Hi Michael - how can I tell the difference between D. longifolia and D. revoluta? I always try to look for D. longifolia, but I actually don't know what I'm looking for ;) Cheers!
The key is in the botanical names. For D. revoluta, the leaves are "revolute". This botanical word means curved or curled back. So for D. revoluta this refers to the edges of the leaves. The leaves of D. longifolia are not curled at the edges.
Ahh so the difference is mostly just regarding the leaves? And not the actual flowers? I had some idea in my mine that "longifolia" meant longer/taller flower stems!
The term "longifolia" refers to the leaves, which tend to be longer for D. longifolia, but this is not a very clear method to recognise them just by itself.