Geum urbanum, Wood Avens is also widely known as Herb Bennet. A member of the Rose family the genus Geum is commonly known as Avens, it is very closely related to the Potentilla (Barren Strawberries) and the Fragaria (Strawberries) a relationship reflected in the shape of the flower.
The species name urbanum just means urban (of the town or city). It is a species closely associated with man as it grows well on disturbed ground but also the burrs that carry the seeds tend to stick to men and their livestock and so follow them around.
Locally Wood Avens is a plant of woodland edge and hedgerow.
I am going to look at how the small strawberry like flower develops into the hooked burr that is the seed head but first we should have a quick look at the calyx.
The calyx is made up of five sepals. Between each of the large sepals is a small bract called an episepal and they form an additional structure called the epicalyx. The sepals that form the calyx are there to enclose and protect the flower as it develops. The epicalyx just seems to add extra protection.
The flower has five yellow petals, they are widely spaced like those of the Barren Strawberry. A ring of yellow stamens enclose the green, multiple styles that will become the burr.
As the flower matures the styles turn from green to brown.
The petals drop off, Seeds are developing at the base of the styles and the styles are becoming kinked and hooked at the tips.
All that remains of the flower is the burr which will attach itself to a passing animal and so disperse.
The whole of the plant is slightly hairy. The leaves are quite variable. At the base of the plant the leaves are quite rounded with toothed edges. They are trefoil, having a large leaf with two smaller leaves set at right angles at the base of the leaf stem.
As you move up the plant the trefoil aspect of the main leaf becomes more obvious.
At the top of the plant the trefoil nature of the main leaf seems to be abandoned and we are left with a single, toothed, lance shaped leaf with the two smaller leaves still at the base of the stem.
The name Herb Bennet comes from an older name Herba benedicta which simply means Blessed Herb. The root of the plant was once worn as an amulet to protect from evil. It was believed that if you kept the root in your house then Satan could not enter and that a man wearing such an amulet was immune to the poison of beasts.
The root.
The roots were also widely used in medicine, dried and powdered they were used to prevent stomach ills and to cure poisoning and when boiled with wine a cordial was made to protect against plague.
Kingdom: Plantae
Order: Rosales
Family: Rosaceae
Genus: Geum
Species: Geum urbanum