Query Form - ENVIS Assam

A report on Hydrophytes of Deepor Beel
Deepor Beel, the lone Ramsar Site in the state of Assam,
preserves a rich biodiversity of fresh water aquatic plants.
Along with the aquatic plants, some non- aquatic marshy
or amphibian plants are found in the catchments area,
making a unique eco-system around the wetland. In order
to obtain a good record of Hydrophytic wetland plants and
also to observe the seasonal changes in vegetation, a study
was undertaken by the Department of Biotechnology,
Gauhati University in association with Assam Science
st
Technology & Environment Council (ASTEC) from 1
st
December 1999 to 31 August 2000. During the field study,
observations were made on habitat, distribution patters,
ecological adaptation and other macroscopic characters
such as height, length, colour, fragrance of flowers etc. of
each and individual plant species.
Critical morphological studies were made of the plant
specimen both live and specimen kept in preservatives
and short descriptions were drawn out. The plants were
primarily identified by comparing the various characters
with available literature, particularly local flora,
monographs, Reversionary works and also with preserved
authentic identified specimens of Gauhati University
Herbarium, Kanjilal Herbarium, Shillong, Central National
Herbarium, BSI, Kolkata. Nomenclature of all these taxa
were brought up to date in accordance with the
International Code of Botanical Nomenclature.
The plants growing in aquatic water bodies/wetlands are
usually termed as hydrophytes. The growth and
development of hydrophytes vary according to their
habitats. The main variables in the water masses are
depth of water, the presence or absence of water through
out the year, intensity of light at different depth of water,
presence or absence of submerged flora and chemical
composition of the substrate. Based on Ecological
adaptations the Hydrophytic vegetation of Deepor Beel
has been classified into 7 (seven) categories with their
unique floristic elements that are found to grow both in
and around the water body (beel). These seven categories
are,
1. Free floating hydrophytes: This category of plants
are found to come in contact with water, air and
mostly fugacious. They include some species of
Angiosperms viz. Eichhornia crassipes (Mart.) Solms.
(Meteka), Leema perpusilla Torr (Sorupuni) etc, a few
Hydrophytic fern like Azolla pinnata, Salvina
Courtesy: Dept. of Biotechnology
Gauhati University
cucullata etc, algal species like Hydrodictyon
reticulatum in coenobia, fragmented parts of Chara,
Nitella and a member of slimy balls of Cyanophycean
species and Diatoms.
2. Submerged suspended Hydrophytes: These species
are rootless, submerged aquatic plants. They remain
suspended in water and are fugacious. They
commonly include Ceratophyllum demesum,
Utricularia aurea Lour, fragmented parts of Hydrilla
verticillata, species of Chara, Nittelle, Hydrodicton
reticulatum in Coenobia species of Spirogyra,
Zygnema and slimy ball of Cyanophycean members
that either remain suspended or attached to
submerged parts of most of the aquatic plants found in
the Beel.
3. Submerged anchored Hydrophytes: The entire plant
or part of the plant are in contact with soil and water
only and remain submerged throughout their life
time. The flowers of angiospermic plants are usually
borne on long peduncled inflorescence which may or
may not project above water. The plants of this
category include Blyxa aubertii Rich, Hydrilla
verticillata Royle, Nechamandra alternifolia etc. and
algal species like Chara and Nitelle.
4. Floating leaved anchored Hydrophytes: This
category of plants develop only in stagnant water. The
natural leaves of these plants floats on the water
surface and frequently form a closed canopy and
cover the surface of water in such an extent that
water does not get warmed. Fishes, snails, etc are
found to take shelter under the leaves during the
hottest period of the day. The species under this
category are Aponogeton natans, Euryale ferox
Salisb, Nelumbo nucifera Gaertn, Nymphaea nouchali
Burm, etc.
5. Floating shoot anchored Hydrophytes: These
aquatics have contact with soil, water as well as air.
They are perennials, usually grow in shallow water,
rooted in mud and spread out branches and float on
water. The main stem remains submerged wholly or
partially. The plants of this category are, Ipomoea
aquatica Forsk, Limnophylla sessiliflora (Vahl),
Polygonum glabrum Willd, Pseudoraphis brunoniana
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