BRYOPHYTE FLORA OF GREATER MYMENSINGH DISTRICT OF BANGLADESH-CLASS : BRYOPSIDA

The Greater Mymensingh District, particularly the hilly areas are rich in bryophyte flora. The present paper on Bryopsida is based upon primary as well as secondary data collection and includes an account of 51 species under 35 genera, 21 families and nine orders. A short description of each species with locations, dates of collections and name of collectors are provided. Introduction A reasonably good amount of works have been done on mosses of Bangladesh (Banu 1991, Khatun 2002 and references therein). However, our knowledge on districts or zonal distribution is very scanty. Tixier (1967) collected and reported many mosses from Chittagong and Cox’s Bazar of Bangladesh, but none from Greater Mymensingh District, which currently includes six administrative districts, namely Jamalpur, Kishoreganj, Mymensingh, Netrokona, Sherpur and Tangail. Banu (1991) for the first time gave a district-wise distribution of mosses, but her work was confined only to Acrocarpous mosses. Banu-Fattah (1998) dealt with bryophytic flora of Chittagong Zone where a number of hepatics and mosses were reported, but the areas covered were limited to a few sites only. So we do not have a complete record of bryophytes as a whole from any district or zone. In the present paper, an attempt has been made for the first time to prepare a comprehensive list of mosses under the class Bryopsida of the Greater Mymensingh District. Here the authors have covered many localities of the present administrative districts of Greater Mymensingh by collecting a large number of bryophytes including mosses. All the previous reports on Bryopsida from the Mymensingh region which have been published so far were also consulted while preparing the list. Materials and Methods The areas covered in this study constitute the Greater Mymensingh District (latitude 24°05′ and 25°36′ and longitude 89°70′ and 91°20′) of Dhaka Division of Bangladesh which at present includes six administrative districts. This area is on the centre of the Corresponding author. Present address: C/o Prof. Quazi Abdul Fattah, Department of Botany, University of Dhaka, Dhaka 1000, Bangladesh. E-mail: botany@univdhaka.edu 48 BANU-FATTAH AND SARKER northern side of Bangladesh. Northern part of this zone have hills and hillocks which is an extension of Garo Hills of Himalayan-Hindukush mountain range of India, the other part of this region is mostly low-lying plains. Some part of this region is above 10 m and the rest is about 3 m above sea level. The land is intersected with a large number of rivers, streams and canals of which the River Brahmaputra is the most important one. Temperature of this zone usually ranges from 11.6°C in January to 32.7°C in July. Annual rainfall is moderate, being 232 cm and humidity varies from 62-95%. The central part and also some scattered strips of this zone have natural forests. This report is mainly based upon fresh materials collected from different localities under the Greater Mymensingh District area. Most of the bryophytes collected were worked out and identified and all the specimens collected are preserved in the Bryology Herbarium, Department of Botany, Govt. Ananda Mohan College, Mymensingh. In addition, the occurrence of many species is based on previously published documents. Banu-Fattah and Hadiuzzaman in a series of publications (1994, 1995, 1996a,b,c, 1998a,b,c, 2003a,b, 2004, 2006a,b) on the Acrocarpous mosses of Bangladesh described several species from the families Polytrichaceae, Ditrichaceae, Dicranaceae, Leucobryaceae, Calymperaceae, Fissidentaceae, Pottiaceae, Funariaceae, Splachnaceae, Bryaceae and Bartramiaceae from the studied region. Khatun (2002) reported many Pleurocarpous mosses from this region, but only those mosses are included here which have been published so far (Khatun and Hadiuzzaman 1994, 1995, 2003, 2004, 2005, 2006, 2007a,b). The specimens used by Banu (1991) and Khatun (2002) are preserved in the Bryology Herbarium, Department of Botany, University of Dhaka (DUBH). The classification followed in this enumeration is that of the system used by Gangulee (1969-1980). A short description of each species with habitats, locations, dates and collector’s name(s) are provided. Basionyms are also provided where appropriate/available. Results The present study comprises an account of 51 species under 35 genera, 21 families and nine orders. Although this study is not very extensive, it shows that the Greater Mymensingh District is a good abode of mosses, particularly, the Acrocarpous mosses (Banu 1991). Hadiuzzaman (1984) for the first time described Calymperes tenerum Hedw. from Tangail of the Greater Mymensingh. Over the years, a number of interesting findings have been attained regarding the occurrence of mosses in Greater Mymensingh. For example, Banu-Fattah and Hadiuzzaman (1997) described a new species Splachnobryum schofieldii Banu-Fattah et Syed from Tangail. Later on, Banu-Fattah and Lal (1998) reported the occurrence of a very rare monotypic moss, Pleuridiella colei Robinson, previously thought to be endemic in India, collected from Kishoreganj, Mymensingh and BRYOPHYTE FLORA OF GREATER MYMENSINGH DISTRICT 49 Tangail Districts. Moreover, the three most common mosses of Bangladesh, namely, Semibarbula orientalis (Web.) Wijk. & Marg., Hyophila involuta (Hook.) Jaeg. and Bryum apiculatum Schwaegr. are also very common in this region (Banu-Fattah and Hadiuzzaman 1993). Recently, Funaria hygrometrica Hedw., a well-known moss of the world, was collected only from Tangail District (Banu-Fattah 2005). It has been observed that the mosses are adapted to a wide range of habitats, but most of the Acrocarpous mosses are either terrestrial or lithophytes prefering shady, moist places of the plains or slope of hills. Most of the Pleurocarpous mosses and the species of the families Leucobryaceae and Calymperaceae of Acrocarpous mosses are epiphytes. Some species, specially, Trematodon longicollis Michx., are common in Mymensingh and grow by the sides of rivers and ponds. Robinson (1964) reported many mosses from Assam region of India, adjacent to this area, and those mosses along with many others are expected to be present here. An extensive and intensive collection will surely add more names to the moss flora of Greater Mymensingh District. More studies are needed to complete the zonal or districtwise distribution of the mosses of this region. A brief account with relevant information on all the 51 species found in the region is given in the following section. Taxonomic enumeration Class : Bryopsida; Order : Polytrichales; Family : Polytrichaceae Genus : Pogonatum Palisot de Beauvois, in Mag. Enc. 5: 329 (1804). 1. Pogonatum flexicaule Mitt., in Musc. Ind. Or. 152 (1859). Plants long, slender, dark-green; lamellae numerous covering almost entire ventral surface, 2-3 celled high at costa; sharply dentate margin; costa spinose-papillose on back, ending in an apicule. Grows on sandy soil, slope of hills and waterfall. Specimens examined: Jamalpur: Lawachapra, on slope of hill, S.K. Sarker, 2.2.1999; Mymensingh: Haluaghat, on slope of hill, Almas Uddin Hawlader, 30.9.1988. 2. P. hexagonum Mitt., in Musc. Ind. Or. 151 (1859). Plants dioicous, sturdy, medium-sized, reddish; lamellae numerous, covering almost entire ventral surface; costa promiment, percurrent, spinose; capsule hexagonal; peristome teeth 32; calyptra felty. Grows on sandy soil. Specimen examined: Mymensingh: Panihata, Haluaghat, Almas Uddin Hawlader, 26.12.1988. 50 BANU-FATTAH AND SARKER Order : Dicranales; Family : Ditrichaceae Genus : Garckea C. Muell., Bot. Zeit. 3: 865 (1845) 3. Garckea phascoides (Hook.) C. Muell., Bot. Zeit. 3: 865 (1845). Dicranum phascoides Hook., Misc. Bot. 1: 39 (1829). Plants dioicous; yellowish-green; stem long with sparse leaves all along but crowded in comal tuft at tips; sporophyte hidden within perichaetial leaves; seta very short with vaginula; peristome teeth 16, papillose; calyptra scabrous. Grows on dry damp soil, commonly found in hilly areas. Specimens examined: Jamalpur: Lawachapra, S.K. Sarker, 25.1.1993; Mymensingh: Haluaghat, S.K. Sarker, 3.2.1988; Sherpur: Zhinaigati, Gazni, Ainul Haque and Abu Bakar Siddique, 5.1.1988; near Sherpur Town, Ainul Haque and Abu Bakar Siddique, 20.1.1988; Rungtia Reserve Forest, Almas Uddin Hawlader, 13.12.1988; Tangail: Rasulpur, Modhupur Forest, Almas Uddin Hawlader, 4.11.1987 and 13.1.1988; Ainul Haque and Abu Bakar Siddique, 10.1.1988. Genus : Ditrichum Hamp., Flora 50: 18 (1867). 4. Ditrichum difficile (Dub.) Fleisch., Musci Fl. Buitenzorg. 1: 300.50 (1900-1902). Plants yellowish-green, up to 1 cm high; leaves falcate with broad, ovate sheathing base and abruptly narrowing flexuose, canaliculated subula; laminal cells rectangular to linear, vermicular; leaf margin bistratose in upper part. Grows on sandy soil. Specimen examined: Sherpur: near Sherpur Town, Almas Uddin Hawlader, 16.2.1990. Genus : Pleuridiella Robinson, J. Hattori Bot. Lab. 27: 125 (1964). 5. Pleuridiella colei Robinson, J. Hattori Bot. Lab. 27: 125 (1964). Plants paroicous, very small, 2.5-4.5 mm with leaves; leaf margin narrowly revolute, serrulate all along, cells highly mamillose; capsule immersed, spherical, cleistocarpic; peristome teeth, annulus, operculum absent. Grows on damp soil. Specimens examined: Kishoreganj: near Kishoreganj Town, Md. Abul Hassan, 7.2.1987; Mymensingh: Womens’ T.T. College, K.B. Fattah, 2.2.1987 and 5.11.1996; by the side of Brahmaputra River, near Circuit House, K.B. Fattah and S.K. Sarker, 5.11.1996: NAPE campus, K.B. Fattah and S.K. Sarker, 5.11.1996; Tangail: near Tangail Town, Md. Kamruzzaman, 14.2.1988. BRYOPHYTE FLORA OF GREATER MYMENSINGH DISTRICT 51 Family : Dicranaceae Genus: Dicranella (C. Muell.) Schimp., Caroll. Bry. Eur.: 13 (1856). Aongstroemia C. Muell., Syn. 1: 430 (1848). 6. Dicranella amplexans (Mitt.) Jaeg., Ber. S. Gall. Naturw. Ges. 1870-71: 376 (1872). Leptotrichum amplexans Mitt., in 


