I'm delighted to see several Smyrnium perfoliatum have sprung up in the garden. I tried to introduce this beautiful woodlander several years ago and thought I'd failed. My first attempt was to plant three I purchased in pots but they didn't flower and died. 

 Then I bought one in flower that looked like it was just past its best and about to go to seed. I'd read somewhere that the seed has to be absolutely fresh for propagation purposes and the best bet is to let them self-seed. Nothing came of it- or so I thought. Smyrnium perfoliatum is often described as biennial but more accurately it's a triennial i.e. three year growth cycle. Some seed must have germinated.

 Thinking about it I saw a couple coming through last year which didn't amount to anything but that must have been the second year's growth. According to one source S. perfoliatum grows above ground for about six weeks each year till the year it's ready to bloom. Another source says it can be mistaken for Ground Elder when it first appears. About five or six weeks ago I was puzzled to see what looked like Ground Elder and wondered how it got there.

 So it came as a delightful surprise to have three [update: four] very healthy looking specimens put in an appearance. The native range of S. perfoliatum is southern Europe heading east but clearly it can do well in UK conditions albeit a bit tricky to establish. The flowers and upper leaves are of an exquisite hue that falls somewhere between lime green and lemon yellow. They become luminous when the sun is on them.