Pepper Saxifrage - Silaum silaus

Pepper Saxifrage is a member of the Apiaceae family, often referred to as Umbellifers because of their umbrella shaped flower heads. The family includes the ancestors of many of our favourite vegetables and herbs - parsnips, carrots, parsley, celery, fennel, coriander - but also includes the most poisonous plants in Europe, such as hemlock. They are considered fairly challenging to tell apart, but if you know what to look for, most of them are easy.

To identify an umbel to species level you need to note the following:

• are the flowers white or yellow? (If they are yellow it narrows the choice of species down very considerably.)
• are the stems hollow or solid?
• are the stems spotted or tinged with red?
• are the stems ridged or smooth?
• are the stems hairy or hairless?
• does the plant have a distinctive smell?
• how divided are the leaves? Compare the leaf shape to illustrations in a field guide.
• Compare the seed pods to illustrations in a field guide. The seed pods of different species are quite easy to distinguish from one another.
• are there bracts (like small leaves) under the main or secondary umbels?

Scientific Name: Silaum silaus (Apiaceae).

English Name: Pepper-Saxifrage (Umbellifer family).

French Name: Silaus des prés, Fenouil des chevaux (= 'horses fennel') or Cumin des prés (='meadow cumin').

5 Key Characters:

• pale yellow flowers with evenly sized petals in small loose umbels.
• up to 1 m tall.
• solid, ridged stems.
• leaves smell peppery when crushed and have a tiny spike at the tip.
• in grassland prone to waterlogging.

Lookalikes: Hogs Fennel Peucedanum officinale, which has much finer leaves. Cambridge Milk-parsley Selinum carvifolium (you need to compare the seeds, which are quite different, to be sure of distinguishing the two species).

Habitat: Meadows, grasslands, grassy banks, roadsides, on heavy clay.


Flowering Period: June-July-August.

Status: Fairly locally common.

Photographed by Loire Valley Nature:

Basal leaves long stalked with long thin lobes, tipped by a tiny spine.

Flowers pale yellow, no bracts.

Note the bracteoles, almost hidden under the secondary umbels, rather dry and papery looking, and appearing to have black tips in this photo.

Growing in damp rank grassland.

Growing on a roadside ditch.

Seeds collected from the plant above. Note the shape is rounded with ridges but not wings. With thanks to Tim Ford of Aigronne Valley Wildlife for taking these photos for me.

Seeds collected from the plant above. Note the shape is rounded with ridges but not wings. With thanks to Tim Ford of Aigronne Valley Wildlife for taking these photos for me.