Helminthotheca echioides (Bristly Oxtongue)

Plant profiles
Picture of Helminthotheca echioides (Bristly Oxtongue)
Helminthotheca echioides (Bristly Oxtongue)

This week’s #SxPOTW is a common plant that is easily recognised, even when not in flower. It has distinctive blisters on the leaves and is one of our archetypal ‘weeds’, favouring the most unsavoury habitats amongst the debris and rubbish of waste ground. It is found throughout the county except on the most acid soils.

Picture of Helminthotheca echioides (Bristly Oxtongue) leaf
Helminthotheca echioides (Bristly Oxtongue) leaf
Distribution map of Helminthotheca echioides (Bristly Oxtongue) in Sussex
Distribution of Helminthotheca echioides (Bristly Oxtongue) in Sussex

Archaeophyte. Sx: very common. Roadsides; disturbed and waste places; arable fields and other habitats. Records in W-Dod (1937) and Hall (1980) show a distribution concentrated in the south of Sx, and it was thought to be especially frequent near the sea and on chalk. However, although still most abundant to the south, the map confirms that it has recently become widely distributed across the whole of Sx except on the most acid soils.

Source: Helminthotheca echioides (L.) Holub Bristly Oxtongue, The Flora of Sussex (2018)

Many may not recognise its Latin binomial: until recently it had been known as Picris echioides, but this changed ten years ago after the APG III (2009) revisions were accepted by Stace’s third edition of his Flora (2010). The specific epithet, echioides, refers to the fact that the leaves are similarly blistered to those of Echium vulgare (Viper’s Bugloss), however the genus name Echium derives from the Greek for ‘viper’s head’ which was bestowed by Dioscorides who thought the nutlets of the plant resembled a viper’s head (although some dispute this, suggesting it is the long, forked style of the flowers resembling a viper’s tongue that clinched it).

Picris hieracioides (Hawkweed Oxtongue) remains our only member of the Picris genus. It is native, unlike H. echioides, which is an archaeophyte. The main difference is seen in the outer phyllaries which are ovate/cordate in H. echioides and unmistakable, whereas those of P. hieracioides are all similarly lanceolate and not cordate at the base.

Picture of Picris hieracioides (Hawkweed Oxtongue)
Picris hieracioides ssp hieracioides (Hawkweed Oxtongue)
Distribution map of Picris hieracioides (Hawkweed Oxtongue) in Sussex
Distribution of Picris hieracioides (Hawkweed Oxtongue) in Sussex

It is less common and exists as four subspecies in the UK, although two are rare.