1. Mat-forming perennial found in cold springs of the eastern United States
   - American watercress, Cardamine rotundifolia

Type of: watercress

• order Ictodosauria
• order Insectivora
• order Insessores
• order Isoetales
• order Isopoda
• order Isoptera
• order Isospondyli
• order Juglandales
• order Jungermanniales
• order Lagomorpha
• order Laminariales
• order Lechanorales
• order Lepidodendrales
• order Lepidoptera
• order Lichenales
• order Liliales
• order Lobata
• order Loricata
• order Lycoperdales
• order Lycopodiales
• order Lyginopteridales
• order Madreporaria
• order Mallophaga
• order Malvales
• order mantophasmatodea