Plantaginaceae · Plantain family

Plant family guide

Start with Foxglove

Foxglove (Digitalis purpurea) is one of the most recognisable British members of Plantaginaceae. Its tall raceme of hanging tubular flowers looks very different from a plantain or a speedwell, which shows just how varied this family can be.

Older books may place Foxglove in Scrophulariaceae, the figwort family. Modern botanical classification places Digitalis in Plantaginaceae.

Foxglove spike with purple-pink tubular flowers — Foxglove (*Digitalis purpurea*): large tubular flowers arranged along a tall, usually one-sided raceme.

Key family attributes

Flowers: usually bisexual and zygomorphic (bilaterally symmetrical). The petals are normally fused, often forming a tube or a two-lipped opening. Most flowers are built from four or five parts. Plantains (Plantago) are an important exception, with small, reduced, more radially symmetrical flowers.
Stamens: commonly four, often arranged as two pairs of unequal length. Speedwells (Veronica) are a useful exception because they usually have only two stamens.
Leaves: simple and without stipules. Their arrangement varies widely across the family and may be basal, alternate or opposite, which is one reason the different genera can look so unlike one another.
Ovary and fruit: the ovary is usually superior and formed from two fused carpels. The fruit is most often a dry capsule, with one to many seeds; the way the capsule opens varies between genera.

Features to look for in the field

Joined petals

Fused petals are one of the most useful recurring characters. In Foxglove they form a large bell-shaped tube, while toadflaxes have a two-lipped flower and speedwells have a much smaller, more open corolla.

Few stamens

Look for four stamens in many members of the family, often in two unequal pairs. Speedwells stand out by having only two, making stamen number a useful clue when comparing genera.

Capsule fruits

Dry capsules are common throughout Plantaginaceae. Foxglove develops upright capsules along the old flower spike, while other genera use different capsule-opening mechanisms.

Look closely at Foxglove

Follow the flower spike: flowers normally open from the bottom upwards, leaving capsules below and unopened buds above.
Look inside a flower: the pale throat is patterned with dark spots that help guide pollinating insects.
Check the leaves: the broad leaves are softly hairy, strongly veined and toothed, forming a basal rosette before the flowering stem develops.

A surprisingly varied family

Plantaginaceae is a good reminder that a plant family does not always have an obvious single "look". Foxglove, Ribwort Plantain, Germander Speedwell and Common Toadflax can appear unrelated at first glance.

When learning the family, compare flower construction, fruit and other structural details rather than relying only on flower colour or the overall outline of the plant.

Plantaginaceae flowers in this guide

Explore the individual flower pages for more photographs and identification details.

Foxglove

Digitalis purpurea

Family: Plantaginaceae

Flowering: June, July, August, September

Common Foxglove with tall spikes of purple-pink tubular flowers

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