The answer is ROMAINE, seven letters. Lettuce is one species, Lactuca sativa, bred into four broad shapes, and the variety names puzzles use are really the names of those shapes. ROMAINE covers the upright one, with COS and BIBB taking the short slots.
Four shapes, one plant
Every lettuce in an American supermarket is the same species, selected for how its leaves sit. Crisphead grows a dense round ball of pale, watery leaves that snap, and iceberg is the famous member. Butterhead forms a loose soft head whose leaves feel faintly oily, which is where Bibb and Boston belong. Romaine, called cos in Britain, grows upright in a tall bundle with a thick white rib up the middle of each leaf. Loose leaf never forms a head at all and is picked leaf by leaf, covering oakleaf and the red and green leaf types.
Learning those four groups turns a long list of variety names into four buckets, and nearly every answer a puzzle wants lands in one of them.
Why romaine holds a Caesar together
The rib does it. A romaine leaf is built around a thick central spine that stays rigid after dressing hits it, and the blade curves away from that spine into a shallow trough. The shape carries a heavy emulsified dressing without going limp, which is why the salad that depends most on a heavy dressing settled on that lettuce rather than on a soft butterhead.
Iceberg earns its place a different way. Its appeal was never flavor, of which it has very little, but a cold wet crunch nothing else delivers. That texture is why it survives on burgers and in wedge salads decades after cooks started dismissing it as empty, and why the dismissal never quite took.
Why lettuce turns bitter
Lettuce is a cool season crop. When the weather heats up the plant stops making leaves and starts pushing up a flower stalk, a shift growers call bolting, and the leaves toughen and turn bitter as the plant redirects its energy.
That is the whole reason lettuce is a spring and autumn crop across most of the country, and the reason a garden row that tasted sweet in May tastes harsh by July. Nothing has gone wrong with it. The plant has simply moved on to the next stage of its own life, and the leaves are no longer the point.
Which name fits the slot
These names are valuable to a constructor precisely because one category spreads across so many lengths.
| Letters | Answer | Group or note |
|---|---|---|
| 3 | COS | British name for romaine |
| 4 | BIBB | Small tender butterhead |
| 6 | BOSTON | Another butterhead |
| 6 | BUTTER | The group name, shortened |
| 7 | ROMAINE | Upright, thick ribbed |
| 7 | ICEBERG | The crisphead standard |
| 7 | OAKLEAF | A loose leaf type |
| 7 | MESCLUN | A mix of young leaves, not a variety |
| 9 | CRISPHEAD | The group iceberg belongs to |
COS is the most useful of them, because three letter slots are the hardest to fill and most American solvers meet the word nowhere else. MESCLUN is the one that misleads, since it names a blend rather than a type, so a clue reaching for it will mention a mix or a spring salad. Anything naming Caesar, a rib or an upright head is ROMAINE.
