REPRODUCTION IN DRAPARNALDIOPSIS INDICA BHARADWAJA

Abstract

The genus Draparnaldiopsis was established by Smith & Klyver in 1929 on the basis of the study of a single species (D. alpinus) from the U.S.A. The Indian species, i.e. D. indica, described by Prof. Bharadwaja in I933, was collected from a shallow pond at Benares in August I93I. As the Indian form differed from the American one in some respects, the diagnosis of the genus was amended to include the Indian species (cf. Bharadwaja, I933, p. 9). D. indica Bharadwaja has by now been collected from many places in the United Provinces. It has also been found growing in some parts of Assam (cf. Parukutty, 1939) and at Lonavla, Poona District.* Except for those mentioned no other species of the genus has been discovered. In recent years Draparnaldiopsis has aroused considerable interest (cf. Fritsch, I935, p. 254) on account of certain peculiarities, viz. (i) differentiation of the filamentous plant body into main axis bearing long and short laterals of unlimited and limited growth respectively; (2) differentiation of the main axis into alternately arranged long internodal and short nodal cells; (3) long laterals repeating the structure of the main axis, and the short laterals showing no evidence of an axis and being broadly orbicular owing to the spreading nature of their subulate branches that terminate in long hairs; (4) the origin of both kinds of laterals from the median portion of the nodal cells only, the long laterals to the number of one to four and the short ones in pairs or in whorls of four; (5) production of branched rhizoids from the basal cells of the main axis (generally arising as independent structures and sometimes representing modified short laterals), as well as from any part of a lateral of limited growth and only occasionally from internodal cells, sometimes forming a dense cortical covering around the main axis and the bases of the branches (Figs. I-4) (cf. Bharadwaja, 1933, Text-fig. 2 A-G; P1. VIII, figs. 2-4). This genus, perhaps, exhibits the highest differentiation of the plant body among the Chaetophorales. So far only the vegetative parts of the plant have been described and the reproduction has not been studied. It is with this that the present investigation is mainly concerned. The material collected by the writer was from a shallow pond near the village of Pahari, about four miles from the Benares Hindu University grounds, where it was growing profusely on aquatic angiosperms. In the initial stages, the habit of the plant is almost like that of a Chaetophora; later the gelatinous balls enlarge and become more diffluent. Finally, the alga presents a dark green beaded appearance owing to the formation of a large number of laterals from the nodal cells, thus simulating the habit of a