Tripogon trifidus Munro ex Stapf, Bull. Misc. Inform. Kew 1892

K., Thoiba, Abstract, A. K. Pradeep & Roem., Tripogon, 2020, A revision of Tripogon (Poaceae: Chloridoideae) in India, Rheedea 30 (3), pp. 325-378 : 366-368

Tripogon trifidus Munro ex Stapf, Bull. Misc. Inform. Kew 1892 (64): 85. 1892; Hook.f., Fl. Brit. India 7(22): 286. 1896; Bor, Grass. Burma Ceylon India & Pakistan 524. 1960; S.Moulik, Grass. Bam. India 2: 623. 1997; Potdar, Salunkhe & S.R.Yadav, Grass. Maharashtra: 564. 2012. Lectotype (designated by Noltie, 1999): INDIA , Meghalaya, Khasia hills, alt. 4–5500 ft., s.d., Griffith 6634 (K [K000245010 digital image!]).

Tripogon tirumalae Chorghe, Rasingam, Prasanna & Sankara Rao, Phytotaxa 131(1): 17. 2013 , syn. nov. Type: INDIA , Andhra Pradesh, Tirumala hills, near Kumaradara Pusupudara Dam , N 13 ̊43.509', E 79 ̊19.345', 990 m, 04.09.2012, L . Rasingam, M. S . Rao & Alok Chorghe 2914 (holo CAL [ CAL0000025198 !]; iso BSID!) .

Tripogon umae-ganeshii B.R.P.Rao & M.Anil Kumar, Indian J. Forest. 41(1): 97. 2018, as “ uma-ganeshii ”, syn. nov. Type: INDIA , Andhra Pradesh, Horsely hills, N 13 ̊38'44.0'’, E 78 ̊24'50.1'’, 1195 m,

19.09.2016, B . Ravi Prasad Rao & Midigesi Anilkumar 51980 (holo SKU digital image!; iso BSID) .

Tripogon nallamalayanus Rasingam & J.Swamy, Phytotaxa 351(4): 296. 2018 , syn. nov. Type: INDIA, Telangana, Mahbubnagar district, Umamaheshwaram, N 16 ̊36'989'', E 78 ̊73'168'', 700 m, 22.10.2016, L. Rasingam & J. Swamy 7396 (holo CAL!; iso BSID [ BSID0016571 digital image!]). FiGS. 40 & 41

Caespitose perennials. Culms 20–95 cm high; nodes glabrous. Leaf sheaths 4–12 cm long, linear, glabrous, persistent, inrolled to the culm; ligules a densely ciliate membrane, cilia 0.3–1.2 mm long, often glabrous when dry; leaf blades 10–70 × 0.1– 0.2 cm, linear-lanceolate, filiform, involute, ribbed, sparsely hairy adaxially and glabrous abaxially, margins scabrid, acuminate to attenuate at apex. Racemes 5–35 cm long, solitary, spike like, spikelets loosely or tightly arranged in rachis; rachis angular; peduncle 7–25 cm long, glabrous. Spikelets 4–16 × 0.7–2 mm, elliptic, greenish to yellow, 5–20- flowered, disarticulation of florets from above glumes and in between florets; callus bearded; rachilla 0.3–0.5 mm long, not persistent; lower glumes 2–4 × 0.5–0.7 mm, lanceolate, asymmetrical, 1-nerved, 1-keeled, acuminate, attenuate or mucronulate at apex, unlobed at maturity; upper glumes 3–5 × 1–1.2 mm, lanceolate, 1-nerved, 1- keeled, apex 2-toothed at maturity, mucronate or minutely awned at sinus; lemmas 3–4.5 × 1–1.3 mm (excluding awn), elliptic-lanceolate, 2-lobed, 3- nerved, 3-awned or not, median awns 2.8–4.5 mm long, scabrid, slightly geniculate, flexuous or recurved, lateral lobes acute to acuminate or sometimes lateral veins extended to lateral awns, awns 0.2–0.5 mm long; paleas 2–2.6 × 0.5–0.6 mm, obovate-elliptic, narrowly winged, hyaline, 2- keeled, 2-nerved, ciliate along the margins, apex 2-lobed or bidentate; lodicules 2, 0.1–0.2 mm long, 2-toothed at apex; stamens 3, anthers 0.5–0.7 mm long, oblong, filaments 0.3–0.4 mm long, slender; ovary 0.2–0.3 × c. 0.25 mm, obovate, styles 0.3–0.4 mm long, slender, hyaline, stigma c. 0.5 mm long, plumose, creamy white. Caryopses 1.6–2.5 × 0.25– 0.3 mm, elliptic-lanceolate, dark brown.

Flowering & fruiting: Flowering and fruiting from September to October.

