Without the flowering or fruiting part of the weed it is difficult to identify any weed or plant. It may be part of the Genus Arum. These plants are an invasive perennial.

Arums spread by seed and through their root system, corms, which are bulb-like. They are spread through soil movement, gardeners, and running water. Manual removal is recommended when you have just a few and you can dig up the entire plant. Be sure to place any displaced soil and all plant parts into a plastic bag and place it the trash. Remember soil movement can spread them and never allow an invasive plant to go to seed.

There is no herbicide that is effective against arum, or most any perennial that is invasive. There are other controls you may try in addition to manual removal, see Roll up your sleeves: Use multiple strategies to control invasive weeds, but persistence and patience is needed to control most all invasive plants.