Plant weight included with all bunched plants.
Stem plants are usually cuttings of plants that generally don't come with roots; this is how stem plants are sold in the aquatic plant industry. Although at times my stem plants may come with roots because I have been growing them out. All stem plants come with a plant weight that holds the plant in place and is safe for your tank.
To plant, just let the weight lay on your substrate, and the stems will grow roots throughout your substrate. You can also plant the tips, about 1/4" in your substrate if you prefer.
Please go here for more information on planting.