with B. ramosus by its panicle inflorescence, 1-nerved lower glume, 7-nerved lemma slightly rounded on back and awn smaller than lemma but can be easily distinguished by lower glume (8.5–10.9 mm vs. 6.0–8.0 mm), upper glume (3-nerved and 13.0–16.0 mm vs. 5-nerved and 6.0–12.0 mm), and lemma (17.3–20.5 mm vs. 8.0–12.0 mm).

Additional specimens examined:— Bromus husainii sp. nov. (paratype): INDIA. Uttarakhand, Chamoli district, Valley of Flowers National Park , 30.729139º N, 79.596606º E, 3567 m, 23 August 2019, R . Yadav, D. Prasad , S . Jaiswal & P . Agnihotri, 326698, 326698 ( LWG!) .

Figures

FIGURE 2. Bromus husainii. A. Inflorescence. B. Robust spikelet. C. Lower glume. D. Upper glume. E–K. Lemma. L. Palea. M.Anthers. N. Gynoecium.

FIGURE 3. Bromus husainii.A. Normal Spikelet.B. Lower glume. C. Upper glume.D. Lower Lemma.E.Palea. F.Anther.G. Gynoecium. H. Lodicules.

FIGURE 4. Bromus husainii. A. Nodes. B. Collar. C. Ligule.

FIGURE 5. Bromus husainii growing in its natural habitat.

FIGURE 6. Geographic distribution of Bromus husainii in Valley of Flowers National Park, Uttarakhand, India.