Rottboellia husainii P. Agnihotri & S. Tripathi, 2021

Tripathi, Shailja, Jaiswal, Shubham, Prasad, Dileshwar, Yadav, Rekha, Saxena, Gauri & Agnihotri, Priyanka, 2021, Rottboellia husainii (Poaceae: Andropogoneae), a new grass species from Western Himalaya, India, Phytotaxa 507 (1), pp. 98-104 : 99-102

Rottboellia husainii P. Agnihotri & S. Tripathi sp. nov. ( Fig.1–2 , Table 1)

Type:— INDIA. Jammu and Kashmir: Ramban, on the way to Nathatop, Rakh Jargoh , 33.096102N & 75.312527E, 2077 m, 17 July 2019, Shailja Tripathi, Shubham Jaiswal & Rekha Yadav 316339 (holotype LWG!, isotype LWG!) .

Diagnosis:— Differs from R. cochinchinensis by hairy leaf sheath margin (vs. glabrous), spikelets 5.5–6.5 mm long (vs. 3.5–5.0 mm long), pedicels 3.5–4.0 mm long (vs. 3.0– 3.5 mm long); glumes 5.5–6.0 mm long (vs. 4.5–5.0 mm long) and glumes bearing tuberculate spiny hairs on upper margin (vs. glabrous) and anthers 3.0– 3.5 mm long (vs. 2.0– 2.5 mm long).

Description:— Annual herbs. Roots fibrous. Culms upto 100 cm high, slender, erect, glabrous; nodes 4–5, sparsely hairy, lower nodes frequently giving rise to roots. Leaf sheaths 5–10 cm long, terete, hairy. Leaf blades 15–30 × 0.8–1.0 cm, flat, linear-lanceolate, smooth on the adaxial surface, margins serrate, base truncate, apex acuminate; collar sparsely hairy. Ligules fringe of hairs. Inflorescence a spike like raceme, 10–20 cm long, emerging from upper leaf sheath, terete, hairy, peduncles thick exserted from spathe. Pedicels and rachis joints (internodes) cylindrical, joints 5.5–6.5 mm long, minutely ciliate. Sessile spikelets bisexual, 5.5–6.5 × 0.5–1.0 mm, lanceolate-ovate, sparsely hairy, without awns, callus pilose. Lower glume 5.5–6.0 × 1.0– 1.5 mm, lanceolate, chartaceous, glabrous or slightly pubescent on the upper margins, muticous, 7–9(–13)-nerved, margins curved inwards, apex obtuse. Upper glume 5.5– 6.0 × 1.0– 1.3 mm, lanceolate, membranous, muticous, margins curved inwards, apex acute. Lower lemma 5.0–5.5 × 1.0– 1.2 mm, lanceolate, coriaceous; palea not present; anthers 3, anthers 3.2–3.5 mm long, light brown. Upper lemma 4.5–5.0 × 1.0– 1.5 mm, coriaceous, glaucous, margins curved inwards; palea membranous, delicate, hyaline; anthers 3, 3– 3.5 mm long; pistil 2.3–2.5 mm long. Pedicels fused with the joints, 3.5–4.0 mm long. Pedicellate spikelet 5.5–6.0 × 0.5–1.0 mm long, staminate, similar to the sessile spikelets in indumentum, muticous. Lower glume 5.5–6.0 × 1.0– 1.5 mm, lanceolate, chartaceous, muticous, margins curved inwards, 7–9-nerved. Upper glume 5.5–6.0 × 1.0– 1.2 mm, lanceolate, membranous, apex acute; lower floret sterile. Lower lemma 3.0– 3.5 mm long, hyaline, 1-keeled, apex acute; palea hyaline, 1.5–2.0 mm long, apex acute. Upper lemma 3.0– 3.5 mm long, hyaline, muticous; palea not present; anthers 3.0– 3.5 mm long, golden-yellow.

Flowering:—July–August

Habitat and distribution:— Rottboellia husainii is so far known only from its type locality in Ramban district of Jammu and Kashmir ( Fig. 3 ). Ramban, situated in the lap of Pir Panjal range along the river Chenab is a hilly and mountainous region with rugged topography, steep slopes, high ranges, deep valleys and gently sloping meadows. The lower fringes of this area are honey combed with human habitation under immense biotic pressure, as a result the region experiences pronounced effects of grazing and human pressure. To meet out the increasing demand of land for agriculture and settlement, encroachments have been in trend leading to habitat fragmentation. It has been observed that anthropogenic activities including urbanization and overgrazing by domestic animals influence the distribution of the new species as we could locate R. husainii in patchy areas.

Etymology:— The specific epithet is named after Dr. Tariq Husain, former scientist, CSIR- National Botanical Research Institute, Lucknow to commemorate his contribution in the field of Angiosperm Taxonomy.

Notes:— The species was found growing in association with Digitalis purpurea Linnaeus (1753: 621) and Phleum pratense Linnaeus (1753: 59) and was apparently different from other existing population. Occurrence of solitary spike like raceme, cylindrical pedicels and rachis internodes, paired and sunken spikelets, and muticous glumes, place the new species in Rottboellia . R. husainii is characterized by its hairy nodes, longer spikelets, hairy joints and longer pedicel, features that can distinguish the new species from its closely allied species R. cochinchinensis . R. husainii differs from R. goalparensis in possessing longer raceme, while it can be differentiated from R. clarkei and R. striata by having pedicels of the spikelet fused with joints (internodes) of the rachis.

Additional specimens examined: — R. cochinchinensis : INDIA. Uttarakhand: Dehradun, Mothrowala , 28 October 1958, K.M.M. Dakshini 6280 (BSD!); Ranmagar, Mohaan road, 27 September 1969, S.V. Rao 39944 (BSD!); Sahiya, 14 September 2001, M.K. Kandwal 775 (BSD!) .

Figures

FIGURE 1. Rottboellia husainii sp. nov. A. Habit. B. Culm and leaf sheath. C. Ligule. D. Nodes of the culm and leaf sheath. E–F. Pair of spikelets. G. Sessile spikelet, adaxial view. H. Sessile spikelet, abaxial view; I. Joint (internode). J. Pedicel. K. Lower glume of sessile spikelet. L. Upper glume of sessile spikelet. M. Upper lemma; N. Palea. O. Anthers.

FIGURE 2. A. Culm and leaf sheath. B. Ligule. C. Nodes of the culm. D. Inflorescence. E–F. Pair of spikelets. G. Sessile spikelet, adaxial view. H. Sessile spikelet, abaxial view. I. Pedicel. J. Lower glume of sessile spikelet. K. Upper glume of sessile spikelet. L. Joint (internode). M. Upper lemma. N. Palea. O. Anthers.

FIGURE 3. Geographic distribution of Rottboellia husainii in Ramban district, Jammu and Kashmir, India, represented by red circle.