In my garden these are under 14 inches and all of them are perennial:
Pretty, pretty, pretty!
12- 18 inches according to the database, mine are shorter.
Short but with quite large blooms.
Very hardy and good for naturalising.
Common chives in case you do not grow these already... Edible of course. Also available with white blooms.
Has interesting, evergreen foliage. Needs well draining soil.
Both flowers and leaves are edible. (Not to be confused with Convallaria majalis/Lily of the Valley or Colchicum autumnale/False Autumn Crocus, which are both poisonous!!) Large patches will give off a strong garlic smell when dying down, so plant small groups if you want them close to where you like to sit in your garden. Likely to spread.