Go Botany
This site from the Native Plant Trust is the pre-eminent resource for identifying any vascular plant found in New England. The searchable database includes comprehensive plant keys for identifying a species based on a variety of features, from growth form to flower shape to fruit type, with photos that document all of these features. Species pages include New England-centric distribution maps and valuable notes on common look-a-likes. Don’t forget to use their ‘Ask the Botanist’ portal for expert insight into your plant ID queries.