Answer: 'Bowles' Mauve' is a hybrid evergreen perennial form of Erysimum and does not reseed like the more common biennial wallflowers. It does root quite easily from cuttings though, which is a good thing as the plant is not very longlived. It quite literally blooms itself to death after a couple of seasons - 2-3 years is about as long as you can expect for good performance before it starts to decline. I'd take tip cuttings or replace the plant with a new one.
The story is the same for your zebra mallow. An old Cottage-garden favorite, this cousin to the Hollyhock has similar satiny flowers in a soft lavender-purple shade, exotically striped with deep maroon veins. It forms an upright, bushy mound that may need to be staked if grown in rich soil. This is a short-lived perennial or biennial, often flowering itself to death in the first year, but coming back the next year from self-sown seedlings. I'd allow the seeds to develop and spill into the garden bed. Next spring you'll have lots of new plants.
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