Pogostemon helferi is a really lovely foreground plant that is very different looking from most others. It’s got curly leaves which makes it distinguishable.
Originating from Thailand, discovered the plant and called it “dao noi” which means little star and some hobbyists still know it by this name today. It’s still found today on the verges of rivers in Thailand and like many plants spends time above and below the water line. The soil it’s found in is predominantly clay and as a result rich in iron - there’s also a lot of calcium carbonate available to this plant which is another reason why it does well in a freshwater aquarium.
Pogostemon helferi grows to approximately 10cm tall. If light is lower then it will reach up to about 15cm but under a bright light it’s even more compact 5-8cm. Most hobbyists like it to look as compact as possible.
When planting it in the aquarium make sure you remove any decaying leaves. As Pogostemon helferi has quite a few, it’s worth taking time to do this - they only rot in the aquarium anyway. When it comes to trimming this plant, you need to remove entire shoots - this helps light to still access the plant as it grows. You can replant any shoots you remove.
It’s also happy without the addition of CO2 which is quite unusual with foreground plants that are generally a bit more demanding. With CO2 and good lighting, it grows fast and stays compact. Lower lighting and no CO2 means slightly taller plants and slower growth. The addition of liquid carbon such as Neutro CO2 is beneficial and will improve plant growth.