A NEW SUBSPECIES OF DIMERIA HOHENACKERI HOCHST . EX MIQ . ( POACEAE ) FROM INDIA

A new subspecies, viz. Dimeria hohenackeri Hochst. ex Miq. subsp. kodaguensis Kiran Raj, Sivad. & Dileep from South Karnataka of the Southern Western Ghats in Peninsular India is described and illustrated. It mainly differs from D. hohenackeri Hochst. ex Miq. subsp. hohenackeri in having mat-forming habit with leaves crowded at culm-base, spikelets 3–4 mm long and glumes not widely divergent during anthesis. Introduction The palaeotropical genus Dimeria R. Br. with about 65 species is mainly adapted to humid or semi-arid habitat and distributed from Indian subcontinent to Malesiana, northern Australia and Madagascar (Bor, 1960; Clayton et al., 2006; Kiran Raj and Sivadasan, 2008; Kiran Raj et al., 2013, 2015a; Teerawatananon et al., 2014). The genus is most peculiar in the tribe Andropogoneae by its solitary, laterally compressed spikelets and flat or filiform rachis without joints. Majority of the taxa (ca. 34 spp., 3 subspp. and one variety) are confined to Peninsular India with 26 endemics (Kiran Raj et al., 2015b). Moreover, the monotypic genus Nanooravia Kiran Raj & Sivad. belonging to the bitypic subtribe Dimeriinae, is also endemic to this region, indicating it to be the centre of diversity of the subtribe (Kiran Raj, 2008; Kiran Raj et al., 2015b).The infra-tribal classification of Andropogoneae and especially the systematic position of Dimeriinae are enigmatic and still controversial (Clayton and Renvoize, 1986; Simon, 2007) due to the lack of sufficient data from the representative taxa. Interesting specimens of Dimeria were collected during botanical explorations in Southern Western Ghats in Karnataka, India, and detailed study showed them to be representing new taxon related to Dimeria hohenackeri. It is described herein as a new subspecies of Dimeria hohenackeri Hochst. ex Miq. The species belongs to Dimeria sect. Capillares, with distribution extending from lowland grassy slopes of Western Ghats in Maharashtra through Karnataka to Kerala in Peninsular India. Dimeria sect. Capillares is distinguished by capillary raceme-rachis with distantly arranged spikelets, and is endemic to Indian subcontinent (Kiran Raj et al., 2015b). Detailed description of the new subspecies with other relevant information including illustration is provided for easy identification of taxon in field. A key to the subspecies of D. hohenackeri in India is also provided. *Corresponding author. Email: drmsivadasan@gmail.com Department of Botany & Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh– 11451, Kingdom of Saudi Arabia. Department of Botany, Regional Institute of Education (RIE), Mysore-570 006, Karnataka, India.


Introduction
The palaeotropical genus Dimeria R. Br. with about 65 species is mainly adapted to humid or semi-arid habitat and distributed from Indian subcontinent to Malesiana, northern Australia and Madagascar (Bor, 1960;Clayton et al., 2006;Kiran Raj and Sivadasan, 2008;Kiran Raj et al., 2013, 2015a;Teerawatananon et al., 2014).The genus is most peculiar in the tribe Andropogoneae by its solitary, laterally compressed spikelets and flat or filiform rachis without joints.Majority of the taxa (ca.34 spp., 3 subspp.and one variety) are confined to Peninsular India with 26 endemics (Kiran Raj et al., 2015b).Moreover, the monotypic genus Nanooravia Kiran Raj & Sivad.belonging to the bitypic subtribe Dimeriinae, is also endemic to this region, indicating it to be the centre of diversity of the subtribe (Kiran Raj, 2008;Kiran Raj et al., 2015b).The infra-tribal classification of Andropogoneae and especially the systematic position of Dimeriinae are enigmatic and still controversial (Clayton and Renvoize, 1986;Simon, 2007) due to the lack of sufficient data from the representative taxa.
Interesting specimens of Dimeria were collected during botanical explorations in Southern Western Ghats in Karnataka, India, and detailed study showed them to be representing new taxon related to Dimeria hohenackeri.It is described herein as a new subspecies of Dimeria hohenackeri Hochst.ex Miq.The species belongs to Dimeria sect.Capillares, with distribution extending from lowland grassy slopes of Western Ghats in Maharashtra through Karnataka to Kerala in Peninsular India.Dimeria sect.Capillares is distinguished by capillary raceme-rachis with distantly arranged spikelets, and is endemic to Indian subcontinent (Kiran Raj et al., 2015b).Detailed description of the new subspecies with other relevant information including illustration is provided for easy identification of taxon in field.A key to the subspecies of D. hohenackeri in India is also provided.(Fig. 1).Diagnosis: Dimeria hohenackeri subsp.kodaguensis closely resembles subsp.hohenackeri, but differs in having mat-forming culms and branching at the extreme lower nodes, leaves crowded at culm-base, racemes 2-3 in number, spikelets 3-4 mm long and glumes not widely divergent during anthesis.
Flowering and Fruiting: October-December.
Habitat: Grassy slopes along the forest margins, alt.250-300m.Distribution and Conservation status: India, Southern Western Ghats in Karnataka.Known only from the type locality.In the absence of data on distribution and abundance, it is currently categorized as belonging to Data Deficient (DD) (IUCN, 2012;IUCN, 2014).

Etymology:
The infraspecific epithet is indicative of name of the type locality -Kodagu, in Karnataka State, India.
Notes: Dimeria hohenackeri is quite distinct from all other species of the genus by its characteristic 3-5 slender racemes, capillary rachis, distantly placed, stalked spikelets and slender awns.Dimeria hohenackeri subsp.kodaguensis mainly differs from D. hohenackeri subsp.hohenackeri in having mat-forming culms with leaves crowded at culm-base and racemes 2-3 in number.Distinguishing morphological features of the two subspecies are provided in Table 1, and a key to the subspecies of Dimeria hohenackeri is provided below.