Treacle-mustard

Treacle-mustard - Erysimum cheiranthoides

Description

Short to medium hairy plant with square stem. Leaves oblong, or lanceolate, untoothed to deeply toothed, but soon withering, stem leaves pointed, ascending. Flowers small, yellow, 5 to 6 mm. Fruit 10 to 50 mm, often slightly curved and square in section.

Similar Species

other yellow crucifers

Identification difficulty
ID checklist (your specimen should have all of these features)

Seed-pods long and 'erecto-patent') - i.e sticking out at an angle from stem; seed-pods without beak, splitting into 2 valves with usually one row of seeds in each valve.  Hairy; hairs are stellate (i.e. branched).  Lower leaves entire, toothed

Recording advice

Photos of whole plant in habitat, and detailed photos of flowers and seed-pods. Either obtain confirmation from a County Recorder before submitting a record, or submit detailed images showing key features.  The County Recorder may wish to see a specimen for confirmation. (RPR).

Habitat

Waste places and road sides.

When to see it

June to August.

Life History

Annual.

UK Status

Fairly frequent in lowland England, scarcer elsewhere in Britain.

VC55 Status

Scarce and declining in Leicestershire and Rutland; threatened by agricultural herbicides.

In the Flora of Leicestershire (Primavesi and Evans 1988) it was found in 37 of the 617 tetrads, and in the Flora of Rutland (Messenger 1971) in 7  tetrads.

In the current Checklist (Jeeves, 2011) it is listed as Alien (neophyte); occasional.

It is listed on the current VC55 Rare Plant Register (Hall and Woodward 2022) as Locally Scarce (i.e. present in 4-10 sites)

Leicestershire & Rutland Map

MAP KEY:

Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2025+ | 2020-2024 | pre-2020

UK Map

Additional images

All NatureSpot records