Saturday, May 12, 2007

Herb Robert Geranium robertianum

I am an amateur attempting to discover the identity of everything that lives in my garden.

Photo's 1 and 2 (click to enlarge) show a weed that grows beneath the hedge at the rear of my garden (specifically, at (0.8,2.0) - see here). Turning to my copy of The Wild Flower Key (Francis Rose, publ. Penguin Books) I'm confident my weed is Herb Robert (Geranium robertianum).

Herb Robert is part of the Crane's Bill Geraniums, so-called as apparently the seed cases have that shape. I don't have a photo of this but will try to post one later in the season when the seed cases are well developed.

Left undisturbed Herb Robert has no particular smell, but bruise the leaves and a pungent odour emerges that, to my nose at least, is a cross between ginger and cat pee! Despite this off-putting feature, it seems some are happy to use Herb Robert as a herbal 'tonic' and it gets a mention in the famous writings of the 17th century English herbalist Nicholas Culpeper:

"Herb robert is commended....to stay-the-blood; it speedily heals all green wounds, and is effectual in old ulcers in the privy part"

Not advice I can endorse!

An obvious and intriguing question is who was Robert? Here, I have to say my web searches have drawn blank. According to this site possible candidates are a French monk Robert of Molesme (d.1110); Robert Duke of Normandy (d.1134) or a Bavarian St. Rupert of Salzberg (d.718). Whether these are the only candidates and which has the honour of being the one, true 'Bob I haven't been able to determine. If you're reading this and know, please leave a comment.

Richard Tofts has put a scholarly review of Herb Robert's biology online, from which I learn that the British Isles can be divided up into about 3,500 10x10km squares, and that you'll find Herb Robert in just about all of them. This prodigious ability to spread and colonise has led to G. robertianum becoming a serious problem-weed in woodland in the USA, where it is an introduced species.

For a fascinating photo of a Herb Flower taken in ultra-violet light (a region of the spectrum into which which many insects can see) see here. If you'll permit me a moment of hubris however, I have to say one of the prettiest photo's of Herb Robert I've seen is the one that emerged when I put a flower under my microscope at 40x magnification (photo 3) and saw the dozens of tiny yellow pollen balls clustering the flower's reddish-purple anthers (the presence of red or orange anthers identifies my plant as G. robertianum incidentally, rather than the similar-looking, though somewhat smaller, Little Robin (G. purpureum) which has yellow anthers).

Though to many gardeners it is a weed I shall leave my Herb Robert growing under my hedge. You never know when the ability to prepare a poultice that smells like cat pee is going to come in handy!

6 comments:

Duxbury Ramblers said...

Many thanks for your comment on the Herb Robert - I am impressed by your macro photography - I only usually have a compact with me on our rambles but if I have seen something I think might be of interest I will take my DSLR the Sony A100.
Just getting use to it but I am happy with the results so far.

The Duxbury Ramblers.

Richard Carter, FCD said...

I also managed to identify Herb Robert for the first time this week. You can see my photo here.

Pam in Tucson said...

Thank you for dropping by my blog. I'm an ex-pat Brit.and miss England very much, although I do love my desert surroundings. I've bookmarked your very interesting blog for further reading.

Henry Walloon said...

Thanks to all of you for dropping by my site.

To the Duxberry Rarmblers: my technique for the microscope photo's is actually decidedly humble - hold my cheap Olympus digital camera up to the eyepiece of my microscope and snap away until a hlaf-decent photo emerges.

Richard: thanks for the commment and thanks also for alerting me to the existence of the excellent fcd site.

Pam: Thanks for the kind words. "Desert surroundings" was not so far short of the conditions here in Oxfordshire recently - you'd have felt at home! (Happily we've had rain again in recent weeks and the British countryside is back to its full spring green-ness.)

Keith Wilkinson said...

Keith Wilkinson said

Have been researching the life of Robert Floure [Flower] - 1116 - 1218 [Saint Robert of knaresborough, North Yorkshire]. Also found reference elsewhere that 'Herb Robert' was also known at one time as 'The Robert Flower' (amongst many other names. Have not yet established a direct connection - but working on it.

Lee said...

Herb Robert flourishes in my garden. It is excellent ground cover.