Furrows or not...I'm sticking with wassellii. Give it LOTS of light...water well when it's active and less water in the winter but still as bright as you can get it. Flowers will follow and we'll have the answer. Good luck w/it!
I can't find my pic from last year but this one is from the bloom in 2014. It grew even bigger after this shot and was just too much to accommodate in my winter space (under lights) so I gave it to a friend who has a g/h. As you can see, when it gets some age on it and it's happy...it puts on quite the show. It would give me 2 flushes of blooms like this early in the summer.
The flowers aren't very long lived individually (about 10 days) but the 2 flushes of flowers had it blooming for about a month. I loved the spidery flowers.