First record of Elytraria acaulis ( L . f . ) Lindau ( Acanthaceae ) from the Kerala state and its distribution extension in India

Elytraria acaulis (L.f.) Lindau (family Acanthaceae) is a perennial herb that is distributed in tropical Africa and Peninsular India. In India, this plant has been recorded from Northern Circar, Deccan, and Carnatic regions, on the eastern side of Peninsular India. We present here a new record from the Walayar Reserve Forest in Palakkad District, Kerala, which is the first known occurrence of this species from the western side of the peninsula. This species is added to the flora of Kerala state.

Elytraria Michx. is a genus belonging to the subfamily Nelsonioideae within the Acanthaceae that is represented by 22 species of herbaceous plants that are distributed in tropical Africa, Madagascar, the Indian Subcontinent and the New world (Daniel 1997;Wenk and Daniel 2009).Elytraria acaulis (L.f.) Lindau, is a nearly stemless perennial herb with a distribution that encompasses parts of tropical Africa and the Indian Subcontinent (Hyde et al. 2014).Outside of India, E. acaulis occurs in Ghana, Nigeria, Democratic Republic of Congo, Angola, Botswana, Somalia, Uganda, Kenya, Tanzania, Malawi, Mozambique, Zambia, Zimbabwe, and South Africa (Wenk and Daniel 2009;Hyde et al. 2014).
Elytraria acaulis has been recorded in India from Northern Circar, Deccan, and Carnatic regions (former administrative divisions of the Presidency of Madras; Gamble and Fischer 1936) and Peninsular India (Mathew 1983;1999;Karthikeyan and Kumar 1993;Pullaiah et al. 2000).It is known from grasslands of Rajastan (western India; Jain et al. 2005;Krishna et al. 2014), Haryana (northern India;Kumar and Singh 2013), and Madhya Pradesh (central India;Nema et al. 2012).Nowadays, the Northern Circar region is part of coastal Andhra Pradesh and Ganjam of Odisha; the Deccan region is in Karnataka and Andhra Pradesh states; and the Carnatic region is part of Tamil Nadu, southeast Karnataka, parts of Andhra Pradesh and northeast Kerala states.Elytraria acaulis was not reported by Vajravelu (1990) from Palghat district, Kerala state on the western side of the Peninsular India, nor is the plant mentioned by Sasidharan 2004.Hence, in this note, E. acaulis is added to the flora of Kerala state.
During fieldwork in Walayar Reserve Forest (10°51ʹ 37ʺ N, 076°49ʹ47ʺ E), Kerala state, India (Figure 1), June 2014, we collected samples of a plant that we recognized as new.Specimens were brought to the lab and identified using Gamble and Fischer (1936).Our identification of our specimens as Elytraria acaulis was confirmed by comparing our specimens with the collections in the Herbarium of Botanical Survey of India, Southern Circle, Coimbatore, Tamil Nadu.We made further intensive field surveys over three days in the Walayar Reserve Forest to understand the habitat and distribution of E. acaulis in the area.Additional samples were collected and prepared for the herbarium.Voucher specimens [V.S. Ramachandran and M. Remesh 121(CESH)] are deposited in the herbarium of Botanical Survey of India, Southern Circle, Coimbatore.

Specimens examined:
India: Kerala: Palakkad Dist rict: Walayar: Nadupathi,V.S. Rama chandran and M. Remesh 121 (CESH!); Tamil Nadu: Kanyakumari We collected Erytraria acaulis from the undergrowth of a Teak (Tectona grandis L.f.) plantation near the tribal hamlet at Nadupathi in the Walayar Reserve Forest.Here, this species prefers partial shade and loamy soil.We made a thorough search in the surrounding area and found that this species is distributed in an area less than 2 km 2 between the Walayar River and one of its tributaries (Figure 2).Our new record is at the northern fringe of the Palghat Gap, in the foothills of the Western Ghats, and nearly 100 m away from the Walayar River on its western side.The river forms the border of Kerala and Tamil Nadu states.Thus, we report the first known occurrence of this species from Kerala.Our new record also represents the westernmost occurrence in India.Our Walayar record is ca.65 km south of Thekkampatti (K.Elytraria acaulis is characterized as follows: Leaves obovate, crenate, obtuse, 15-17 cm long, 4-6 cm wide, the bases surrounded by woolly hairs, alternate, crowded and subradical (Figure 2).Flowers small, white in colour, in simple or branched spikes.Scapes 10-20 In the Walayar Reserve Forest, we found E. acaulis to be entirely within the Teak plantation.This area is prone to ground fire every year; local people use fire for various reasons but the major reason is to collect seeds of the Silk Cottom Tree (Bombax insigne Wall.).Erytraria acaulis is perennial and ground fire can be a threat for survival of these plants at Walayar.We observed that, when rains stop and the soil dries, plants shows signs of wilting and drying, perhaps a result of the annual fires.This is the current conservation concern for the species at Walayar.However, E. acaulis has a wider distribution in India, so the local threat to the species at Walayar may not apply to other Indian locations.

Figure 1 .
Figure 1.Location of Walayar Reserve Forest in Kerala, India and new record of Elytraria acaulis.The Walayar River forms the border of Kerala and Tamil Nadu states.