chauncey said:
Is oblivious that I can't do anything expensive or fancy.
Fancy isn't the point. The light is flat and directionless here. All you need to do is to create directionality to the light. This image is a really good documentary representation of the plants, but we don't really get their character.
Bring the lights in from off axis, and from a single side. Use 2-3 on one side. Use one of the four for "fill" from the opposite side. If you used 2 on one side, one for fill, then you could even use one for a back light to gain separation from the black background.
Seriously, given the lights and the size of the subject, it's a matter of moving your lights just a few inches here and you would raise the game tremendously.
Photography is all about seeing the light and making it work for you, whether you're photographing flowers, bugs, people, or mountains.