Henckelia pradeepiana Nampy, Manudev & A.Weber., Rheedea

A. P., Janeesha & Nampy, S., 2020, A taxonomic revision of Henckelia (Gesneriaceae) in South India with a new species, one new combination and seven lectotypifications, Rheedea 30 (1), pp. 48-95 : 82-87

Henckelia pradeepiana Nampy, Manudev & A.Weber., Rheedea 22(2): 119. 2012; T.S.Nayar et al., Fl. Pl. Western Ghats 1: 529. 2014. T y p e: INDIA, Kerala, Kozhikode district , Muthappanpuzha, N 11̊26.6992', E 076̊05.2882', 470 m, 19.08.2010, Santhosh Nampy & K.M. Manudev 3102 (holo CALI!; iso DEV!, W!). FiG. 19

Perennating tuberous herbs. Tubers 1–2.5 cm diam., discoid. Leaves usually 1, rarely up to 3; petioles 1.8–5.6 cm long, sparsely glandular hairy, not winged; laminae broadly ovate or elliptic, oblong-ovate, 9–16 × 5.5–9 cm, acute at apex, slightly oblique or cordate at base, margins entire to serrulate, glabrous above, glandular hairy below, membranaceous, glandular hairy on the margins, surfaces smooth; veins usually 7 on each side, much branched and conspicuous beneath. Cymes axillary, 1–3 per plant, 1–6 times divided, 2–19-flowered, glandular hairy; peduncles terete, 5–20 cm long, green; bracts two at each branching point, lanceolate to triangular, 4.8–6.1 × 1.2–1.7 mm, acute at apex, margin entire, slightly hairy; pedicels terete, 1–3.8 cm long, slender, glandular hairy. Flowers c. 10 × 7 mm. Calyx 5-partite, basally connate; lobes ovate-lanceolate, unequal, posterior lobe small, 3–4.1 × 1–1.25 mm, others 4.3–7 × 1.3– 2.1 mm, keeled, blunt at apex, margins entire, green, glabrous. Corolla campanulate, two lipped, glabrous inside and outside (but with a few hairs at the corolla mouth); tube 4–5.4 × 5.2–5.6 mm, lilac to pale lilac with a yellow patch in the throat, with 7–10 purplish streaks; lobes ovate to rounded at apex, lilac to pale lilac, upper lip of two lobes, 2– 3.1 × 3.4–4.51 mm, lower lip of three lobes, 3–3.8 × 3.6–4.3 mm. Stamens 2, adnate to the base of corolla, included; filaments 2.4–3.3 mm long, glabrous, greenish yellow; anthers reniform, 1.3– 1.5 × 0.53–0.73 mm, milky white, glabrous. Staminodes 2; filaments 1–1.2 mm long, hyaline, glabrous; antherodes ovate to oblate, c. 0.31 × 0.3 mm. Ovary ovoid, 2–2.4 × 1.35–1.75 mm, green, glabrous; style terete, 4–5.22 mm long, green, glabrous; stigma subpeltate, lower lip strongly expanded and slightly emarginate at apex, 1.7–2.1 × 0.5–0.87 mm, papillate, yellow to yellowish green. Capsules ovoid to subglobose, 5.6–6.3 × 5–6 mm, plagiocarpic, dehiscing by a longitudinal slit on the upper side, greenish brown, with persistent calyx and a prominent beak. Seeds numerous, elliptic, 0.4–0.52 × 0.15–0.2 mm, acute at both ends; testa dark brown, reticulate.

Flowering & fruiting: Flowering from July to August and fruiting from August to September.

Habitat: On moist rocks and mountain slopes, found in association with mosses and ferns.

Distribution: Endemic to the southern Western Ghats ( Fig. 20 ).

