Ceriops decandra ( Goran )

Ceriops decandra are small trees or shrubs with coppice like growth of the inner mangrove zone and grow apparently on better drained soils. It grows as an under-story in the central south western part of the sundarbans and  typically is an associate of the species of  Xylocarpus, Excoecaria, Heritiera  and of Bruguiera. The leaves of C. decandra are rounded, having obovate tendencies and a shiny green upper surface.

The flowers are white in colour, bisexual and cluster on short stalks. It blooms in March to April. The fruit which is about  2.5 cm. long, ripens in May to July, produces a slender, clearly ribbed hypocotyl of about 15 cm. in length. The hypocotyl is broadended at the lower end and tapering upward. The bark is pale yellowish grey to dark brown in colour and contains a great deal of colouring matter. The species possesses stilt roots which develop into broad plank-like buttresses. Groan is a sours of fuellwood with high calorific value, and a source of quality honey as well.

Avicennia officinalis (Baen)

A large evergreen tree ( 15 to 20 meter tall ) of the mangrove of sundarbans grows along the river banks or depressions inside the forests.Mature A. officinalis often forms an extensive bushy growth with a partial hollow trunk. In sundarbans it often occurs in the inland depression. The leavs are obovate or broadly elliptic with a  destinctive rounded apex. The leaves are dark-green in colour but the under surface is greenish yellow.....

Orange-yellow flower ( 10 to 12 mm. in diameter )  appear from March to June and the fruits ripen from July to August. The fruit is compressed, somewhat heart-shaped,ovoid, 2 to 3 cm. long, one-seeded  capsule. The seeds germinate immediately they fall, or even on the tree. Fallen mature seeds drift with ebb and tide. The bark is smooth, dark brown or grey in colour and lenticellate. The wood is brittle and used as fuel. Its lateral roots spread in all direction through the mud send up outstanding finger like pneumatophores.

Sonneratia apetala.(Keora)

It is a common tree of sundarbans growing upto 15 to 20 meters high, appearing on newly formed land and gradually dying out on the higher ground. the species is found only in the mangroves of the coasts of Indian Subcontinent and Myanmar. The tree has no buttress and produce numerous upright, slender and sharp pneumatophores from superior roots. The bark is black in colour and with lenticels.

The leaves, average 10 to 13 cm . longs are simple, opposite, entire,leathery, narrow, lanceolate and light green in colour. Comparatively smaller flowers appear in April to June, possess 4 calyx lobes and have no petals. Ripe fruits which are green and rounded (2 by 2 cm) available from mid June to September. Seeds are buoyant and scattered by tidal water. Germination epigeal. The wood of S. apetala is light and used mainly for making planks and fuelwood. The leavs and fruits are very much preferred by deer. The ripe fruites, being sour, are consumed by the local people as chutney.

Excoecaria agallocha (Gewa)

Excoecaria agallocha grows in the drier and harder sandy mud near the terrestrial fringes of mangrove vegetation. The plant is 10-15 meter high with white latex which is irritating to the eyes and skin.
Leaves alternate,simple,obovate,leaf-margin distantly toothed,upto 9 cm. Wide. They are green in colour when young but becoming red and yellow tinted when mature. A distinctive pair of circular glands marks the point where the leaf blade joins the petiole.

The tree is easily recognized by the catkin like inflorescence. Minute yellowish-green unisexual flowers appear in May to July and the fruits ripen in August and September. The fruit is a 3-lobed capsule,rounded,smooth and 1.5 cm. in diameter. Germination epigeal. The bark is grey .  Wood is soft , whitish and used  for fuel and as raw materials for Newsprint paper mills and Match factories. The plants lack aerial root-structures and hence do not  exhibit true mangrove character..

Heritiera fomes (Sundri).

The Species Heritiera fomes is the characteristic of the forest of sundarbans and the frost is said to get its name from this tree ( Sundri ).

H. fomes is an evergreen tree with buttressed stem and grey longitudinally cracked bark with an average height  of 15 to 20  meters and diameter at breast height is 1 meter or less.It grows well in the north-eastern part of sundarban, where salinity is low and lebel of ground is intermediate. The species is a moderate light-demander,enduring more shade in youth than it does later. It produces prominent pneumatohores.

The leaves are simple, shortly petiolate, dark green on top while lower leaf surface silvery white. Mature leaf  15 to 20  cm. Long and  5 to 7  cm wide.



The flowers are simple, unisexual yellow orange in colour and organized in panicles. H. fomes flowers in March to April. The fruit carpel ripens in July-August. Individual fruit is  5 to 7  cm. Long and possesses a ridge on the outer edge. Germination hypogeal and takes  place very soon after the fruits fall. Wood of  H. fomes is very hard, weighty, durable and used for many purposes, specially for constructing culverts and making electric poles etc.

 

Acrostichum aureum

Acrostichum aureum is the gregarious mangrove fern of Sundarbans and other mangroves fern of Sundarbans and other mangroves of Asian tropics.It grows on river or creek bank where a fresh water influence is prominent. A.aureum  provides a suitable hiding place for famous carnivorous Royal Bengal Tiger of sundarbans forest and so it is named as' tiger  fern '

The fronds of A. aureum are long and leaflets are oblong and blunt,showing a distinctive red colour  when young.