Ragged, lobed leaves and closed-up yellow tubular heads with black-tipped bracts, turning to a white fluffy 'old man' seed head
Groundsel - Senecio vulgaris.
Nature · Wildflowers & flowers
Groundsel
Native · annual, flowers all year · gardens, arable fields, waste ground
Senecio vulgaris — Asteraceae
Groundsel is the small, ragged-leaved annual that seeds itself through borders and pavements in every month of the year. Its yellow heads never open into rays but stay as tight tubes, with black-tipped bracts, before turning into white fluffy seed heads - hence the genus name Senecio, 'old man'.
How to spot them
- ▸Cylindrical, tube-shaped heads of yellow florets that never spread out into rays
- ▸Black tips to the small bracts at the base of each head
- ▸Ragged, deeply lobed, hairless leaves, the upper ones clasping the stem
- ▸Fluffy white seed heads like a tiny dandelion clock
- ▸Look-alikes: sticky groundsel is sticky-hairy and smelly; heath groundsel is hairier; Oxford ragwort has big heads with spreading rays; the radiate form of groundsel has short curled rays
How to know it
Its genus name comes from Latin for 'old man', a reference to the white hair of the seed head
Groundsel - Senecio from senex.
A popular treat for cage-birds, like chickweed
Groundsel.
The Old English name is thought to mean 'ground-swallower', for the way it overruns cultivated soil
Groundsel - grundeswylige.
Crossing with a ragwort that escaped from a university botanic garden gave rise to a new British species, found in York in 1979
Groundsel x Oxford ragwort gave York radiate groundsel, Senecio eboracensis.
It was the first weed shown to have evolved resistance to a herbicide, simazine, in the late 1960s
Groundsel.
Quick-fire facts
- •Family Asteraceae; a member of the same genus as ragworts
- •Wildlife Trusts: flowers January to December; up to 40 cm
- •Shares with common ragwort the cinnabar moth, whose caterpillars sometimes feed on it, and carries the same class of toxins, pyrrolizidine alkaloids
- •Senecio derives from Latin senex, 'old man'; the name of the plant in Old English was grundeswylige
- •Hybridisation with Oxford ragwort gave rise to York radiate groundsel (Senecio eboracensis)
- •A short-lived annual that can complete several generations in a year
- •Attacked by a rust fungus, Puccinia lagenophorae, which produces orange blisters on the leaves
- •The first documented herbicide-resistant weed was a triazine-resistant groundsel, in the USA in the late 1960s
Drill it — 6 cards
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Sources
- The Wildlife Trusts — Groundsel