Specimens examined: INDIA, Kerala, Kozhikode district , Muthappanpuzha, N 11̊26.6992', E 76̊05.2882', 470 m, 18.07.2010 , K.M. Manudev 3022 (DEV); Ibid., 19.08.2010, A.K. Pradeep 90089 (CALI); Ibid., 19.08.2010, K.M. Manudev & Santhosh Nampy 3105; Ibid., 17.09.2011, Santhosh Nampy & K.M. Manudev 4547 (DEV); Ibid., 12.08.2014, A.P. Janeesha & Santhosh Nampy 134287, 134288; Ibid., 15.06.2015, A.P. Janeesha & S. Resmi 137624; Muthappanpuzha-Kundanthode, 15.06.2015, A.P.

84 A taxonomic revision of Henckelia (Gesneriaceae) in South India

Janeesha & S. Resmi 137623; way to Vellarimala- Olichuchattam, N 11̊25.7842', E 76̊05.1732', 1160 m, 19.09.1997, A.K. Pradeep 56009 (CALI).

Conservation status: The species is currently known only from the type locality which is an unprotected area, with two subpopulations separated by a distance of 2 kilometres. The locality has a total of 79 mature plants, with the possibility of future disturbances due to human activities since the area is near a stream which is used by local people for their daily needs. The Area of Occupancy (AOO) is less than 10 km ². The species may be categorized as Critically endangered (CR), B2ab(ii,iii,iv,v), D ( IUCN, 2019) .

Notes: This species has several unusual features not found in any other Henckelia species in South India or the genus as a whole. This is the only species of Henckelia having tubers to enable the plants to overcome unfavourable conditions or periods. The plants usually have only one leaf, but sometimes up to 3 arranged alternately. The stigma is unusual for South Indian Henckelia in that they are chiritoid, with the upper lobe reduced and the lower one undivided and linguate ( Weber et al., 2011; Manudev et al., 2012). The capsules are globose in contrast to the linear to cylindrical ones in other South Indian Henckelia species or any other species in the genus, but are plagiocarpic and dehisce similar to other South Indian Henckelia . They are reminiscent of those found in species of Loxocarpus, another genus previously included in Henckelia (Weber & Burtt, 1998[“1997”]) but recently resurrected ( Weber et al., 2011; Middleton et al., 2013).

Henckelia repens (Bedd.) A.Weber & B.L.Burtt, Beitr. Biol. Pflanzen 70: 354. 1998 [“1997”]; T.S.Nayar et al., Fl. Pl. Western Ghats 1: 529. 2014. Didymocarpus repens Bedd., Icon. Pl. Ind. Or. 1: 24. t. 120. 1874; C.B.Clarke in Hook.f., Fl. Brit. India 4: 354. 1885 [“1884”]; Rama Rao, Fl. Pl. Travancore 295. 1914; Gamble, Fl. Madras 2: 987. 1924; M.Ahmedullah & M.P.Nayar, Endemic Pl. Indian Region 1: 143. 1987; A.N.Henry et al., Fl. Tamil Nadu Ind., Ser I: Analysis 2: 133. 1987; M.Mohanan & A.N.Henry, Fl. Thiruvananthapuram Dist. 338. 1994; Gopalan & A.N.Henry, Endemic Pl. India 121. 2000; M.Mohanan & Sivad., Fl. Agasthyamala 496. 2002; Sasidh., Biodivers. Doc. Kerala Part 6: Fl. Pl. 332. 2004; T.S.Nayar et al., Fl. Pl. Kerala 342. 2006. Rottlera repens (Bedd.) Kuntze, Revis. Gen. Pl. 2: 477. 1891. Lectotype (designated by Vitek et al., 2000): INDIA, Tinnevelly and Travancore hills, 3000 feet elevation, 09.1868, Beddome 46 (K [K000858200 digital image!]; isolecto MH [36684!, 36680!]). FiG. 21

