Dactyloctenium scindicum

Distribution of Dactyloctenium scindicum View in CoL in India

Bor (1960) gave distribution for the species as “hotter parts of the Middle East and penetrating in Northwest India ” chiefly referring to Rajasthan and parts of Gujarat. In Maharashtra, the report of D. scindicum first appeared in Cooke (1908) in reference to Woodrow (1901) from Konkan: Ratnagiri “Rutnagiri”. However, Woodrow (1901) did not cite any specimen in his paper to trace and study. Therefore, the report does not justify the basis of occurrence. Later, the species appeared in numerous floristic accounts ( e.g. Blatter & McCann, 1935; Sharma et al., 1996; Muratkar et al., 2012; Potdar et al., 2012; Almeida, 2014; Gaikwad & Garad, 2015; Gore, 2015). After a scrupulous study of the cited specimens, and the description provided in the above mentioned literature held at BSI, BLAT and WCAS, the characteristics such as annual habit, non-gibbous culm bases, caryopsis transversely rugose or finely granular and anthers c. 0.8 mm long were revealed. Based on these it is quite evident that their specimens belonged to two different species viz. D. aristatum (with granular caryopsis and strictly coastal distribution) and D. aegyptium (with transversely rugose caryopsis and coastal as well as inland distribution). We have not found a single true D. scindicum specimen from Maharashtra during the herbarium study and fieldwork.

In Madhya Pradesh, D. scindicum had been reported by Roy (1984) and Singh et al. (2001b). The characters provided by them in the description, such as transversely rugose caryopsis and the anthers c. 0.8 mm long, are taxonomically significant in delimiting species. Thus, we conclude that the specimens are certainly D. aegyptium . We have not seen a single true specimen of D. scindicum from Madhya Pradesh in the herbaria visited.

We have examined many specimens of true D. scindicum from Gujarat at BSI, BSJO and BLAT. These specimens are mostly from northern districts (Kutch, Banaskantha, and Surendranagar).

Indo-Gangetic plains ( Rajasthan, Haryana, Uttar Pradesh, and Bihar states)

Kumar (2001) reported D. scindicum in the Flora of Haryana. However, there is no description and details of the collected specimens given. Therefore, the identification cannot be justified.

Malik (2015), while preparing a checklist of grasses ( Poaceae ) for the Saharanpur forest division, Uttar Pradesh, reported D. scindicum . The identification cannot be confirmed as he added “Identification of grasses is chiefly based on personal observation in the field and undoubtedly, there are errors in identification of grasses”. Moreover, he provided no description or cited any voucher specimens.

Singh et al. (2001a) reported D. scindicum from Bihar but did not provide a key to identify species and there is no citation of voucher specimens.

We have not found any specimen of true D. scindicum from Haryana, Uttar Pradesh, Madhya Pradesh and Bihar at (BSI, BSJO, BLAT, WCAS, BAMU).

We have examined numerous specimens of true D. scindicum from Rajasthan, the state in India representing the highest population number of this species. There, it is widely distributed and regionally one of the most abundant grasses.

The most commonly misidentified species for D. scindicum in India is D. aristatum . The latter has a strict distribution, confined to the west coast of Peninsular India and a fairly wide distribution in Rajasthan and Gujarat. The best way to segregate these two species is based on surface characters of their caryopses, which is transversely rugose and finely granular in the former and latter respectively. Liu et al. (2005) also emphasized the importance of characters of the caryopsis in segregating genera and even species in the sub-family Chloridoideae.

In India, distribution of proper D. scindicum is strictly confined to the drier northwestern states such as the northern Gujarat (Kutch, Banaskantha, and Surendranagar districts) and Rajasthan ( Stewart, 1945; Bor, 1960; Cope, 1982; Karthikeyan et al., 1989; Sharma & Purohit, 2013). However, the species seem to have also been reported from Punjab ( Stewart, 1945; Cope, 1982), but we have not seen any specimen in herbaria. Sedgwick’s collection (as indicated in Blatter & McCann, 1935) from the open dry hills in the Ahmadabad district and Pandey’s collection ( R. P. Pandey 14868 at BSJO) from the Surendranagar district, Gujarat, appear to be the southernmost distribution points of D. scindicum in India. Beyond this most southerly distribution, there is no true distributional report of this species in India. More fieldwork in the southern districts of Gujarat state is still needed, to assess the range limits of D. scindicum .