H. vulgare may have a mutant allele for any of the enzymes of the chlorophyll biosyntheis pathway which may in the presence recessive allele of Spontaneum produced a deformed/nonfunctional enzyme molecule or vice versa. This explanation is true under single gene control of the trait which may be confirmed through molecular analysis only as advancing of generation is not practical to see the inheritance in this case.

There are certain reports that many chemical like organophosphates induce chrophyll mutation in H vulgare.

Another reason may be the due to the interaction of organelle genome and cytoplasm from other species.

Sometimes due to transgressive segregation (exceeds both parental limits), the lower extremes express albinos due to all allees are in reccessive condition.