Introduction
A reasonably good amount of works have been done on mosses of Bangladesh (Banu 1991, Khatun 2002 andreferences therein).However, our knowledge on districts or zonal distribution is very scanty.Tixier (1967) collected and reported many mosses from Chittagong and Cox's Bazar of Bangladesh, but none from Greater Mymensingh District, which currently includes six administrative districts, namely Jamalpur, Kishoreganj, Mymensingh, Netrokona, Sherpur and Tangail. Banu (1991) for the first time gave a district-wise distribution of mosses, but her work was confined only to Acrocarpous mosses.Banu-Fattah (1998) dealt with bryophytic flora of Chittagong Zone where a number of hepatics and mosses were reported, but the areas covered were limited to a few sites only.So we do not have a complete record of bryophytes as a whole from any district or zone.
In the present paper, an attempt has been made for the first time to prepare a comprehensive list of mosses under the class Bryopsida of the Greater Mymensingh District.Here the authors have covered many localities of the present administrative districts of Greater Mymensingh by collecting a large number of bryophytes including mosses.All the previous reports on Bryopsida from the Mymensingh region which have been published so far were also consulted while preparing the list.

Materials and Methods
The areas covered in this study constitute the Greater Mymensingh District (latitude 24°05′ and 25°36′ and longitude 89°70′ and 91°20′) of Dhaka Division of Bangladesh which at present includes six administrative districts.This area is on the centre of the northern side of Bangladesh.Northern part of this zone have hills and hillocks which is an extension of Garo Hills of Himalayan-Hindukush mountain range of India, the other part of this region is mostly low-lying plains.Some part of this region is above 10 m and the rest is about 3 m above sea level.The land is intersected with a large number of rivers, streams and canals of which the River Brahmaputra is the most important one.Temperature of this zone usually ranges from 11.6°C in January to 32.7°C in July.Annual rainfall is moderate, being 232 cm and humidity varies from 62-95%.The central part and also some scattered strips of this zone have natural forests.This report is mainly based upon fresh materials collected from different localities under the Greater Mymensingh District area.Most of the bryophytes collected were worked out and identified and all the specimens collected are preserved in the Bryology Herbarium, Department of Botany, Govt.Ananda Mohan College, Mymensingh.In addition, the occurrence of many species is based on previously published documents.Banu-Fattah and Hadiuzzaman in a series of publications (1994, 1995, 1996a,b,c, 1998a,b,c, 2003a,b, 2004, 2006a,b) on the Acrocarpous mosses of Bangladesh described several species from the families Polytrichaceae, Ditrichaceae, Dicranaceae, Leucobryaceae, Calymperaceae, Fissidentaceae, Pottiaceae, Funariaceae, Splachnaceae, Bryaceae and Bartramiaceae from the studied region.Khatun (2002) reported many Pleurocarpous mosses from this region, but only those mosses are included here which have been published so far (Khatun and Hadiuzzaman 1994, 1995, 2003, 2004, 2005, 2006, 2007a,b).The specimens used by Banu (1991) and Khatun (2002) are preserved in the Bryology Herbarium, Department of Botany, University of Dhaka (DUBH).
The classification followed in this enumeration is that of the system used by Gangulee (1969Gangulee ( -1980)).A short description of each species with habitats, locations, dates and collector's name(s) are provided.Basionyms are also provided where appropriate/available.

