I found this plant flowering very unexpectedly one morning. The flower closed and dried up by the next morning so I was glad I didn’t procrastinate with taking the pictures!
The bud had been in on the stem for a long time and did not bloom. The day before the bud bloomed I dosed the (heavily planted) tank with Crystal Clears Fertilizer and, low and behold, I find the bud open. Now there are several more buds and I am just waiting to get them to grow fully before I add more ferts.
Anyway, just thought I would share this with everyone.