Henckelia wayanadensis Janeesha & Nampy, 2020

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 : 87-93

publication ID	https://doi.org/10.22244/rheedea.2020.30.01.03
persistent identifier	https://treatment.plazi.org/id/5251830B-FFD7-0902-FD3F-FF49FE9B5CC2
treatment provided by	Felipe
scientific name	Henckelia wayanadensis Janeesha & Nampy
status	sp. nov.

Treatment

Henckelia wayanadensis Janeesha & Nampy View in CoL , sp. nov. FiGS. 22 View FiG & 23 View FiG a 1-i1 View FiG

Henckelia wayanadensis is morphologically similar to H. fischeri , but can be readily identified by its elliptic to widely elliptic leaves (vs. ovate), ovate hispid bracts (vs. lanceolate tomentose bracts), small flowers 12–14 × 6.7–11 mm (vs. large flowers 11–17 × 9–22 mm), and purple glands on the ovary (vs. hyaline glandular hairs on the ovary).

Type: INDIA, Kerala, Wayanad district, Kaduvakuzhi hill top, 1200 m, 08.07.2016, A.P. Janeesha & Santhosh Nampy 137672 (holo CALI!; iso MH!)

Perennials, rosette-forming, herbs with rootstocks. Roots adventitious, thin. Leaves 8–20, basal, usually in whorls of four; petioles 4–11.5 cm long, pubescent, winged; wings 3–8 mm broad; laminae elliptic to widely elliptic, 8–19.2 × 6–12 cm, obtuse to slightly acute at apex, attenuate at base, margins doubly crenate, ultimate segments irregular, first crenation very deep, surfaces usually rugose, white tomentose on both surfaces, becoming less so with age; veins 6–8 on each side, much branched and conspicuous beneath. Cymes axillary, 4–10 per plant, 3–5 times divided, 35–63-flowered; peduncles terete, 23–30 cm long, green-pale reddish brown, tomentose; bracts two at each branching point, ovate, 5.5–6.6 × 1–2 mm, slightly acute at apex, margin entire, hispid, green; pedicels terete, 4–26 mm long, narrow, tomentose. Flowers 12–14 × 6.7–11 mm, held horizontal. Calyx 5- partite, very deeply divided or basally connate; lobes linear to ovate-elliptic, unequal, posterior lobe small, 2.7–3.4 × 0.5–0.9 mm, others 3.55–4.35 × 0.8–1.4 mm, green, obtuse at apex, margins entire, glandular hairy. Corolla zygomorphic, ventricose, two lipped, glandular hairy outside, glabrous inside; tube 5–9 × 3.4–4.5 mm, dark to pale lilac with a yellow blotch at the throat, swollen towards the mouth; lobes widely ovate, rounded at apex dark to pale lilac, upper lip of two lobes, 3.7–4 × 4–5.1 mm, lower lip of three lobes, 3.9–4.4 × 4.2–5.8 mm. Stamens 2, adnate to the base of corolla, included; filaments 3.3–4.3 mm long, glabrous, yellow; anthers reniform, 1.2–1.7 × 0.4–0.76 mm, milky white to cream. Staminodes 2; filaments 1.3–3 mm long, hyaline, glabrous; antherodes a small knoblike structure. Ovary ovoid to oblong, 2.7–3.5 × 0.9–1.3 mm, green, glandular hairy, gland tip purplish; style terete, 2.2–3.6 mm long, green, glabrous towards apex, glandular hairy towards base; stigma obliquely subcapitate, 0.4–0.5 × 0.22– 0.24 mm, papillate, pale green. Capsules cylindrical, straight or slightly curved, 20–22 × 1.6–2 mm, plagiocarpic, dehiscing loculicidally long the dorsal side, reddish brown, glandular, hispid, with persistent stigma and calyx. Seeds numerous, elliptic, 0.65–0.72 × 0.20–0.24 mm, truncate at both; testa dark brown, reticulate.

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

Etymology: The species epithet ‘ wayanadensis’ refers to the locality ‘Wayanad’, the floristically rich district of Kerala in which the new taxon was discovered.