Perennial creeping herbs, rooting at nodes and also along the internodes, hairy throughout. Roots adventitious. Stems slender, terete, hairy; internodes 6–12 cm long. Leaves two per node, one is highly reduced to a scale; petioles 3.5–18 cm long, not winged; laminae broadly ovate to sub-orbicular, 5.2–10 × 5–8.3 cm, acute at apex, cordate at base, margins doubly crenate, hairy; veins usually 5–6 on each side, much branched and conspicuous beneath. Cymes few-flowered, usually one from each node, 1–3 times divided, 2–4-flowered; peduncles 4–14.5 cm long, terete, green-pale reddish brown, hairy throughout; pedicels 5–10 mm long, terete, narrow, glandular hairy. Flowers 12–20 × 8–15 mm. Calyx 5-partite, very deeply divided or basally connate; lobes broadly lanceolate, slightly acute at apex, reddish brown, margins entire, hairy, unequal, posterior one small, 3.4–3.7 × 0.7–0.83 mm, others 3.8–4.2 × 0.83–1 mm. Corolla zygomorphic, ventricose, two lipped, glandular hairy outside, glabrous inside; tube 12– 13 × 4.5–5.4 mm, dark to pale lilac with a yellow blotch at the throat; lobes elliptic to oblong, rounded at apex, dark to pale lilac, upper lip of two lobes, 4.1–4.9 × 4.7–5.2 mm, lower lip of three lobes, 5–6.65 × 4.3–5.47 mm. Stamens 2, adnate to the base of the corolla, included; filaments 7.5–8 mm long, broad and hairy at the middle, not geniculate, yellow at the middle, other parts milky white; anthers reniform, 2–2.1 × 0.5–0.7 mm, purple coloured except the cohering region of the lobes and also the region surrounding the connective. Staminodes 2; filaments 3.6–4.1 mm long, hyaline, hairy towards the middle; antherodes trilobed, 0.42–0.44 × 0.36–0.37 mm, prominent. Ovary narrowly ovoid, tapering to a style, c. 7.2 × 1.21 mm, green towards the base and reddish green towards the distal part, eglandular hairy; style terete, 4–4.4 × 0.5 mm long, hyaline, eglandular hairy throughout; stigma oblique, subpeltate, 1.7 × 1.23 mm, glabrous. Capsules linear, straight, 20–22 × 2–2.2 mm, plagiocarpic, dehiscing loculicidally along the dorsal side, reddish brown, hairy, with persistent stigma. Seeds numerous, elliptic, 0.49– 0.59 × 0.21–0.24 mm, slightly acute at apex, truncate at base; testa dark brown, reticulate.

Flowering & fruiting: Flowering from (May) June to October and fruiting from August to December.

Habitat: Henckelia repens is found as an undercover in moist mixed evergreen and deciduous forests, in association with Elatostema sp. , Pouzolzia sp. (both Urticaceae ), Adiantum philippenes L. ( Pteridaceae ), Christella sp. ( Thelypteridaceae ), Selaginella sp. ( Selaginellaceae ) and some grass species.

Distribution: Endemic to the southern Western Ghats ( Fig. 26 ).

