Grows in similar places to Butterbur (damp woods, beside streams and fresh water).
Many similarities to : Butterbur but that has mauve to purplish flowers whereas White Butterbur has all white flowers. Also the leaves of White Butterbur, although cardiod in outline, can be more elongated, some ending in a blunt point (but others looking similar in shape to those of Butterbur.
Not to be confused with :
Butterwort [a plant of similar name]
No relation to : Pirri-pirri-bur, London Bur-Marigold, Nodding Bur-Marigold,Trifid Bur-Marigold, Bur Chervil, Un-branched Bur-Reed, Branched Bur-Reed
Least Bur-reed [plants with similar names].
White Butterbur is an introduced plant, grown in gardens, but now also growing wild, mainly in the North of the UK, especially in Scotland. It grows in huge colonies, spreading by underground runners or rhizomes.
Just like Butterbur, it is dioecious with the male and female flowers of White Butterbur occur on separate plants, with the female plant being much the rarer. And just like Butterbur, the male plant is shorter than the female and the female flower bundles hardly protrude at all from the green and enveloping bracts. Your Author assumes that the above photos represent just the male plants. It is rare in the south of the UK, but frequent in the north, especially in Scotland.