meadowsweet and great burnet leaves 
Floodplain meadow in early July 
Floodplain meadow in early May
Find a meadow with a lot of Meadowsweet (Filipendula ulmaria) and Great Burnet (Sanguisorba officinalis) and you have hit botanical gold. These are the key species that shout “floodplain grassland of good quality” in Gloucestershire. Sure, you’d hope to find other indicator species as well, but these get you off to a flying start.
They are easy enough to identify in summer when they are tall plants in full bloom but surveyors should become familiar with what they look like earlier in the year, in April and May, when they are just ankle-height leaves.
The photo with the 10cm ruler shows one leaf of Meadowsweet on the left and one leaf of Great Burnet on the right. They are compound leaves, so the separate green portions are all just leaflets of a single leaf.
These two species often grow together, and in spring you might need to look carefully to decide which you have.
The Meadowsweet leaf is coarser with pleated leaflets and the parallel side-veins on the leaflets showing clearly.
The Great Burnet leaflets may be folded in half, but won’t show the concertina folding. The leaflets are often heart-shaped and attach to the main leaf stem via a bare stalk. The veins are not nearly so obvious.
Both can have quite a lot of red pigmentation on the leaf stem and leaflets when young. Great Burnet leaflets in particular can look almost silver when they catch the light.
Fun fact:
Meadowsweet was one of the mediaeval strewing herbs that were scattered on the
floor of the halls. This wasn’t particularly the flowers, which are foamy and white
and have a honey smell, but the leaves and stems which have a pleasant but strong
odour of ripe cucumber with maybe a nip of antiseptic. Great Burnet leaves also
smell of cucumber, but to me it is a less complex scent, perhaps like under-ripe
cucumber skin.
Juliet Bailey