By far the most common sedge one will find when walking in woodland is the wood sedge (Carex sylvatica). It occurs in damp places in woodlands which are frequently alongside paths and where it occurs it can be quite abundant.
This is a relatively easy plant to identify as, being a sedge, it does not have a flower although it does have a fluorescence; pale yellow catkin-like 'spikes', similar to some grasses. It has numerous thin-pointed pale green leaves giving the whole plant a kind of 'bushy' appearance and it can grow to two feet tall but in my experience I think one foot is about the norm.
Whilst being predominant a deciduous woodland plant it does occur amongst conifers but usually where deciduous trees were once present or where there are deciduous trees close by. Being a shade loving plant it is also grown in gardens as ground cover in sheltered places.