Rough Chervil (Chaerophyllum temulum)

Rough Chervil (Chaerophyllum temulum), here seen, as often, emerging out of a hedge.

In early June, just as the flowers of Cow Parsley (Anthriscus sylvestris) are disappearing, little patches of Rough Chervil begin to show up. Rough Chervil is invariably described as "the" successor to Cow Parsley because, of the various umbellifers around in mid June, it's the one that most resembles CP - i.e. medium size, and divided leaves with a somewhat fern-like appearance.

But, common plant as it is, it has nothing like the ubiquity of Cow Parsley.  That's a measure of how much things have changed in six weeks.  Basically, how much more STUFF there is. The plants of spring have a blank canvas to work on. Now the leaves have spread on the overhanging trees, shading out many of the sites where Cow Parsley flourished. The hedgerows are bursting outwards. Above all, the grass is up. Not to mention the nettles, and the brambles, and the larger umbellifers like Hogweed and Hemlock....  So, comparatively speaking, Rough Chervil is just a here-and there kind of plant.
 
Date aside, you can tell Rough Chervil from Cow Parsley, even at a distance, because the umbels look brilliant white and are kind of dotty (i.e. the "umbellules" are well separated from each other). On their dark stems, they often appear to hover in mid-air.

Above and below, an umbel. I'm always struck by something small and dainty about the flowers. I think I associate them with memories of my great-aunt Joan, who kept miniature dachshunds; she was a dancer in her youth.

(Above) Close-up of an umbellule. If you click the photo to enlarge it you can see how the stamens of the innermost flowers haven't yet split open to reveal their pollen, they still look greeny-white and withdrawn.

(Above and below). Young fruits developing. I took these photos yesterday (26th June 2013).

(Above and below) Stem and stem-leaf - "Rough", of course.  Commonly the stem is only red-blotched, but this one was more or less solid red. The leaves (again in comparison to similar species) strike me as sort of rounded at the corners. Blunt is the word I'm looking for.

(Below) A leaf further down the plant. Emboldened by my experiment (five minutes earlier) with Wall Lettuce, I decided to try eating a leaf. Mmm - a bit hairy, but really not bad, not bad at all... UH-OH! Turns out that Rough Chervil is apparently somewhat toxic - though it doesn't say this in any of my Field Guides  - not in the Hemlock class maybe, but capable of damaging your nervous system. (After 24 hours it has had no effect on me at all; I guess I didn't eat very much.)

So OK, I should've checked first.  (Memo: Do NOT play games with the Apiaceae!). Like others before me, I mistakenly assumed that Rough Chervil must be just a harmless wild variant of the garden pot-herb. (Its English name was probably intended to distinguish it from "Wild Chervil", an alternative name for Cow Parsley that is now obsolescent in the UK, though I think it is still used in the USA. Cow Parsley has endless local names. I've just read about "Mother Die" (Lincolnshire) and "Lucky-By-Brain" (Devon) on Weaver's blog.