The Journal of Indian Botany/Volume 1/September 1919/The Myxophyceæ of Lahore
THE MYXOPHYCEAE OF LAHORE.
S. L. Ghose, M. Sc.,
Government College, Lahore.
Probably no other group of the vegetable kingdom has been so much neglected by morphologists as that of the Myxophycece. In India practically no work on them has been done at all. With the exception of a few stray records of certain Indian species by Schmidle, Hassal, Turner and West, absolutely nothing is known about the Indian Blue-green Algae.
At first sight, one would not think that the Blue-green Algae are found to any large extent in Lahore, but a little careful observation reveals a large variety of them, and in fair abundance. After the rains, that is in the months of October and November, they are at their best, and then again in February and March. Even in such bad months as May and June, or December and January, they are quite easily obtainable ; so that one can rightly say that the Blue-green Algae flourish fairly well in Lahore throughout the year. In this connection it might be noted that Lahore is situated in 31 35' N. and 74° 20' E. Its height is 732 feet above the sea-level. The hottest months, namely May and June, have a mean maximum temperature of about 106° F., the actual highest might go up to 120° F. The coldest months, namely December and January, have a mean minimum temperature of 40° F., the lowest never going below 29° F. Rainfall is chiefly confined to the months of July, August and September, and ranges between 8 and 25 inches.
The sources of material for examination are manifold. A large number of the Blue-green Algae are found throughout the year in places, where there is a constant flow of water, such as drains and water-courses. Artificial tanks kept constantly full of water, such as those in the Shalamar and Shahadara Gardens, also form a useful permanent source. Again, after the rains, a few natural ponds and ditches are left by the road-side in the outskirts of Lahore, which take quite a long time to dry up, and are generally found to be full of algal flora. In addition to all these, short-lived varieties are found on ordinary ground or lawns, on which rain or well-water has stood for even a short time. Another interesting source is afforded by the tree-trunks, which are sometimes covered by beautiful varieties after the rain has moistened them. SYSTEMATIC* Of the two orders of the Myxophycea, namely the Coccogoneaz and the Hormogonece, the latter has been much more studied by the writer. Amongst the former, Chroococcus turgidus Kuetz, (Cooke, 7. c. p. 204, pi. 83, fig. 2) is very commonly found for the most part of the year, generally sticking to the submerged walls or the floating masses of decaying vegetable matter in stagnant ponds or ditches. It is about 20/* thickness, and is often seen to be dividing into two, or rarely into four.
Gloeocapsa polydermatica Kuetz., is very common amongst the grass on lawns after a little rain or watering. It forms a thick, green layer when moist. Individual cells have a hyaline lamellose membrane, and are about 5/u. thick. When dry, the stratum becomes greenish-brown, the membrane of the individual cells also taking on that colour.
Clathrocystis aeruginosa Henf. (De Toni, I.e. p. 94: Cooke, I.e. p. 212 pi. 86, fig. 7) forms a bright green scum on stagnant water, generally where the water is full of waste organic matter such as the Duck Pond in the Zoo. Fronds of various sizes and of various shapes are commonly met with at the same time. Young fronds seem to be solid, but as they grow old they become hollow, and finally clathrate.
Two or three species of Merismopedia are fairly common, with their families freely floating in stagnant water, or sometimes sticking to floating masses of decaying vegetable matter.
Of the second orders Hormogoneai, the Cohort Psilonematea is very well represented in Lahore, while the Cohort Trichophorea is as yet found to be represented only by Eivularia bullata Berk. Of the former, the three families, Oscillatoriacece, Nostocacece and Scytonemacece have been found to be fairly well represented, while no plant of the Stigonemacece has as yet been discovered.
Oscillatoria princeps Vauch. (De Toni, /. c. p. 150) is the thickest species of the genus yet found. It generally occurs in dirty drains, carrying off water from road-side water-pipes. Stratum dark green, first attached to the mud and then floating. Trichomes straight, rigid, yellowish-green, about 36/* thick. See Fig. 1.