Habitat: Rare on rocky hill slopes, it grows on rocks at elevations between 800 to 2500 m, in association with Chamaecrista mimosoides (L.) Greene. ( Fabaceae ), Apluda mutica , Digitaria longiflora (Retz.) Pers. , Eragrostiella bifaria , E. brachyphylla (Stapf) Bor , Heteropogon contortus (L.) Roem. & Schult., Ischaemum sp. , Lophopogon tridentatus Hack. , Tripogon bromoides and T. wightii (all Poaceae ).

Distribution: India , Nepal, Bhutan, Myanmar, China, Thailand and Vietnam.

Specimens examined: INDIA , Andhra Pradesh, Chittor district, Arai, Nagalakona, 23.02.2017, K. Thoiba & Mohammed Yoonus 146781; Penchalakona hills, 08.09.2016, Mohammed Yoonus, Nikhil Krishna & K. Thoiba 146782; Talakona watch house, 09.12.2017, Soumya, Geethika & K. Thoiba 146791 (CAL); Penchalakona hills, s.d., s.coll. 146782 (CALI); Nellore district, Rapur Ghat, 09.10.2016, B.R.P. Rao & M. Anil Kumar 52148 (SUK). Maharashtra, Dhule district, Tarad, near Shirpur, 17.09.2015, K.V.C. Gosavi & K. Thoiba 146784 (CALI). Meghalaya, East Khasi hills district, Cherrapunjee, 07.1878, G. Gallatly 476; K hills, 09.1856, s.coll. s.n.; K & J hills, 22.12.1959, G. Panigrahi 19282; Ibid., 24.09.1886, C.B. Clarke 45089; Khasia, 25.09.1886, C.B. Clarke 45671A; Ibid., Kullong, 23.08.1885, C.B. Clarke 40028; Ibid., 29.08.1886, C.B. Clarke 45092; Mawphlang, 11.09.1886, C.B. Clarke 44707A; Shillong, Bishop Falls, 26.09.1885, C.B. Clarke 40543; s.loc., 08.1919, P.W. Meekinnon s.n. (CAL).

Notes: Tripogon trifidus is extremely variable. Specimens from northeast and southern India often look different. The height of the plant varies from 20–95 cm, the ligules are very short and ciliate at maturity, but at the flowering stage, long pilose hairs may be present at the throat, which fall down when reaching maturity. Both awned and unawned types of lemmas (from young and mature racemes) are seen in a single collection.

Tripogon tirumalae was described by Chorghe et al. (2013) based on collections from Tirumala hills in Andhra Pradesh. The authors distinguished T. tirumalae from T. trifidus by its height (60–75 cm), glabrous leaf sheaths near the tip, unawned lemma lobes, median awns being 1.5 times longer than the lemma. An examination of T. trifidus specimens available in Indian herbaria, along with live collections from Tirumala and adjacent hill ranges in Chittoor district of Andhra Pradesh revealed that T. trifidus is a highly variable taxon. An examination of the type specimens (L. Rasingam, M.S. Rao & Alok Chorghe 2914) available at CAL and BSID and a number of collections from the type locality also revealed the characters used to distinguish T. tirumalae from T. trifidus are rather variable and cannot be relied upon. Hooker (1896) had also observed that the lobes of the lemma are “awned or irregularly toothed” in T. trifidus . The length of the median awn of the lemma also ranges from 2.8 mm to 4.5 mm. Examination of the types of both the taxa also support the merging of Tripogon tirumalae under T. trifidus . The other two recently described species T. nallamalayanus Rasingam & J.Swamy and T. umae-ganeshii B.R.P.Rao & M.Anil Kumar also belong to T. trifidus . Rasingam and Swamy (2018) distinguished T. nallamalayanus from T. trifidus by its glabrous leaf sheaths, longer spikelets and geniculate awn on the lemma. These characters are also variable and cannot be relied upon for their segregation. The leaf sheath of T. trifidus is always pubescent when young, later the hairs fall off and the sheath appears glabrous. The length of the spikelets varies from 4 to 16 mm, and the awn may be straight, wavy or shortly geniculate in this species. According to Rao and Anil Kumar (2018) Tripogon umae-ganeshii differs from T. trifidus in having longer (30–70 cm) leaf blades, glabrous leaf sheath, more florets (13–20) in the spikelets. All these characters are also shared by T. trifidus , and hence the names, T. nallamalayanus and T. umae-ganeshii are reduced to synonymy of T. trifidus .

Figures

FiG. 40. Tripogon trifidus Munro ex Hook.f.: a. Habit; b. Spikelet; c.Lower glume;d. Upper glume;e.&f. Lemma;G.Palea;h. LodiCule; i. Pistil; j. Stamen.

FiG.41. Distribution ofTripogon ravianus Sunil & Pradeep,T.sivarajanii Sunil and T.trifidus Munro ex Hook.f.in India [drawn using ESRI (2011) ArCGIS Desktop: Release 10].