I found this weird mossy plant growing in my pot. It has a cool shape actually. There are crater-like pits on its leaf. I really liked it and want to know its name. I live in Istanbul, Turkey.
Definitely Marchantia polymorpha, but that and the presence of moss means the soil in that container or pot or whatever it is is stagnant and waterlogged. It needs aerating by turning the soil over, preferably adding some balanced fertilizer at the same time, if you want to grow other plants in there. If you're quite happy with it growing there, and don't want to grow anything else in it other than possibly bog plants, then fine, leave it. It's quite an interesting plant in its own right.
In response to your query below, no, you shouldn't be worried exactly, but if there are other plants growing in there, you might want to check the drainage is working properly in terms of holes in the container by checking they are not blocked, gently turn over the soil to remove the liverwort and moss. If your Chestnut, Black Cypress and Pine are just small seedlings, then best not add fertilizer at this stage - presumably you will shortly be pricking out those seedling plants into separate pots anyway.