The stage in which a plant produces spores is called the sporophyte stage.

Here's a breakdown:

* Sporophyte: This is the diploid (having two sets of chromosomes) generation of a plant's life cycle.

* Spores: These are single-celled reproductive units that are dispersed to develop into the next generation.

* Gametophyte: The haploid (having one set of chromosomes) generation that produces gametes (sex cells).

Here's a simple explanation:

1. Sporophyte produces spores through meiosis (cell division that reduces the number of chromosomes).

2. Spores develop into gametophytes.

3. Gametophytes produce gametes (sperm and egg).

4. Gametes fuse to form a zygote, which develops into a new sporophyte.

This cycle repeats, with the sporophyte generation alternating with the gametophyte generation.