Spurges
The family Euphorbiaceae contains a number of familiar species, including the spurges, dog's mercuries and Castor-oil-plant - the latter grown as a garden ornamental. A large chunk of the family is taken up with the spurges (Euphorbia), a variable group of plants but which are easily recognised by their milky sap and very distinctive flowers. The spurges mostly have green or yellowish-green flowers surrounded by leaf-like bracts and that are made up of an intriguing and highly distinctive cluster of parts. These parts typically include a female flower and a small cluster (typically 2-4) of male flowers. These flowers sit atop a small structure (technically called a cyathium) which also carries a ring of yellowish or reddish, often glistening, glands. The glands are more or less semi-circular in outline, but the outer tips of the semi-circles are often drawn out into a pair of narrow extensions like little cow horns. After pollination, the stalked, female ovary elongates and becomes an enlarged seed capsule.
The main purpose of this page is to attempt to break this family up into manageable groups, so that the pages you are led to do not get too big by containing a large number of species. At worst, if you follow a link from here and do not see your plant, return to this page and try another link.
Be sure to read the texts below carefully, as they contain identification information that may not be visible in the photographs; clicking to the next stage will help you get to the exact species. The growth style is most important to study at this stage, to determine whether you have a small, branching annual of open ground, a multi-stemmed, upright perennial species or a creeping plant that forms a small mat of leafy branches.
Use the photos below to narrow your search to a group, then click on the picture to go to the next stage.
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Creeping Spurges These spurges have a very distinctive look as they form creeping mats of flat, horizontal branches that spread from a central stem. They are annual and rare in our area but will mostly likely be found as weeds on disturbed ground, pavements or gravel areas in urban places. Unlike the more upright spurges, the flowers of this group tend to be white rather than yellow or green and often have reddish spots. |
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Annual Spurges Plants in this group are typically rather small (less than 30cm in height on average) and have a single, slender, basal stem that branches freely. The leaves may be long and narrow or short and broad. Flowers are typically carried in open, many branched heads at the ends of the stems. These are small, annual species that tpyically grow on disturbed ground on gardens, allotments and arable fields as well as weeds of paths and roadsides. |
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Perennial Spurges Plants in this group tend to have upright, often unbranched stems with whorls of leaves. The leaves are much longer than wide, often very narrow and linear but sometimes broader. Flowers are typically carried in branched heads at the top of the stems. Some species are only biennial, producing leafy stems in the first year then flowering and setting seed from these stems in the second year. Many of the species have creeping roots and form colonies of stems in gradually spreading patches. These are mostly plants of established habitats in grassy places and woodlands (Sea Spurge is an exception, growing on open beaches). |