Rhinanthus minor L.

First published in Amoen. Acad. 3: 54 (1756)
This species is accepted
The native range of this species is Europe to Russian Far East. It is an annual and grows primarily in the temperate biome.

Descriptions

Kew Species Profiles

General Description

This pretty little annual sends out roots that grow into the roots of neighbouring grass plants, and steal nutrients from them. It will produce many tiny seeds that rattle around in the papery brown calyx - hence the common name - and it can spread itself year by year, weakening the poor, hard-working grasses that it grows among! But you can get rid of it easily: just cut the flowers before they can produce seed, and the yellow rattle will disappear from your meadow. But if you like variety in your field, keep the rattle; it will weaken the grass, giving other species more chance to survive.

Species Profile
Geography and distribution

Found in Europe, Russia, western Siberia, northern USA and Canada.

Flowering head of the yellow rattle Description

An annual herb, 15-50 cm tall, with roots that penetrate the roots of other plants. The toothed leaves are borne opposite each other on the stem. The flowers are borne above the leaves, and are small and yellow, just peeping out of the inflated green calyx. The calyx turns brown in fruit, and holds the rounded capsule in which the seeds rattle about - hence the common name. Yellow rattle flowers in summer and is pollinated by bumblebees; if that fails, it can fertilize itself. Several varieties have been described, but are now all thought to be part of a single, variable species.

Threats and conservation

Rhinanthus minor is a widespread species, and is currently not under threat. Changes in farming practice will influence this plant; you will not find many in 'improved grassland', but in nutrient-poor, low-lying fields, yellow rattle can be very common.

The conservation of a parasite may not immediately strike people as important. However, recent studies on the impact of R. minor show that annual parasitic plants can play an important role in maintaining species diversity within habitats through differential growth suppression effects and enhanced soil nutrient recycling.

Uses

Yellow rattle is hemi-parasitic on grasses, that is, it can survive independently - but it grows best when drawing some nutrition from the grass roots its roots penetrate. Farmers used to dislike it, as it weakens grass, and it was seen as an indicator of rather poor grassland. But for this very reason it is now used when trying to turn grassland into wildflower meadows. This is done by sowing yellow rattle seeds in the grass. Because they steal food from their neighbours, yellow rattle seedlings can grow very quickly in the spring and also slow the growth of the neighbouring grass plants, so other plants have more chance to survive.

Millennium Seed Bank: Seed storage

Kew's Millennium Seed Bank Partnership aims to save plant life world wide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.

Description of seeds: Average 1,000 seed weight = 2.51 g

Number of seed collections stored in the Millennium Seed Bank: 12

Seed storage behaviour: Orthodox (the seeds of this plant survive drying without significant reduction in their viability, and are therefore amenable to long-term frozen storage such as at the MSB)

Germination testing: 100% germination (germination medium = 1% agar; germination conditions = 6°C, 12/12); 100% germination (pre-sowing treatments = imbibed on 1% agar for 56 days at 2°C; germination medium = 1% agar; germination conditions = 6°C, 12/12)

Wildflower meadow restoration

Yellow rattle seeds were sown alongside Kew'sMillennium Seed Bank atWakehurst in the summer of 2009, as part of work to restore wildflower meadows. The seeds need a long cold period to germinate, and the harsh winter provided the perfect conditions for the plant to flourish and there is now an abundance of the delicate yellow flower, along with other wildflowers such as ox-eye daisy.

Andy Jackson, head of Wakehurst, said: 'The plant is called the yellow rattle because the seeds are held very loosely in a papery cup, and when they mature - which we expect to be around mid-July - they actually rattle'. He added: 'The irises and the yellow rattle are just two of the huge variety of different flowers which will be providing a wealth of colour and natural beauty at Wakehurst this summer'.

Yellow rattle at Kew

Wildflowers, including yellow rattle, can be seen growing alongside Kew's Millennium Seed Bank at Wakehurst in the Loder Valley.

Distribution
Canada, USA
Ecology
Grassland.
Conservation
Rated as of Least Concern (LC).
Hazards

Rhinanthus spp. are reputedly poisonous to livestock and are usually avoided by grazing animals. The seeds contain iridoids which used to be found as toxic contaminants in bread cereals.

[KSP]

Uses

Use
Creation of wildflower meadows.
[KSP]

Common Names

English
Yellow rattle, Yellow-rattle

Sources

  • Herbarium Catalogue Specimens

    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/
  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2022. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2022 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Kew Living Collection Database

    • Common Names from Royal Botanic Gardens, Kew Living Collection https://www.kew.org/
  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2022. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2022 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Kew Science Photographs

    • Copyright applied to individual images
  • Kew Species Profiles

    • Kew Species Profiles
    • http://creativecommons.org/licenses/by-nc-sa/3.0