Results
The present study comprises an account of 51 species under 35 genera, 21 families and nine orders.Although this study is not very extensive, it shows that the Greater Mymensingh District is a good abode of mosses, particularly, the Acrocarpous mosses (Banu 1991).Hadiuzzaman (1984) for the first time described Calymperes tenerum Hedw.from Tangail of the Greater Mymensingh.Over the years, a number of interesting findings have been attained regarding the occurrence of mosses in Greater Mymensingh.For example, Banu-Fattah and Hadiuzzaman (1997) described a new species Splachnobryum schofieldii Banu-Fattah et Syed from Tangail.Later on, Banu-Fattah and Lal (1998) reported the occurrence of a very rare monotypic moss, Pleuridiella colei Robinson, previously thought to be endemic in India, collected from Kishoreganj, Mymensingh and Tangail Districts.Moreover, the three most common mosses of Bangladesh, namely, Semibarbula orientalis (Web.)Wijk.& Marg., Hyophila involuta (Hook.)Jaeg.and Bryum apiculatum Schwaegr.are also very common in this region (Banu-Fattah and Hadiuzzaman 1993).Recently, Funaria hygrometrica Hedw., a well-known moss of the world, was collected only from Tangail District (Banu-Fattah 2005).
It has been observed that the mosses are adapted to a wide range of habitats, but most of the Acrocarpous mosses are either terrestrial or lithophytes prefering shady, moist places of the plains or slope of hills.Most of the Pleurocarpous mosses and the species of the families Leucobryaceae and Calymperaceae of Acrocarpous mosses are epiphytes.Some species, specially, Trematodon longicollis Michx., are common in Mymensingh and grow by the sides of rivers and ponds.Robinson (1964) reported many mosses from Assam region of India, adjacent to this area, and those mosses along with many others are expected to be present here.An extensive and intensive collection will surely add more names to the moss flora of Greater Mymensingh District.More studies are needed to complete the zonal or districtwise distribution of the mosses of this region.
A brief account with relevant information on all the 51 species found in the region is given in the following section.

Pogonatum flexicaule
Plants long, slender, dark-green; lamellae numerous covering almost entire ventral surface, 2-3 celled high at costa; sharply dentate margin; costa spinose-papillose on back, ending in an apicule.Grows on sandy soil, slope of hills and waterfall.
Plants yellowish-green, up to 1 cm high; leaves falcate with broad, ovate sheathing base and abruptly narrowing flexuose, canaliculated subula; laminal cells rectangular to linear, vermicular; leaf margin bistratose in upper part.Grows on sandy soil.
Plants autoicous; in dense cushion; leaves whitish-green, flat, thick, lingulate, loosely attached to stem, chlorocysts 3-sided; costa broad, occupying half of leaf base and entire blade; peristome teeth in eight pairs; operculum conic-rostrate; spores finely papillose; new plants grow from apex of leaves.Grows on bark of trees.
Plants densely tufted; leaves strongly inrolled and curled when dry, oblong-lingulate to spathulate, apex obtuse to rounded; costa strong percurrent; upper laminal cells multipapillose; gemmae abundant at the axil of leaves.Grows on old, damp bricks.
Plants dioicous; in dense tufts; leaf margin denticulate at apex, strongly involute when dry; costa strong, red-brown; capsule long, cylindrical; peristome absent; calyptra spirally twisted, cucullate; spores smooth; multicellular gemmae abundant on branched filaments at the axil of leaves.Very common species.Grows mostly on damp, old, concrete walls, drains, bricks and stones.

Barbula marginatula
Plants dioicous; densely tufted, yellowish-green; leaves with a very distinct hyaline margin of 2-3 rows of elongated papillose cells; costa strong; middle and upper laminal cells incrassate, densely papillose.Grows on sandy soil and walls.

Gymnostomum vernicosum
Plants in dense compact tuft or loose and scattered, small, delicate; leaves lax and distant below, crowded at apex, upper leaves broad, obovate with rounded apex; margin very rough above; costa extends up to 2/3 of leaf; laminal cells thin, upper cells multipapillose; gemmae present at the axil of leaves.Grows on damp walls, bricks, and drains.
Plants dioicous; robust, densely tufted, shoot long with whorl of innovations; stem tomentose; leaves with broader base, long acuminate apex and serrate margin; capsule sub-globose to ovoid; slightly asymmetric, mouth small.Grows on soil, usually in hills.

Hypnum hastatum
Plants dioicous; dense, forming mats, very slender, soft, bright green above, loosely attached to the substratum; stem highly radiculose; leaves lax, thin, lingulate with blunt, obtuse apex; costa ending much below apex.Grows on damp brick walls, drains and on nearby soil.