Epilobium species - Willowherbs

Rosebay Willowherb (Chamerion angustifolium) used to be in this family but is now in a separate genus.

Epilobium hirsutum - Great Willowherb, is a tall plant, usually well over a metre, with large flowers 1.5cm or more across. The stigma is large and 4-lobed. The leaves are decurrent, where the edges of the leaves continue down the stem as raised lines.

Epilobium parviflorum - Hoary Willowherb is smaller than Epilobium hirsutum. The stem is densely hairy and the entire leaves are not decurrent down the stem, rather have rounded bases and are +/- sessile. The stigma has four lobes and may appear to be club-like as they are held sub-erect.

Epilobium montanum - Broad-leaved Willowherb, also has a 4-lobed stigma and 8-10mm flowers. The leaves are ovate and broader with sharp irregular teeth and a pointed apex, rounded base and a short petiole.

Epilobium ciliatum - American Willowherb is usually tinged red, especially the stems which are branched and more rigid. The stem has two or four ridges and patent glandular hairs.

This willowherb has shiny, narrower leaves, gradually tapering to an acute apex, with irregular, forward-pointing teeth, a prominent midrib and a short petiole (<4mm).

The flower can have darker veins on the petals. The stigma is club-shaped.

Epilobium ciliatum and E. montanum are the commonest willowherbs of waste ground and streets.

Epilobium obscurum - Short-fruited Willowherb has glandular hairs only on the sepals and immediatly below. The stem is erect from a curving base and is obscurely 2- or 4-ridged. The fruits noticeably short, 3-6.5cm, with short, curled hairs. The sessile leaves are dull green above, obscurely and distantly toothed. The stigma is club-shaped.

Epilobium palustre - Marsh Willowherb, grows in marshes, fens and ditches and as a plant is slender, delicate, virtually unbranched, inflorescence often drooping with no glandular hairs. The leaves are narrow and taper at both ends, hairless, sometimes purplish below, margins untoothed and downturned. The stigma is club shaped.

Epilobium brunnescens - New Zealand Willowherb, is a plant of stony areas and gravel. The stem creeps along the ground sending single flowers up from the leaf axils. The leaves are round, un-toothed and smooth on top.

The deep pink petals and and stigma which is a white cross are distinctive.

The plant is hairy with long hairs.

Epilobium hirsutum NS6058 17Aug2012 PW

Epilobium hirsutum NS6057 1June2018 PW

The leaves extend slightly down the stem.

Epilobium hirsutum NS537658 28July23 PW

Epilobium parviflorum NS6662 23Jul2020 PW

The flowers are smaller than E. hirsutum and the stigma lobes often sticks together.

Epilobium parviflorum NS5365 04Sep19 PW

The stem is covered with dense sort to medium length hairs.

The leaves are sessile (stalkless), but do not wrap round the stem or go down the stem.

Epilobium parviflorum NS6662 23Jul20 PW

Epilobium ciliatum vs Epilobium parviflorum NS8047 20July2020 PW

Cross-shaped stigma.

Epilobium montanum NS5863 01Aug2015 PW

Leaves are pointed, broad, ovate with a cordate or sub-cordate base and a short petiole 3 - 6mm.

The stem has short patent hairs and some which are arched over.

Epilobium montanum NS5863 01Aug2015 PW

The stem can have 2 - 4 ridges from the base of the distal petiole.

Epilobium ciliatum NS6638 26Aug2017 PW

This shows the club-shaped stigma and sometimes thre are darker vein on the petals.

Epilobium ciliatum NS7951 20July2020 PW

Mid-stem leaves are lanceolate, pointed tip and shortly petiolate. They may be toothed distally.

Epilobium ciliatum NS7951 20July2020 PW

There is a mixture of glandular and eglandular hairs. You need a 10x hand lens to see the hairs clearly.

Epilobium ciliatum NS6638 26Aug2017 PW

Leaves are dull green, pointed ± toothed distally and sessile.

Epilobium obscurum NS8065 21Jul14

Arrows highlighting the club-shaped stigma, the glandular hairs on a sepal and on the “floral collar” below the sepals and above the ovary. Elsewhere on the stem and ovary there are only appressed simple hairs.

Epilobium obscurum NS8065 21Jul14 PW

Epilobium obscurum NS6638 26Aug2017 PW

The club-shaped stigma.

Epilobium palustre NS9208 6Aug2020 MP

The floppy inflorescence in a typical rushy habitat.

d tEpilobium palustre NT0121 20Aug2017 PW

Epilobium brunnescens 31May2017 NS6637 MP

Epilobium brunnescens NT0022 20Aug2017 PW

The leaves are distinctive

Epilobium brunnescens NT0022 20Aug2017 PW

When the flowers have gone and the seed pods open it looks like a model of a windfarm.

Epilobium brunnescens NT0022 20Aug2017 PW

Epilobium brunnescens NS5943 3Aug2018 PW