Some similarities to : Lacecap Hydrangeas, insofar as that also has larger flowers on the periphery of the 'umbel', but Lacecap Hydrangeas are not usually white and are cultivated garden plants. Also to
Elder (Elderflower / Elderberry), but in Elder the flowers are much the same size across the pancake.
Slight resemblance to : flowers in the Umbellifers (Carrot Family) (since it has flowers in flat umbel-like clusters.
Distinguishing Feature : The three-pronged leaves together with the flat umbel of white flowers, the outer of which are much larger (and sterile) than the inner ones.
No relation to : Any Rose at all [they are merely plants with similar names]
Guelder-rose was once thought to belong in the Honeysuckle Family [Caprifoliacea], but now Taxonomists have changed their minds and think it now more properly resides in the Moschatel Family. The berries may be less toxic than was once thought.
Chemically, Guelder-rose contains the resinous greenish-yellow bitter principle and complex iridoid glycoside
Viburnin plus Valerianic Acid (aka Isobutyric Acid), α-Amyrin, β-Amyrin, Coumarins (Scopoletin and Aesculetin), Oxalates, Salicosides (being glycosides of
salicylates), Tannins and Saponins.
Many of those compounds are poisonous.
Traditionally, concoctions from the plant have been used as a smasmolytic (to relieve both voluntary and in-voluntary muscle spasms).
The berries, which are poisonous unless cooked, are translucent red and contain a sticky juice. They make a good jam, it is told. The leaves turn a brilliant scarlet in autumn.
Habitat: Dry and damp scrub, hedges and Fens.
Valerianic Acid, better known as Isobutyric Acid or 2-methylpropanoic acid, is a simple carboxylic acid or short-chain fatty acid (very short!), found in Guelder-Rose.
It is a flammable vaporous liquid and toxic irritant that will burn the skin and eyes on contact; exposure should be avoided. It has a characteristic sweet smell to those who can smell it, but about 1 in 40 of the population have a genetic disability to smell this compound. Small amounts are found in certain foods and fermented drinks.
A COUMARIN SUNBLOCKER
Aesculetin (aka Cichorigenin and Esculetin) is a derivative of Coumarin and a natural lactone found in Guelder-rose
Cinnamon and Chicory (hence the synonym Cichorigenin).
Aesculetin/Esculetin should not to be confused with Aesculin/Esculin which is the glycoside of the former.
Like Scopoletin which is also found in Guelder-rose, Aesculetin is used as a UV-blocker in suncreams, although paradoxically there is some evidence to suggest that it is photo-toxic, damaging the skin when exposed to UV!
Aesculetin also helps to prevent liver damage caused by an over-dose of Paracetamol. Aesculetin is thus anti-hepatotoxic, which may explain the folklore use of Chicory in which it also occurs for liver damage.
Aesculetin is used pharmaceutically as an anti-dysentry drug. For this purpose it is obtained from the Chinese Ash Tree (Frazinus rhychophylla) which is not native to the UK.