GRASSES ARE AMAZING

They are all around us but most of us seldom think about them beyond mowing the lawn or weeding the flower bed. Because they are wind-pollinated and few have spectacular flowers, whilst others are pernicious weeds (= successful colonisers!), we tend to ignore their extraordinary ecological and evolutionary success. Some 25 million years ago, rather late in evolutionary terms, the fossil record shows that grasses became a dominant vegetation group.

I have always known the grass family as the Gramineae and we still use the adjective graminaceous when describing them in the vernacular, but they have now been renamed the Poaceae in the clade of monocotyledons (having a single seed leaf).

Grasses don’t just include the multiple species we see in our gardens, parks, and woodlands: bamboos, many of our cereals and much of our agricultural fodder are grasses. In size they range from tiny creeping forms to towering stems reaching as much as 30m in height. The Poaceae have evolved into over 10 000 different species and some remarkable features that have helped them succeed and colonise so many different habitats, including vast areas of plains, steppes and savannahs. They defend themselves against over-grazing by containing silicon dioxide and lignin which wear away the teeth of grazing animals, they grow from the base rather than the tips of shoots so they can regenerate quickly after being grazed or cut, many are exceptionally drought and cold resistant, and they are wind-pollinated so need no insect pollinators.

In the UK, we have some fifty-four genera containing about 160 species of native or naturalised grasses. Here are a few photos I have taken of just a few British grasses to illustrate the variety of this botanical family:

From top left: quaking-grass Briza media with spikes of crested dog’s-tail Cynosurus cristatus, wood melick Melica uniflora, marsh fox-tail Alopecurus pratensis, marram Ammophila arenaria, wood small-reed Calamagrostis epigejos, Yorkshire-fog Holcus lanatus, timothy Phleum pratense, floating sweet-grass Glyceria fluitans.

Betts Ecology take great care of our grassy areas which are extensive on most of our sites. We manage them to promote a healthy, species-rich sward – you can find our policy for grassland on our web site.

 © Betts Ecology