along the rhachis, usually drooping at the aculeatum var. lahatum Clarke in Trans. tips; pinnae distant, alternate or suboppos­ Linn. Soc. Ser. 2, Bot.l: 509, 1880. Aspi­ ite up to 40 on each side, tapering, 12-15 dium lobatiim (Huds) Sw. Schrad Jour. 1800 (20) cm long, pinnules distant, distinctly (2); 37. 1801 Polystichum aculeatum var. stalked, not decurrent variable in shape, lohatum (Huds). Bedd. Handb. Ferns Brit, short ovatc-acuminate with a broad auricle India 297, 1883 et with Suppl. 207, 1892. 8-20 mm long 3-9 mm broad, narrowly Rhizome thick, woody, stout, young pa­ falcate-acuminate or falcate, serrate, each rts covered with small pointed scales amon­ tooth ending in a spine-like point, proximal gst which are scattered much larger ovate acroscopic pinnule scarcely longer than the dark ones. Fronds tufted, 30-90 cm, rigid rest, its proximal side rounded below, its and leathery, usually persistent, glossy green distal obtusely auricled, the two sides form­ obove, paler beneath, narrows conside­ ing an obtuse angle at the base, veins bran­ rably towards the base, pinnate or bipinn- ched free, glabrous above, clothed with ate; pinnae up to 50 on each side, pinnate small pointed scales below. Sori generally or pinnatifid, usually curved so that the arranged in a row on either side of the mid­ lips point to the apex of the blade: pinnule rib indusium thin, peltate, caducous. (Figs. sessile or subsessile, obliquely decurrent, la, 2 left). serrate, apex acute, proximal acroscopic 2. Polystichum aculeatum (L.) Roth, pinnule oT each pinna longer than the rest, Tent. FI. Germ. 3(1); 79, 1799; Alston in its proximal side straight, its distal acutley Jour. Bot. 78: 160-164, 1940; Valentine in auricled the two sides forming an acute FI. Eur. r. 20, 1964. PolypocHum aculcatum angle at the base; veins alternately Linn. Sp. PI. 1552, \153. Polypodimi loba- branched. Sori usually many, arranged in fw/n Huds. FI. Angi. 459, 1762. Aspidiuin a line on either side of the midrib of the aculeatum Sw. in Schrad Jour. f. d. Bot. pinnule; indusium peltate, brown. (Figs lb, 1800 (2J: 37, 1801 pro parte. Aspidium 2 middle and right). J. Indian bot. Soc. 51; 140 146. ON A GLOEOCOCCUS FROM PANCKGANI, MAHARASHTRA.’ By M .S. B alakrishnan , M cera B o n d r f , (n e e g o l e ) a n d S h o b h a P u r o h h ' Department of Botany, University of Poona, Poona~ l a b st r a c t A C/wY«om/.v collected from Panchgani in Maharashtra is described. In most rcspccts it agreed with G. pyriforniis Iyengar, but ditTcred from it in the lobed nature of mature thalli. Consequently, it is described as a new variety, G. pyiiforniix var. lohosus. Tiie taxonomy of the genus Glocococcu.s is briefly discussed. 1. Acceptcd for publication on April 2, 1972. The authors are grateful to Fr. Conrad Mascarenhas for the latin diagnosis of the new taxon. The second author is grateful to the University Grants Commission for the award of a Junior Research Fellowship during the tenure of which the present investigation was carried out. The alga described in the present paper mucilage. The cells are motile and cons­ was first collected from a permanent tantly show a gentle oscillatory or irregular fresh water pond in Panchgani (on the movement and at short intervals a jerky table land), on the 21st August, 1971. The forward and backward movement also. ovoid or irregular balloon like mucila­ A single pyrenoid is embedded in the ginous colonies were attached to the edges sohd, imperforate and cup-shaped chloro- of the rocks at the margin of the pond. plast (Figs 2, 3). Some colonies were also found sticking to G. minor differs from G. mucosus in the edges of the stems of submerged having smaller cells (10-13fi long), and aquatic plants and decaying twigs. The colonies which do not exceed 2-3 cm. colonies were upto 2.5 cm long and up to (a hazel n u t ) in size. Since the nature of 1.5 cm broad. the chloroplast was not specially men­ About three weeks later another coll­ tioned by Braun, Lund assumed that it ection was made from the same spot. This must have been similar to that of G. time the alga was less abundant and the mucosus (Braun 1856, Lund, 1957). size of the colonies was smaller. G. braunii has small colonies reaching Slender and more or less irregularly bran­ the size of a pea. The cells are 10-17[>i. ched or lobed colonies seemed to have long and 8-I6|a broad and a totally di­ replaced most of the ovoid balloons. fferent cell organization. The parietal There appeared to be no definite pattern chloroplast is basin shaped reaching al­ of branching or lobing and hence colonics most to the apex of the cell and is per­ exhibited a great