This section is from the book "British Wild Flowers - In Their Natural Haunts Vol2-4", by A. R. Horwood. Also available from Amazon: A British Wild Flowers In Their Natural Haunts.
This plant is confined, so far as its present-day distribution is concerned, to the North Temperate Zone, being found in Europe, except Spain, and in Western Asia. In Great Britain it is absent from Pembroke, Mid Lancs, I. of Man, Hebrides, being thus well dispersed south of Elgin. Watson regards it as a doubtful native, and a denizen in North Britain.
Goutweed is doubtless responsible for its distribution largely to the former use made of it as a herb, endowed with various healing properties. To-day it is to be found on the outskirts of almost every village or town, and very often near isolated houses of some age. It is a common plant on waste ground, and is exceedingly rare far from a building of some description. The first Greek (Latinized) name refers to the leaf segments, which resemble a goat's foot.
It is an erect plant, with a round, furrowed stem, finely furrowed length-ways, and hollow, bearing branches above. The leaves above are 3-lobed, and minutely toothed; below they are stalkless, and two or three times 3-lobed, and egg-shaped with a prolonged point. The flowers are small and white, borne in wide flat umbels, with no calyx teeth, the petals unequal, the fruit flattened laterally with almost rounded seeds. Goutweed grows to a height of 2 ft. or more. The flowers are in bloom in May, June, and July. This plant is a herbaceous perennial and propagated by division of the creeping rhizomes, occurring usually in beds.
The flowers are numerous and small. The styles are slender and bent back, and the petals inbent at the point. It is visited by numerous insects - Diptera, Coleoptera, Hymenoptera, and Neuroptera.
The flowers in the primary umbels are complete, those of the second order having male florets in the middle, complete ones at the side. The fruits are flattened and aided in wind dispersal, when ripe being semidetached, and jerked to a distance by the wind or passing herds.
The fungus Protomyces macrosporus forms warts on the stem and petioles, and Puccinia aegopodii causes swellings on the stem and midrib, and Plasmopora nivea is also found upon it.
A Hymenopterous insect, Tenthredo flava, and 2 moths, Depressaria applana and Chauliodus illigerellus, feed upon it.
Photo. J. H. Crabtree - Goutweed (Aegopodium Podagraria, L.)