The organelle responsible for storing starch in a plant cell is the amyloplast.

Here's a bit more about amyloplasts:

* Structure: Amyloplasts are colorless plastids, meaning they lack chlorophyll. They are essentially specialized storage compartments for starch.

* Function: Amyloplasts convert glucose (sugar) into starch for storage. This starch can be used as a source of energy by the plant, particularly when photosynthesis is not occurring, like during the night.

* Location: They are found in various plant cells, especially in roots, tubers, and seeds where starch accumulation is high.

Let me know if you have any other questions about plant cells or organelles!