Complex sentence: In the bird seed market, Nyjer is often sold or referred to as thistle seed, a misnomer due to early marketing of the seed to take advantage of the finches' preference for thistle.
Split into simpler sentences: In the bird seed market, Nyjer is often sold or referred to as thistle seed. This is a misnomer due to early marketing of the seed as'thistle' to take advantage of the finches' preference for thistle.