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.