Habitat: In rock crevices, usually at an elevation above 900 m, in association with Parahemionitis sp. ( Pteridaceae ), Cyanotis sp. ( Commelinaceae ) and some moss and grass species.

Distribution: Hitherto known only from the type locality ( Fig. 26 View FiG ).

Specimens examined: INDIA, Kerala, Wayanad district, Kaduvakuzhi hill top, 08.07.2016, A.P. Janeesha & P.G. Arunkumar 137671; Ibid., 15.09.2016, A.P. Janeesha & K. Haseem 137690; on the way to Kaduvakuzhi , 500 m away from Adivaram, 08.07.2016, A.P. Janeesha & P.G. Arunkumar 137670 (CALI) .

Conservation status: The new species is currently known only from one locality with three subpopulations in an unprotected area, separated by a distance of 50–60 meters, with a total of 61 mature plants. There is the possibility of disturbances in the future due to human activities, where local peoples are exploring the area for wood, forage grasses etc. The Area of Occupancy (AOO) is likely to be less than 10 km 2. Therefore the species is categorized as Critically endangered (CR),

B2ab(iii,iv,v) according to IUCN criteria ( IUCN, 2019).

Henckelia wightii (C.B.Clarke) A.Weber & B.L.Burtt, Beitr. Biol. Pflanzen View in CoL 70: 359. 1998 [“1997”]. Didymocarpus rottleriana Wall., Wight, Icon. Pl. Ind. Orient. View in CoL 4: 24. t. 1348. 1848. Didymocarpus rottlerianus Wall. ex R.Br. var. wightii C.B.Clarke View in CoL in A.DC. & C.DC., Monogr. Phan. 5: 101. 1883, C.B.Clarke in Hook.f., Fl. Brit. India 4: 354. 1885 [“1884”]. Didymocarpus wightii (C.B.Clarke) Gamble, Fl. Madras View in CoL 2: 989. 1924; A.N.Henry et al., Fl. Tamil Nadu Ind., Ser I: Analysis 2: 133. 1987; M.Ahmedullah & M.P.Nayar, Endemic Pl. Indian Region 1: 143. 1987; Sasidh., Biodivers. Doc. Kerala Part 6: Fl. Pl. 332. 2004; T.S.Nayar et al., Fl. Pl. Kerala 343. 2006, Fl. Pl. Western Ghats 1: 529. 2014. Lectotype (designated here): INDIA, Tamil Nadu, Tirunelveli district, Shevghery, Courtallam, s.d., Wight 2323 (K [K000858201 digital image!]; isolecto: E [E00155179 digital image!]).

Didymocarpus sivagiriensis Rajakumar, Selvak., S.Murug. & Chellap., Indian J. Forest. View in CoL 32(3): 481. 2009; T.S.Nayar et al., Fl. Pl. Western Ghats 1: 527. 2014, syn. nov. Henckelia sivagiriensis (Rajakumar, Selvak., S.Murug. & Chellap.) E.S.S. Kumar, Polish Bot. J. View in CoL 59(1): 149. 2014. Type: INDIA, Tamil Nadu, Tenkasi district, Thalaiyanai reserve forest, s.d., Rajakumar , Selvakumari , Murugesan & Chellapperumal 829 (holo JCH). FiGS. 24 View FiG & 25 View FiG

