Question

What is the most invasive species plant in New England?

Answer 1

I couldn't find the most invasive, but found a list of invasive ones and their alternatives:

Explanation:

• Norway maple (Acer platanoides)
• Autumn olive (Elaeagnus umbellata)
• Multiflora rose (Rosa multiflora)
• Glossy buckthorn (Frangula alnus)
• Burning bush (Euonymus alatus)
• Blunt-leaved privet (Ligustrum obtusifolium)
• Yellow flag iris (Iris pseudacorus)
• Shrub-like honeysuckle (Lonicera morrowii, L. x bella,
  L. maackii, and L. tatarica)
• Bishop’s weed or gout weed (Aegopodium podagraria)
• Oriental bittersweet (Celatrus orbiculatus)

Native alternatives to plant:
- Red maple (Acer rubrum) replaces Norway maple
- Bayberry (Morella spp.) replaces autumn olive
- Climbing prairie rose (Rosa setigera) replaces multiflora rose
- Alternate-leaved dogwood (Swida [Cornus] alternifolia)
replaces glossy buckthorn
- Highbush blueberry (Vaccinium corymbosum) replaces burning bush
- Inkberry holly (Ilex glabra) replaces blunt-leaved privet
- Blue flag iris (Iris versicolor) replaces yellow flag iris
- Serviceberry (Amelanchier arborea) replaces shrub-like honeysuckle
- Golden Alexander (Zizia aurea) replaces bishop’s weed
- Trumpet creeper (Campsis radicans) replaces oriental bittersweet

Citations and for more info:
http://www.newfs.org/images/protect/Invasive%20Brochure%20Reduced%20File%20Size.pdf
https://www.mass.gov/service-details/invasive-plants
https://www.pri.org/stories/2016-06-04/invasive-species-threatening-new-englands-plant-life