Oscillatoria tenuis Ag. (De Toni, I. c. p. 166 ; Cooke, /. c. p. 249; pi. 96, fig. 8) is the commonest Oscillatoria of Lahore, found generally in dirty draius and in places constantly wetted, such as in mud round water-pipes or wells. Stratum thin, bright green. Trichomes radiating and actively oscillating, 4-8/* thick, generally a little constricted at the joints. Two varieties occur in Lahore, one with straight broad apex, and the other with curved and a little attenu- ated apex.
Osciliatoria terebriformis Gom. (De Toni, I. c. p. 189) is generally found forming a green scum on stagnant ponds, associated with Clathrocystis csruginosa and Arthrospira Tenneri Kuetz. Trichomes free swimming, flexible, screw-shaped or in lax spiral, with unconstricted and indistinct joints, 4-6/x thick ; apex generally drawn out.
The Sub-family Spirulinecs is represented by Arthrospira Jenneri Kuetz. (De Toni, I. c. p. 206; Cooke, p. 245, pi. 96, fig. l) which, as mentioned above, is generally found associated with Clathrocystis csruginosa and Osciliatoria terebriformis. Trichomes bright green, elongated, 4-6/* thick. Spirals 10-16/* in diameter, and about 8/* distant. Joints distinctly constricted ; cells globose.
Of the Sub-family Lyngbyecs, Phormidium is more frequent than Lyngbya. Phormidium ladinianum Gom. (De Toni, l.c. p. 218) has been found on tree trunks, especially on that of Acacia modesta, associated with Phormidium Hansgirgi Schm. and Tolypothrix byssoidea Kirchn i Stratum dark green, thin, fibrous. Trichomes straight, flexible, constricted at the joints, 4-6/* thick. Sheath thin, hyaline. Contents granulose, sometimes hyaline in the centre. See Fig. 3.
Phormidium tenue Gom. (De Toni, I. c. p. 227) generally sticks to the submerged walls of artificial tanks, forming a membranous, expanded, dirty green stratum on the mud. Trichomes long, a little curved and densely intricate, slightly constricted at the joints, 1-2/* thick.
Phormidium Hansgirgi Schm. (De Toni, I. c. p. 235) is found on tree trunks, associated with Tolypothrix byssoidea and Phormidium ladinianum, forming a dark bluish-green stratum. Trichomes parallel, 10-12/* thick, with broad convex apex. Sheath hyaline when moist, and dirty brown and fragile when dry. See Fig. 4.
Phormidium Moerlianum Grun. (De Toni, I. c. p. 236) is found in stagnant water, where decaying vegetable matter is present. It is generally associated with a species of Oedogonium. Trichomes long, a little curved, brownish, 9-12/* thick ; joints very short. Sheath thin, colourless. Dissepiments granulated. See Fig. 5.
Lyngbya aestuarii Lieb. (De Toni, I. c. p. 262 ; Cooke, I. c. p. 258 pi. 101 fig. l) is commonly met with, associated with a species of Oedogonium, and forming freely floating greenish masses. Trichomes long, flexuous, blue-green, granular, about 40/* thick; joints very short. Sheath hyaline, clearly lamellose and brownish when old. The Sub-family Schizotrickea is represented by Microcoleus vaginatus Gam. (De Toni, p. 374 ; Cooke, p. 258, pi. 99, fig. 2, under M. tcrrestris Deson) which lives commonly on damp mud, such as that in lawns, flower-pots, and around ponds and ditches. Trichomes long, collected in filiform, tortuous fascicles, enclosed in a common mucous sheath, from the apes of which they come out in a penicillate manner. Dissepiments granulated, Fascicles 75-80/* thick ; trichomes 4-5/* thick.
The family Nostocacecd is represented by Nostoc commune Vauch. (De Toni, I. c. p. 404 ; Cooke, I. c. p. 231, pi. 91, figs. 4-7) and Cylindrospermum majus Kuetz. The former is found in large abundance in damp soil, even on lawns after a little rain or watering. Colonies are at first globose and resemble Botrydium, then they expand and become more or less irregular, but still keeping the outer membrane intact. Trichomes flexuous, loosely intricate ; joints spherical, uniform about 5/* thick. Heterocysts globose, 7/* thick.
