Ground ivy is a common woodland plant but will grow in somewhat more open areas. It is not related to Ivy, it just grows in a similar way ie creeping along the ground. However it does not grow up vertical surfaces such as tee trunks and walls as will Ivy. It is in fact part of the large Lamiaceae family formerly known as the Labiates which includes all the nettles.
As such it has the typical Labiate characteristics such as stems which are square in cross section and the typical nettle flower shape, a tube of 5 fused petals with the lower pair of petals sticking out as a lip. The flowers are a purple blue colour and flower from quite early in the year (March/April) but then keep going for several months. Individually the flowers are fairly small but as the plant can produce quite a lot then effectively it will produce quite an impressive display.
The leaves are not ivy shaped they are a rounded kidney shaped and have crenulated edges, they are also quite soft and covered with fine hairs. This plant has various reactions to the amount of light it is growing in. If the light is on the bright side the the leaves will be quite small and will often develop a purple colour. This coluration can just be seen developing in the upper leaves in the photo above. The reason for this pigmentation is to protect the photosynthetic pigments of chlorophyll which can become photoxidised (break down) if the light is too intense.
If there is insufficient light available the leaves will grow much bigger and obviously they will have no need to produce the purple secondary pigments and in fact the leaves will produce more chlorophyll than normal and thus look a darker green. Another clever little trick that ground ivy has up its sleeve is to produce longer inter-nodal sections in dark conditions. ie the distance between one pair of leaves on the stem to the next pair of leaves is much greater. The ‘thinking’ behind this is that if the amount of light being received is sufficient then you want to stay in that area, so keep the inter-nodal distance short and you will not inadvertently grow into a less well light region. If on the other hand light is a problem then make your stem growth longer and you will be more likely to grow into a more conducive area. Incidentally the plant has the abillity to produce roots at each node so as it grows it send down new roots to establish and maintain itself. It is a bit like predators searching for prey, if there are lots of rabbits in one area then Mr Fox does not have to travel too far to catch his dinner. If the population is low and thinly spread then he will have to increase his hunting range in order to get sufficient food.
Ground Ivy is a perennial and is native to Europe but has been spread all over the world. It will reproduce asexually as explained above but it also produces seeds and can be spread in that way as well.
If you crush the leaves they produce a ‘pleasant’? smell, well its OK, quite distinctive and definately not unpleasant It can be used to make a tea and there are lots of references to adding it into salads and that it has various medicinal uses. However you generally see the advice to eat it or use it sparingly as it contains lots of different chemicals some of which may be harmful in larger quantities. One interesting use is that it can cause milk to set and is thus an alternative to rennet and so can be used to produce cheese suitable for vegetarians. Although why a vegetarian will eat cheese but not beef I can’t understand unless it is simply a matter of taste and not on any moral considerations.
It was also used years ago to flavour beer before hops were extensively used. This was called Gruit and various herbs were used to flavour it. Gruit was a combination of herbs, commonly including sweet gale (Myrica gale), mugwort (Artemisia vulgaris), yarrow (Achillea millefolium), ground ivy (Glechoma hederacea), horehound (Marrubium vulgare), and heather (Calluna vulgaris). Strictly the word ale means a brew flavoured with herbs such as Ground Ivy whereas Beer is a brew flavoured with hops. The decline of Gruit ale was not just to do with the increase of hopped beer but also it did not accord with the Catholic church. It was said to be ”highly intoxicating and an aphrodisiac when consumed in sufficient quantity. It was supposed to stimulate the mind, create euphoria, and enhance sexual drive.” Recently with the increase of ‘craft’ beers there has been a minor recovery in the production of Gruit Ales. For more info on specialist ales including Gruit click Growlermag home brew Photo of beer is from wikipedia….thanks
Click to see other flowers from the Wye valley woodlands