Saturday, July 30, 2016

[Botany • 2016] Henckelia wijesundarae • A New endemic Species (Gesneriaceae) from Sri Lanka, and lectotypification of Chirita walkerae and C. walkerae var. parviflora

 Henckelia wijesundarae 
Ranasinghe & Mich. Möller

A new species, Henckelia wijesundarae, endemic to Hiniduma, Galle, Sri Lanka, is described and illustrated. Diagnostic features of the new species are discussed and compared to the closely allied species H. walkerae. Based on fieldwork studies, we propose an IUCN conservation status of Critically Endangered (CR) for H. wijesundarae. At the same time we lectotypify the names Chirita walkerae (the basionym of H. walkerae) and C. walkerae var. parviflora (treated here in the synonymy of H. wijesundarae).

Keywords: Gesneriaceae, Henckelia, Chirita, Henckelia walkerae, Chirita walkerae, Chirita walkerae subsp. parviflora, Chirita walkerae var. parviflora, new species, lectotype, Sri Lanka, Hiniduma

Henckelia wijesundarae Ranasinghe & Mich. Möller, sp. nov. — Fig. 3 & 4.

Holotype: Sri Lanka, Southern Province, Galle District, Hiniduma, forest behind Nugagala Monastery, 208 m, 26 Jul 2013, Subhani Ranasinghe & Tharanga Wijewickrama 31 (PDA; isotypes: E, K).

= Chirita walkerae [“walkeri”] var. parviflora C. B. Clarke in Candolle & Candolle, Monogr. Phan. 5(1): 112. 1883 = Chirita walkerae [“walkeri”] subsp. parviflora (C. B. Clarke) W. L. Theob. & Grupe in Ceylon J. Sci., Biol. Sci. 10: 70. 1972. — Lectotype: see p. 220. — Chirita walkerae [“walkeri”] var. “β” in Thwaites, Enum. Pl. Zeyl.: 207. 1864.

Diagnosis — Henckelia wijesundarae Ranasinghe & Mich. Möller differs from H. walkerae (Gardner) D. J. Middleton & Mich. Möller by its less dense short straight hairs on the adaxial and abaxial leaf surfaces, inconspicuous hydathodes (vs prominent ones in H. walkerae) on shallowly crenulate (vs serrate) leaf margins, 8–10 pairs (vs 12–(14) pairs) of lateral veins, calyx less than 2 cm long (vs more than 2 cm long), calyx lobes keeled, with a sharp ridge along the middle axis and hairs aggregated along this ridge (vs keel inconspicuous, hairs scattered throughout calyx lobe), shorter corolla, 3–4 cm long (vs 4–6 cm long), white (vs deep purple) corolla lobes, toothed (vs un toothed) filaments, distinctly spatulate (vs cuneate-truncate) stigma, and shorter fruit, 6–7 cm long (vs 8–13 cm long).

Phenology — Flowering specimens were collected from July to September; fruiting time is September to November.

Distribution and ecology — Currently known from Hiniduma, Galle, in SW Sri Lanka, at altitudes of 200–300 m, growing in shade on wet rock outcrops in lowland rainforest patches.

Eponymy — The specific epithet wijesundarae honours the great botanist, scientist and former Director General of the Botanic Gardens in Sri Lanka, Dr. Siril Wijesundara.

Fig. 4. Henckelia wijesundarae – A: habit; B: corolla front view; C: corolla longitudinal section; D: two inflorescences; E: two stamens with toothed filaments and coherent anthers and two lateral staminodes; F: leaf abaxial (left) and adaxial (right) surfaces; G: calyx showing lobes divided less than ½ length of calyx. 

 Subhani Ranasinghe, Richard Milne, Rohana Jayasekara, Sumudu Rubasinghe and Michael Möller. 2016. Henckelia wijesundarae (Gesneriaceae), A New endemic Species from Sri Lanka, and lectotypification of Chirita walkerae and C. walkerae var. parvifloraWilldenowia. 46(2); 213-224. DOI: 10.3372/wi.46.46202