Crypts have a rhizome/ tuber that keeps them alive for a few months. If they get light and fertiliser and the rhizome isn't damaged, they do quite well but try not to disturb them once they have been planted. You should also check the rhizome before planting. If it is soft and black then it is rotten. If there is black on the end of the rhizome, that part is rotten and should be removed with a sharp knife before planting.
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Ambulia, Hygrophila polysperma, H. ruba/ rubra, Ludwigia sp, narrow Vallis and swordplants are usually good beginner plants.
Water Sprite can grow on the surface and if you get too many, plant them in the substrate.
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If you have trouble growing aquarium plants, you either have terrestrial plants (not true aquatics), there is insufficient light or no fertiliser.
Liquid iron based plant fertilisers can help and so can increasing light.