Perennials, rosette-forming, hairy herbs with rootstocks. Roots adventitious, thick. Leaves 12– 20, basal, in whorls of 4–7, sessile to sub-sessile; laminae spatulate-obovate to elliptic, 3.8–10.7 × 1.6–3.6 cm, obtuse to rounded at apex, attenuate at base, margins slightly crenate and undulate, surfaces smooth, velvety, with white woolly hairs on both surfaces, but more so on the younger leaves and on lower veins, becoming less so with age; veins 4–6 on each side, much branched and conspicuous beneath. Cymes axillary, dense; 2–6 per plant, 3–4 times divided, 5–13-flowered; peduncles terete, 10– 18 cm long, greenish, glandular hairy; bracts two at each branching point, minute, completely woolly, c. 2 mm long; pedicels terete, 9–18 mm long, narrow, glandular hairy. Flowers 11–15 × 10– 14 mm. Calyx 5-partite, very deeply divided; lobes oblong-lanceolate, unequal, posterior lobe small, 1.8–2.1 × 0.45–0.6 mm, other lobes, 2–3 × 0.6–0.8 mm, slightly acute at apex, margins entire, with white woolly hairs on the upper side. Corolla zygomorphic, ventricose, two lipped, glandular hairy outside, glabrous inside; tube lilac to pale lilac with a yellow patch in the throat; lobes orbicular, ovate to rounded at apex, lilac to pale lilac, upper lip of two lobes, lower lip of three lobes. Stamens 2, adnate to the base of corolla, included; filaments c. 2 mm long, glabrous; anthers reniform, glabrous. Staminodes 3 (sometimes 2); filaments c. 1.2 mm long, glabrous; antherodes not seen. Ovary ovoid to cylindrical, c. 2.5 mm long, covered with dense white woolly hairs, completely enclosed within calyx; style terete, c. 1.3 mm long, glabrous; stigma obliquely subcapitate, papillate, pale green. Capsules linear-cylindrical, straight, 11–17 mm long, plagiocarpic, dehiscing loculicidally along the dorsal side, green, tomentulose with persistent stigma and calyx. Seeds numerous, reticulate.

Flowering & fruiting: Flowering from July to October and fruiting from August to November.

Habitat: On moist rocks.

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

Specimens examined: INDIA, Kerala, Idukki district, Karadippara-Munnar , 25.07.2013, A.P. Janeesha & K.M. Manudev 134203 (CALI) . Tamil Nadu, Erode district, Attamalai hills, 24.07.1988, N. Venkatasubramanian 1424 (FRC); Tenkasi district , New Courtallam, 16.07.2015, A.P. Janeesha, S. Resmi & P.G. Arunkumar 137628 (CALI); Virudhunagar district , Kendiparai to Cumbumedu-Ayyanarkovil, 23.09.1971, E. Vajravelu 38720; Mudaliarattu, 11.12.1971, E. Vajravelu 39339 (MH) .

Conservation status: The species is known from four districts in Kerala and Tamil Nadu where a total of five localities were known. The Extent of Occurrence (EOO) is estimated to be c. 2100 km ² and Area of Occupancy (AOO) is 20 km ². During a period between 2013 and 2017, one of the authors (JAP) visited four localities except Ayyanarkovil and was unable to observe more than 5 mature plants in two localities, i.e., Munnar and Courtallam. Thus, a decline in number of localities from five to two over five years has been observed, in (1) EOO (ii) AOO; (iv) number of locations or subpopulations and (v) number of mature individuals. Because of the very low number of plants found, we consider this species to be Critically endangered (CR), D according to IUCN guidelines, with a high risk of extinction in the near future ( IUCN, 2019).

Notes: Rajakumar et al. (2009) described Henckelia sivagiriensis (as Didymocarpus sivagiriensis Rajkumar, Semvak., S.Murug. & Chellap. ) and differentiated it from H. wightii by its longer leaves, presence of glandular hairs, longer dichotomously branched scapes, bluish corolla, puberulous style and longer capsules. Critical examination of specimens and protologues of both these taxa revealed that the characters outlined for separating the former from the latter are intergrading (see description above) and hence H. sivagiriensis is reduced to synonymy of H. wightii .

Typification: Wight described this species based on material collected from the Shevghery hills, Courtallam in Tamil Nadu. Since Vitek et al. (2000) cited only syntypes , it cannot be considered a lectotypification. Two sheets of Wight’s materials were located, while searching for the type specimens, one each in E (E00155179) and K (K000858201). The sheet K000858201 has an HRWP label and bears a field label, “Shevghery hills August 1836 ” and an annotation by Clarke “the specimen from which Wight Ic. 1348 was taken”. The sheet itself has the no. 2323/ 1837 in the bottom left hand corner. The sheet in E (E00155179) has an HWP label annotated “ Didymocarpus rottlerianus var. wightii ” and “ Herb . Wight. propr. n. 2679” in the top right hand corner and another in the lower left hand corner “1837, No 2323”, presumably referring to the year 1837. The specimen at K (K000858201) used for illustrating this species by Wight is selected here as the lectotype and the other at E (E00155179) as the isolectotype.