Flower Model Project due on April 1?

okay so here's the thing; i'm in the 6th grade and my teacher told me I have to build a model of a flower.It has to be 20 cm-40 cm tall and it has to be three-dimensional,and it has to include the following parts of the flower: sepals, stem, style, anther, petals, ovary, filament, and stigma.It also has to be able to stand up on its own so it can be displayed.Please help me do this because I have no idea what materials to use and how to put them together.Any suggestons will be GREATLY appreciated :D