PLANT OF THE MONTH: Yellow Rattle

Latin name: Rhinanthus minor

Distribution: widespread, common, grassland

Flowering time: May-June

Description

Yellow rattle is an annual wild flower that thrives in grasslands. It has yellow, tube-like flowers protruding from an inflated, green structure called the calyx. It has serrated leaves (that look a little bit like tough elongated nettle leaves) which sprout opposite each other all the way up the stem. Grows 5 – 18 ins (12 – 50 cm) high. 

When the flowers of yellow-rattle fade, the brown calyxes stay visible and harden and inside the tiny seeds ripen and give a distinctive 'rattle', when you shake them. 

Common names

The name “rhinanthus” comes from two Greek words meaning nose and flower, due to the projecting beak of the upper portion of the flower. Yellow rattle is also known as Cock’s Comb and Penny Grass and is a member of the Figwort family.

Herbal Uses

Yellow Rattle is allegedly good for coughs and dimness of sight. The ripening seeds of yellow provide food for the caterpillars of the Grass Rivulet moth, which live inside the seed capsules before they overwinter as pupae underground.

Ecological Importance

Yellow rattle is known as ‘the meadow maker’ or ‘nature’s lawnmower’. The UK charity PlantLife states that yellow rattle is the most important plant you must establish when creating a wildflower meadow.

This is because it is a semi-parasitic plant that feeds off nearby grasses. For this reason, while it was once seen as an indicator of poor grassland by farmers, it is now often used to turn improved grassland back into meadow: by diverting water and nutrients from the roots of surrounding grasses it can suppress their growth by up to 60%. In this way, it creates space for more delicate plants to push their way through and thrive.

Yellow Rattle at Rosamund Garden

We were lucky enough to work with BugLife last year to introduce yellow rattle into our orchard at Rosamund Garden, as part of our project to increase biodiversity in the garden. BugLife provided very fresh, locally grown seed and helped a group of our volunteers to scarify strips across the grass in the meadow with hoes, rakes and a hand mower one rainy day last November. The seed was sown immediately in time to vernalize in the winter frosts. 

Just as we finished sowing a huge vibrant rainbow emerged to bless us, and I am pleased to say we have been rewarded with a fantastic germination rate and gorgeous swathes of yellow rattle in our orchard this June. You can see how much it has suppressed the grass where it has been planted. This autumn we will collect our own seed and repeat the process in new areas. 

Huge thanks to Louis Harrington Edmans at BugLife for supporting our project and to all the volunteers who helped with the backbreaking work!