variety of shapes. Each forate and irregularly thickened. Py- had a well developed hold fast like renoids are lacking (Lund, 1957). structure at the base (Fig. 1). In G. pyriform is the colonies are py- A large number of small and large riform and 1-3 cm. long and 0-1.5 cm cells of chlamydomonad organisation lie broad. The biflagellate cells have an irregularly scattered in the mucilaginous organization quite similar to G. mucosus matrix. The outer mucilaginous wall is (and G. minor). Iyengar however, does firm and unstratified. Most of the ceils not give cell dimensions. are concentrated at the tip or a little be­ As may be seen from the descriptions low the tip of each lobe or branch in the above, the Panchgani Gloeococcus differs colony. As a result, the tips appeared from the four known species in some way bright green while the lower portions were or the other from G. mucosus in the much very pale green or colourless. smaller cell dimensions and size of the The very young colonies, however, do colonies and their much lobed nature. not show this demarcation. The cells are Though the thallus in G. mucosus is irre­ evenly distributed all over and the colony gular, the description that it reaches the is uniformly coloured. size of an apple would appear to indicate a The cells are 8 to 15|a long and 7 to sub-globose, rather than a lobed nature. 12(ji broad. The smaller cells are ovoid From G. hraunii it differs markedly in cell and they become globose as they enlarge: organisation. Thus the largest cells in a colony are more All these characters showed that the or less spherical and about I4[x in dia­ Panchgani alga was a species of the rare meter. Each cell has two distinct and equal and interesting volvocalean genus Glo- flagella, not projecting outside the investing eococcus Braun, first described by A. Braun (1851) as an epiphyte on another alga These cells constantly showed slight in Freiburg in Germany. According to oscillatory and also short forward and Braun the alga formed sub-globular gelati­ backward movements within the mucilage. nous colonies reaching, in one species, the Braun established two species—G. size of an apple. All the cells of the mucosus Braun (the type) and G. minor colonies possessed a pair of flagella which Braun. Subsequent to Braun's original disappeared only at the time of division. report, the alga was not seen again for colony and lobing. over a century. In 1957 J.W.G. Lund and cell organisation our alga differs mar­ described a third species, C. braunii Lund, kedly from both these species in the much from a pond at Ambleside in England. A lobed nature of the mature thallus, though few years later Iyengar (1961) described the young colonies are simple and ovoid another species from India, viz.; G. pyri- to clavate, very similar to those of G. py- fo rm is Iyengar. riformis. Iyengar does not give cell di­ Since Iyengar’s report, this genus does mensions for G. pyriformis'. but the writers not appear to have been recorded again feel that these could be similar to those M- Bondre del. FiciS. 2-3. Glocococcuspyriformis s'dx. lohosiis. Fig. 2 pari of a vesicle showing? the outer limit of the mucilaginous envelope and arrangement of cells within the envelope. Fig, 3. Individual cells enlarged to show details of cell organization. from India or else-where so far. ofPanchgani Gloeococcus. As such they are According to Braun (1851) G. mucosus inclined to consider the Panchgani alga as iias generally large cells (17-20[x long) G. pyriformis. On account of markedly iind the colonies reach the size of an apple. lobed nature of the mature thallus, how­ The chloroplast is imperforate and cup- ever, they feel that it should be considered haped, and the single pyrenoid is in the as a distinct variety viz; G. pyriform is '^asal part of the cup. var lobosus. However, while resembling G. minor G. pyriformis Var. lobosus var. nov.— <;nd G. pyriform is in size of the colony Colonies irregular in shape, sub-micro­ scopic to 2.5 cm long, up to 1.5 cm. in Fritsch(ln West and Fritsch, 1927) kept the diameter, ovoid sub-clavafe when young, two genera distinct. Lund (1952) at first irregularly lobed in the adult condition. agreed with Wille but later kept the two Cells ovoid when young, later becoming genera separate (Lund, 1957). though he globose, irregularly distributed in the considered Braun’s Gloeococcus a “ genus mucilaginous matrix, closer together in the of doubtful validity.” In Iyengar’s opi­ upper portion than in other parts of the nion (I960, p.
Details
-
File Typepdf
-
Upload Time-
-
Content LanguagesEnglish
-
Upload UserAnonymous/Not logged-in
-
File Pages7 Page
-
File Size-