The answer is the pigment red
Incomplete dominance is when the dominant allele is not fully dominant over the recessive allele. This results in three phenotype options rather than three. in this case T= tall, t= short and the two combined would be an intermediate height. A punnet square can help you figure this out.
T t
T TT Tt
t Tt tt
In this case you have one genotype that is two tall (TT) alleles. This will present as a tall plant.
The second genotype present is two short alleles (tt). You have one of these that will result in a short plant.
The third genotype present is one of each (Tt). This will result in an intermediate height plant. This shows up twice in the punnet square.
Based on this you will have 25% tall, 25% short and 50% intermediate.
<em>adaptive radiation formed many new land plant species</em>
