Every Wednesday, I hope to find a new ‘weed’ to investigate. My only criterion will be that I will not have deliberately planted the subject of our inquiry. Who knows what we will find…..

Dear Readers, I am always surprised at what turns up along the dark, gravelly path that leads to the side entrance of my house. Yellow corydalis, greater celandine, forget-me-not, buddleia, Mexican fleabane, Canadian fleabane, sow thistle and chickweed all put in an appearance, but this is the first time that I have spotted this little beauty – Broad-leaved Willowherb (Epilobium montanum). I have a garden full of Great Willowherb, but this plant passed me by. It has a delicate, shy habit that means that it is often overlooked but once I’d noticed it, I realised that it was everywhere.

The plant has four, deeply-notched mauve-ish petals, and the stigma in the centre form a distinctive four-lobed shape. The leaves are rounded at the bottom (hence the ‘broad-leaved’), and are practically stemless.  Like most of the other willowherbs, it’s native.

As with all the willowherbs, the soft leaves seem irresistible to insects, and the plant that I used for identifications was covered in enthusiastic greenfly. However, the genus is also subject to the depredations of some larger creatures, such as the caterpillars of the Small Phoenix:

the Striped Hawkmoth:

and, most spectacularly, the Elephant Hawkmoth and the Small Elephant Hawkmoth, shown below:

Plants of the Epilobium genus have long been used as a treatment for prostate and urinary complaints, and indeed a company which manufactures supplements made from willowherb has taken the genus name of Epilobium  for its company name (note that this is not an endorsement).  Although the showier members of the family are the ones most often used in herbal medicine, Broad-leaved Willowherb was singled out in an Austrian study as having a stronger effect than the others. While there is a lot of interest in Chinese herbal medicine and Ayurveda, herbal medicine in the West is still seen as something of a niche area. Maybe this is because when something grows all around us, it’s difficult to make money from it.

I love Rosebay Willowherb and Great Willowherb.  I admire the way that they can take over a spot of damaged and derelict land and turn it into a sea of cerise. But this little plant lurks in the interstices of the city, at the bottom of walls, in the crevices and the dark places, cheering them up with its mauve flowers and graceful habit. And, when the time is right, it fires its fluffy seeds with just as much vigour as its bigger relatives. It might be little, but it’s a plant with ambition.