With out clarity in the specimen ( inflorescence, flowers and fruits) it is difficult to identiy the material. But based on the leaf shape and colour of the leaf, I think it may be Avincennia marina

Avicennia marina is less rounded at the ends and the leaves are generally smaller. Where were the leaves collected from?

Hai Geddada and Nasreen

The leaves were collected at south region of java, Indonesia

It inhabits riverine mangrove ecosystem with very low salinity about 1-8 ppm

Actually it looks like xylocarphum granatum but not quite sure since there was no fruit or flower sample

I  believe it may not Xylocarpus granatum and may be either A.marina or A.officinalis, Further,n Xylocarpus may not survive such a low saline zones. Thank you

Since he said that the leave are compound, it is not  a species of Avicennia. Meliaceae family do have compound leaf and the plant may be Xylocarpus granatum. 

To me it looks more like Xylocarpus. A. marina is very common in our mangroves and quite different from the leaves in the picture in terms of size, colour and shape. However, the size may not be right for X. granatum either. Perhaps consider the genus Ceriops? I am not sure what size the leaves reach or if Ceriops is tolerant to low salinities but the shape and leaf arrangement could be correct.

Well both C. tagal and decandra generally have smaller leaf compare to Xylocarpus granatum.1-10 x 2-3,5 cm, 3-10 x 1-4,5 cm, and 4,5 - 17 cm x 2,5 - 9 cm, respectively.

(source : http://wetlands.or.id/mangrove/mangrove_species.php?id=44)

In addition, i can only found one tree of this species among the others like Rhizopora mucronata, Avicennia alba, Sonneratia alba which were abundant

Any idea?

Identification of mangrove species just based on one twig sample is highly difficult. Lot depends on the inflorescence , fruits as well as the root system. Genus Xylocarpus and Avicennia can be easily differentiated by their difference in root systems.

Hi Akbar, Its most likely either xylocarpus or ceriops, as both have rounded compound leaves. The leaflets of xylocarpus are in the same plane, while in ceriops they are whorled. In the picture you have, the specimen seems to be flattened ( like in a herbarium), and the leaflets appear whorled, so perhaps its ceriops tagal ( not sure of the species, although C.tagal is found all over the indo-pacific). Its not sonneratia as sonneratia has simple leaves. Its certainly not avicennia marina as A. marina has pointed leaves. also,from the perspective of mangrove zonation,  xylocarpus and ceriops are both found in lower salinity environments while avicennia, rhizophora and sonneratia can withstand full marine salinity ( 35 ppt).  The issue is tolerance to high salinity and not low salinity, all mangroves can be grown in freshwater, however mangroves have evolved several salt-tolerance or salt-exclusion mechanisms to be able to colonize areas with saline water. While they can grow in freshwater, they get out-competed by other plants in fresh groundwater regions.  The attached pub has some info on mangroves of East Africa, with references to another guide from SE Asia. 

Technical Report A Rapid Ecohydrological Assessment of the Ruvu River Estuary, Tanzania

Looking at the pictures the leaves do not look as if they were compound, but rather like simple leaves directly attached to a woody twig (with visible stipule-scars). Also, to me, it does not generally resemble to Xylocarpus. These leaves here are shiny-green above and lighter below, floppy-leathery, opposite but unevenly spaced, and the petiole is flat above. The twigs appear to be square-shaped, with many leaf-scars, and ring-shaped joints or swollen nodes. My suggestion here is to have a look at: Avicennia officinalis. This would also fit nicely with the habitat (see http://tidechaser.blogspot.ch/2011/11/api-api-ludat-avicennia-officinalis.html; it has even been found at 50 m elevation inland, see http://www.hort.purdue.edu/newcrop/duke_energy/Avicennia_officinalis.html#Distribution

 See comment by Paromita (more info would help) but you may work from there. b R

I also agree with Roland Cochard; first ascertain the sample for simple or compound leaves by just checking the position of auxillary buds. Also refer the link for Avicennia officinalis in http://amap-collaboratif.cirad.fr/pages_logiciels/Mangrove_web/especes/a/aviof/aviof.html

here attached additional photo of our speciment, please shed some light on us

regards 

Dear Akbar

Leaves are not compound, these are the simple leaves, besides numerous pneumatophores are present around the plant trunk. It is a  clear  indication for the Avicennia. And it is not Xylocarpus because there is no buttressed stem which is the charactersitic feature of the Xylocarpus. Thank you 

In your new pictures the pic of the leaf from above seems to show salt specs exuded at the surface of the leaf, whereas from below there is no such thing. That seems to be another indication for Avicennia officinalis: "Unlike the other native Avicennia species, the salt glands are on the topsides of the leaves. They excrete part of the remaining quantity of salt which was not excluded at the roots." See text http://tidechaser.blogspot.ch/2011/11/api-api-ludat-avicennia-officinalis.html , and also have a look at pic no 4 there; the leaves look very much like the ones you have. I am pretty sure it is Avicennia officinalis.

Sirely the leaves are not compound, so surely not Xylocarpus.  The yellow flowers and the salt exudation on leaves is a clear indication of  Avicenia. It is surely Avicenia.

Thanks for the anwers, so is it a simple leave? Could someone correct me about this picture

a. stem/trunk

b. petiole

c. petiolule

d. bud 

anyway, how about the size of leaf? since average length of our sample leaf exceed length range of common A. officinalis? (more than 11 cm)

Regards

Dear Akbar

First i woulk like to give some clarification regarding the stem and trunk. The trunk is the main structure of the tree that supports the whole Plant.  A stem of a plant is one of the two main structural axes of a vascular plant. The stem can be divided into two parts; node and internodes. So numerous pnuematophores are present around the trunk not around the stem. Nodes produce the leaves and here leaves are opposite with a petile. Coming to the Photograph

A) is stem 

B) also stem 

C) Petiole

D) Axillary bud which developed into a lateral branch

And on the basis of the flower colour we can't decide the species because, In  A. officinalis , A. marina and A. alba floweres are orange yellow to yellow colour. So based on the bark colour and size of the leaf and colour of the leaf we can differenciate the species. In A. marina leaves are more than 11 cm with pointed apex and colour  siver grey. So you please check 

Thank you

Regarding leaf size there are different indications, e.g. up to 12 cm: https://www.hort.purdue.edu/newcrop/duke_energy/Avicennia_officinalis.html , but leaves often exceed the size given in the literature, especially if the leaves were 'shade leaves' which generally grow larger than leaves exposed to much sun. Cf. comment by Mr. Rao. The leaves are attached to woody twigs. You may google images of Avicennia leaves, and for 'bud scar', and compare to your sample.

Thank you for all of explanation, now im pretty sure it is Avicennia officinalis from its leaf shape and type, root type, and salt glands :)

Regards

Akbar