These are called Tissue Culture Pouches. They are small zip locked bags of aquarium plants grown in a laboratory conditions and guaranteed to be free of all pesticides and bugs like snails.
Here’s another stem plant that grows into a beautiful specimen given time and the right conditions and if you want to add some colour, check this plant out. Often known by other names like Mesakana, Messancana, this colourful aquarium plant prefers soft water to flourish. Under bright light, it will produce its best colours which are quite orangey.
Plant it in the mid / back ground for best effect and watch it sway in the current.