Very tricky. Common names can be very localized. Unfortunately the real scientific name can be hard to pronounce, spell or remember much of the time. In addition, the official nomenclature changes too often. If I can learn that name from the beginning, then I can use it. Most of the time the introduction to a plant is under a common name and it's hard to switch. Sometimes the common name is wrong and I know it's wrong but it's all I have. I was given Ledebouria socialis as Pregnant Onion. I knew it wasn't, but it took several years of searching Google photos before I found a correct picture and tracked down the name. If I lived closer to specialty nurseries or even larger ones I might have come across it sooner. I have trouble remembering it's called Silver Quill, so it's a case where I learned the scientific name. That's how I learned Sesbania, too, but then they changed it and I can't ever remember the correct name. So there I actually use Bladder Pod some, though I don't think that's very good either. If you asked me, I'd probably call it Sesbania because I'd have trouble remembering the common name offhand. That gets a lot worse as I get older. I, in fact, can't ever remember any name for the Ipomopsis rubra. I recognize it visually, but I have to wait to look up the name(s). It's just that tall, red spire native wildflower
most of the time.