Specimens examined: INDIA, Kerala, Kollam district, Kolatoor, s.d., s.coll. 1293 (MH); Thiruvananthapuram district , Agasthyamala- Mutththatti , 06.06.2014, K.M. Manudev, A.P. Janeesha & Santhosh Nampy 138940 (CALI); Athirumala, 12.08.1988, N. Mohanan 4227 (TBGT, CALI); Ibid., 07.06.2014, K.M. Manudev, P.G. Arun Kumar & A.P. Janeesha 138936; Attayar, 13.05.1988, N. Mohanan 9614; Bonaccord, 27.04.1993, A. Nazarudeen 17128 (CALI); Ibid., 21.12.1987, N. Mohanan 9066 (TBGT, CALI); forest near Bonaccord, 21.08.1975, J. Joseph 46470; Ibid., 02.10.1973, J. Joseph 44493 (MH); Chemungi, s.d., Rajkumar 11775; Ibid., 18.08.1992, E.S. Santhosh Kumar & M. Abdul Jabbar 14447; Ibid., 11.08.2011, P.M. Sheeba 66275 (TBGT); Pandimottai, 19.05.1979, M. Mohanan 61853 (MH); Pidichathamparamal, 31.05.2001, Non Wood F orest Product’s (NWFPs) Team 46274; Pinarummodu, 25.09.2008, C.G. Vishnu 64727 (TBGT); Ponmudi, 28.11.2012, A.P. Janeesha, P.M. Shahina & K.M. Manudev 134240; Ibid., 10.10.2014, M.G. Vimal, Prasad & A.P. Janeesha 137603; s.loc., 21.12.1987, N. Mohanan 9066 (CALI) . Tamil Nadu, Tirunelveli district, Ambasamudram to Kannikkatti , 31.12.1977, K.M. Matthew 15627; Ibid., 01.01.1978, K.M. Matthew 15796 (RHT); Chittar river-way to Agasthyamalai, 22.08.1963, A.N. Henry 16971; Kannikkatti, 12.06.1899, C.A. Barber 396; Kannikkatti to Kalivayalpil, 31.05.1901, C.A. Barber 3002; Papanasam hills, 1867, R.H. Beddome s.n.; Valayar forest , 11.07.1976, P. Bhargavan 47445; way to Ainthuthalai, 14.10.1989, R. Gopalan 90662; way to Pothgai malai, 16.10.1989, R. Gopalan 91605; way to Kalivarapil, 23.01.1991, R. Gopalan 94658; s.loc., 1877, R.H. Beddome s.n. (MH)); s.loc., s.d., R.H. Beddome 5008, 5805 (BM digital image) .

Conservation status: The species is distributed in 4 districts in southern Kerala and southern Tami Nadu and where seven locations are known. Only five of these fall in protected areas. The Extent of Occurrence (EOO) is calculated to be c. 600 km 2 and the Area of Occupancy (AOO) is 28 km 2. During field studies, the authors observed a total of only 52 mature plants at four locations. This might indicate that the species occurs with very few individuals in total and should belong in the Endangered category (EN), D ( IUCN, 2019) .

Notes: Henckelia repens is the only creeping species in South India while the other species, H. burttii D.J.Middleton & Mich.Möller , with a very similar habit is found in Northeast India (Burtt & Panigrahi, 1965; Wood, 1974). Henckelia repens has a longer corolla tube (up to 1.5) compared to other South Indian species. Beddome’s illustration (Icon. Pl. Ind. Or. 1: 24. t. 120. 1874) and drawings on the type sheet at K differ with the protologue in two points. The anthers are cohering in the specimens but they are drawn in the icon and on the illustration on the type sheet as non-coherent. Similarly, the filament is broad except at the apex, but it is drawn as narrow along its entire length in the type sheet and broad at the basal region in the icon.

Figures

FiG. 19. Henckelia pradeepiana Nampy, Manudev & A.Weber: a. Habit and habitat; b. A portion of the inflorescence; c. Flower; d. Calyx; e. Calyx with pistil; f. Bract; G. Stamens; h. Staminode; i. Pistil; j. Dehiscing capsule; k. Seeds (from A.P. Janeesha & Santhosh Nampy 134287).

FiG. 20. Distribution of Henckelia ovalifolia (Wight) A.Weber & B.L.Burtt and H. pradeepiana Nampy, Manudev & A.Weber in South India (drawn using QGIS v.3.12.1).

FiG. 21. Henckelia repens (Bedd.) A.Weber & B.L.Burtt: a. Habit and habitat; b. Flowering creeping shoot; c. Flower; d. Calyx; e. Calyx with pistil; f. Stamens; G. Staminode; h. Pistil; i. Stigma; j. Capsule; k. Seeds (a & b from K.M. Manudev,A.P. Janeesha & Santhosh Nampy 138940; K.M. Manudev, P.G. Arunkumar & A.P. Janeesha 138936).

FiG. 26. Distribution of Henckelia repens (Bedd.) A.Weber & B.L.Burtt, H. wayanadensis Janeesha & Nampy and H. wightii (C.B.Clarke) A.Weber & B.L.Burtt in South India (drawn using QGIS v.3.12.1).