If, like me, you need the help of an expert to identify the more unusual plants when you’re out enjoying the countryside, then try the New Holland Concise Wild Flower Guide published in association with The Wildlife Trusts. This handy little book is full of coloured illustrations showing the all-important features of flowers, leaves and the way that plants grow.

I took this pocket companion with me to BBOWT’s Hartslock Nature Reserve, near Goring, where I spotted sweet violets sprinkled across the grassland, their little mauve flowers prominent among the wintry grasses.

Looking closer at the ground where rabbits had nibbled, I could see the tiny green leaves of wild thyme forming a mat of foliage against which the pinky-purple flowers will bloom from June. Seed heads of last years’ marjoram and scabious were nodding in the breeze, promising more blue-ish, mauve flowers to come.

Chiltern wild flowers I was too early to see the elusive pasqueflower, a noted rarity in the chalk grassland of Hartslock. This is another mauve or purple flower that thrives on the poor, thin soil covering the dense chalk. During April the upward-facing bell-shaped flowers can be seen easily.

This is one of the more unusual plants of the Chilterns that features on the BBOWT website www.bbowt.org.uk Hartslock nature reserve is renowned for the deep pink and white lady orchids and the lighter pink and white monkey orchids that have repopulated the steeper west- and south-facing slopes. When BBOWT took over the site in 1975 there were just seven monkey orchid plants, and last year more than 400 lady and monkey orchids were recorded.

As part of the Wildlife Trust’s Chilterns Chalk Grassland project, the most sensitive areas where the orchids are known to flourish are fenced off to protect the plants from being eaten by rabbits and prevent enthusiastic visitors from trampling them. The first hybrid plant of the monkey and lady orchid was found there in 2006, and since then Hartslock has attracted many visitors. The new hybrid has flourished, and nearly 300 plants were counted in 2011.

Diverse habitats Another BBOWT nature reserve where it’s useful to have the Concise Wild Flower Guide with you is Sydlings Copse, between Barton and Stanton St John. This is an unusual reserve with wet woodland, sandy heathland and grassy meadows all within a few hundred metres of each other, so it’s helpful to have a guide to identify flowers in each habitat, and you’ll find the pungent ramsons or wild garlic here. If you’re still wondering about the distinctions between primroses and cowslips take a look at these two photos.

Primroses flourish in grassland and woodland, their petals of soft yellow facing up from the mat of leaves. In contrast, their cousins the cowslips have tube-shaped darker yellow flowers in clusters at the top of stems. You can see these and many other wild flowers on a guided walk at Chimney Meadows nature reserve, near Bampton, on Sunday, April 15.

To find out more about wild flowers and other wildlife on BBOWT nature reserves go to www.bbowt.org.uk. Visit the What’s On pages to find guided walks on reserves and other notable wildlife sites to spot butterflies, birds and wild flowers.