Cylindrospermum majus Knetz. (De Toni, I. c. p. 424) is occasionally met with, forming a bluish-green, thin expanded stratum on damp mud. Trichomes 4-5/^ thick. Heterocysts oblong, 6-8/* thick. Spore cylindrical, 10/* wide, 20-25/* long.
From the Sub-family Scytonemacea, three species of Tolypothrix are commonly met with in Lahore. Tolypothrix distorta Euetz. (De Toni, p. 541 ; Cooke, p. 268, pi. 108, fig. 2) is very abundant in stagnant or very slowly running water, such as the broad water- courses of the Shalamar Gardens. It generally forms a very much expanded bluish -green stratum on broad floating, half -decayed leaves, such as those of the water lily. Trichomes and pseudo-branches loosely interwoven, 8-11/* thick ; joints sometimes indistinct. Sheath membranous, thin, sometimes inflated at the base of the branch, hyaline, yellowish- brown when old. Heterocysts 8-9/* thick, and 12-14/* long.
Tolypothriz byssoidea Kirchn. (De Toni, B.C. p. 551) forms a dark brownish stratum on the trunks of trees such as those of Acacia modesta, and is generally associated with Phormidlum ladmlanwm and Phormidlum Hansglrgi. Trichomes 9-11/* thick, with irregular pseudo-branches, torulose. Sheath thin, yellow or brown, fragile, tubular. Heterocysts oblong, about 16/* long.
Tolypothrix arenophila West (De Toni, I. c. p. 554) lives on damp coarse mud, such as that in lawns or around ponds and ditches. At first it forms small circular bluish-green, shiny patches, which expand later on. By coalition of several such patches a very extensive stratum is produced. Trichomos flexuous and contorted, densely intricate, about 6/* thick, with few pseudo-branches. Sheath thick, yellowish-brown, firm, lamellose when old. Contents granulose, refringent. Heterocyst oblongo-rectangular, about 10m long.
As mentioned above, of the Cohort Trichophorecs, in Lahore only Rivularia bullata Berk. (De Toni, I.e. p. 660) has been found as yet. It forms hemispherical, Iobed, gelatinous fronds on damp soil by the river-side. Trichomes 6-8/* thick, bluish-green, a little constricted at the joints, thinned out intoPa hyaline point at the apex. Heterocyst globose, 6-8/x thick. See Fig. 6.
Perennations. In this connection, a few observations might very well be recorded. Terrestrial forms, such as Gleocapsa majus, Nostoc commune, Phormidium Hansgirgi, Tolypothrix byssoidea, Toly- pothrix arenophila, generally tide over the unfavourable time by enclosing themselves in their sheaths, which often become much thicker and sometimes lamellose, and take on a yellowish-brown colour. On the return of favourable conditions they come out of the sheath, and multiply.
Resting spores have been very clearly seen in Tolypothrix distorta in all the stages of development. Generally a number of cells, about four, fuse together by the absorption of the intervening cell- walls and swell up. The contents take on a separate wall, which becomes firm and yellowish-brown. Many spores are formed in a chain-like series. They are oblong in shape, and 18-21/* by 11-13/u. in size. Germination of these spores has not been observed as yet. See Fig. 7.
CONCLUSION. The species of the Blue green Algae, described above, occur quite commonly in Lahore, but in addition to these» there are a few others, which are met with only occasionally ; and for that reason have not been yet identified or studied properly.
Explanation of Plate III.
Fig* 1. A small portion of Oscillator ia princeps. (x500).
Fig. 2. A filament of Oscillator ia terebriformis. (x 1000).
Fig. 3. A portion of Phormidium ladinianum. (x600).
Fig. 4. A portion of Phormidium Hansgirgi. (x666).
Fig. 5. A portion of Phormidium Moerlianum. ( x 666).
Fig. 6. Two filaments of Bivularia bullata. (x 1000).Fig. 7. A portion of a filament of Tolypothrix distorta, forming resting spores, (x 500).
- * The classification of the Myxophycese followed in this paper is taken from J. B. De Toni's 'Sylloge Algarum', Vol. V., (1907). The species have been identified from descriptions in that book or from descriptions and figures given in M. C. Cooke's British Fresh-water Algae (1882— 1884). Exact references are given after each species.