The composite picture posted above is comprised of cropped-sections from four images on JK's Flickr website. So, you've seen them before - but not from the same perspective.
To paraphrase the old saying, it is sometimes hard to see the trees due to the forest.
Since I couldn't download those images from JK's Flickr site, I had to "print" a pdf of each image-screen and then crop the section of the pdfs that displayed only key elements necessary for ID.
I made my original ID-assessment based on the population's growth pattern (upper-left), the bladders (which are unique to Utricularia spp), the stems' branching-characteristics (top-right) and the absence of flattened leaves (which would have certainly confused the ID with Najas).
PF: I sent the composite image to Mr. DiTomaso last night. I'll forward his reply to you.
I'll concede that plant-IDs from digital-images are sometimes tricky - especially when image-resolution and perspective is lacking. Tell-tail features are always the "key". Sometimes, they're present - sometimes not. I can't make a positive ID all the time, even after lots of practice. But, images are usually much better than phone-descriptions.
