This thing is keeping me awake. Tremendously thick today. Thanks folks for hints on 1 down . Wouldn't mind but I sold the damned stuff for 40 years in our health food shop. It ain't a marshland plant by the way. One of its folk names is grecian hay. I've a lovely (Indian) recipe for potatoes using it. Make enough for two meals and the family raid it cold the following day.
Oh I forgot I'm actually stuck down in the south west corner. Hints please on either 17d, My one opal improves on exhibits here (7) or 20a Live as a couple and smile about evening in America (2,2,4) See, I told you I was thick tonight. I'll thank any answers in the morning.