Hi, I would appreciate some advice on the following:

I have two potted lillies on a small outside terrace which have flowered already. Since flowering I have noticed that small black bud like growths have grown on the base of the top stem (where the leaf joins the stem).

Can anyone tell me what these are and whether they are part of the plant and if so what are they? If not, do I need to remove them?

I have also noticed that some of the leaves are turning yellow and black. Is this effect of Whitefly?

Thanks.

Rob B