How to do an observation

An observation takes about 30 minutes and when possible, one should observe the flowers of a 100 plants. Take some time, breathe some fresh air, and help to advance research.

Go in to the nature

Take a smartphone/tablet with internet access with you or print out observation form on paper

Find cowslips

Cowslips are common in grasslands, coastal areas, on forest edges and at roadsides

Observe and fill in the online form

Fill in the observation form online


Take photos of yourself and cowslips. Share in social media

Observation with a paper form

To make the observation on paper you need a printed version of the observation form, a pen and a photo camera. Later send the results via the online form on

Keep in mind!

  • Try to mark your specific location (e.g. by clicking the link 'Locate automatically'). Then the scientists can later use this information for further data analysis.
  • Don´t forget to take pictures of the cowslips.
  • There is no need to pick up the plant - just peek inside
  • For ensuring health and safety while doing the observation, follow the local guidelines related to the spread of the Coronavirus Covid-19


How to recognise the cowslip?

The cowslip (Primula veris) is a spring flower. It is a perennial plant, which means that the same plant grows and blossoms in the same place for many years. Species that can be sometimes mixed up with cowslip are the oxlip (Primula elatior) and the common primrose (Primula vulgaris). Primula species can also easily hybridize with each other. Make sure you find the cowslip when making the observation!

The cowslip is an herbaceous plant with the average height range from 10 to 30 cm. It has green elongated leaves up to 20 cm long. One plant can have multiple stems. Cowslip has deep yellow bell-shaped nodding flowers with orange dots in clusters of 5 to 16 blooms together, usually keeping to one side.

How to distinguish the cowslip from other similar species? 

Compared to the oxlip, cowslip’s flowers are smaller, they are bright yellow and small orange spots are visible inside the flower. The flowers of oxlips are usually larger and pale yellow. Cowslip’s flowers are bell-shaped, while the flowers of the oxlip keep are more open. The common primrose has a short stalk and the flowers are very pale yellow or even white. Different primroses are also common plants grown in home gardens and can easily spread from the garden to the wild. They can have flowers of different colors, such as purple, red, orange and pink. Cowslip has only bright yellow flowers in nature. 

Cowslips are one of the first heralds of the spring. It depends on the region and the weather, but it usually begins to blossom at the beginning of May and flowers for a couple of weeks. In cooler weather, the blossoming can also begin later and last until mid-June. In warmer regions, however, flowering can start already in April. 

Where does the cowslip grow? 

The cowslip is quite common in Europe with a Red List status of 'least concern'. However, due to loss of habitats, it is not doing so well anymore. Cowslips prefer dry or moderately moist limey soils, which are more common in coastal areas. However, this does not mean that cowslips do not occur on more acidic soils as well. Cowslips can be found growing in traditionally managed grasslands, parks, forest edges and by the roadside. It usually prefers sunnier spots.

What to do when the flower doesn’t look like either flower type?

Although very rare, it is possible to find such plants that are neither an S-morph or an L-morph. These are so called middle types, where the style and anthers are at the same length - we call them homostyles. Homostylous individuals can evolve during a mutation and all the flowers of the same plant should look the same. If you happen to find such plants, you can skip counting them for the observation, but please let us know about them! You can add a comment to the observation form and add a picture of the homostyle flower but it would be very useful if you send us an email ( with the picture and exact location where the flower was found. This way we can collect a leaf sample for genetic analyses or when possible we ask you to send the leaf material to us. With reporting such findings you can help us understand heterostyly on a whole other level.