This combination photo shows purple loosestrife (Lythrum salicaria), left, and a Liatris spicata, commonly called blazing star or gay feather. Purple Loosestrife is an invasive plant that threatens wetlands and chokes out food sources and habitat for wildlife. TheLiatris spicata is a recommended alternative for invasive purple loosestrife. (Chicago Botanic Garden via AP, left, and Jessica Damiano via AP)