Square-stalked Willowherb - Epilobium tetragonum

Alternative names
Square-stemmed Willowherb

Medium to tall plant with long strap shaped, toothed leaves. The pink flowers have four notched petals and a club shaped stigma. The stem is square and the fruit capsules are 7 to 10 cm long.

Similar Species

One of four similar species; E obscurum, E roseum and E ciliatum also have club-shaped stigma.   E roseum has many glandular hairs and longer petioles, and is on the VC55 Rare Plant Register.  E obscurum has few glandular hairs and perennates with leafy stolons. E ciliatum has numerous glandular hairs on the upper parts of the stem, sepals and parts of the fruits, and perennates with dense leafy basal rosettes.   Hybrids also occur.

Identification difficulty
Recording advice

The County Recorder has asked for a specimen of this plant to be retained for verification


Damp areas such as ditches, stream sides and woodland clearings.

When to see it

July and August.

Life History


UK Status

Fairly frequent in lowland England and Wales north to Yorkshire.

VC55 Status

Occasional in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 53 of the 617 tetrads

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Leicestershire & Rutland Map


Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

UK Map