Gouache is a type of watercolour paint that is more solid and opaque than traditional watercolours (Singer Sargent, of those related to the impressionist movement, produced the finest watercolour paintings). The use of gouache and pastel definitely suits Monet's style, as he frequently opted for vivid and very rich and solid colours in his works of art.
Indeed, when applying oil paints he tended to apply them straight to the canvas without mixing them and mollifying the colour and this gave his works a very bold effect. This richness of colour is one of the main hallmarks of the Impressionist style - a style which Monet developed and perfected throughout his life.
The Meadow Lined with Trees depicts, as its title suggests, a meadow with a line of trees in it. Moving crookedly across the centre of the work, the eponymous trees look almost spooky with their vibrant black limbs. Below the trees, the viewer can readily make out a cluster of rustic cottages, and this interest in the natural beauty of the French countryside and the man made structures within it is typical both of Claude Monet's work and of Impressionism in general.
Though it is clear what The Meadow Lined with Trees depicts, and though it may even be possible for the viewer to locate the exact spot where Monet was standing when he painted The Meadow Lined with Trees, it can be argued that this painting is an Impressionist rather than a realist work.
Unlike realist works of art which aim to present the viewer with a depiction of objective reality, Impressionist works aim to capture an emotion or a feeling, often one that is fleeting or evanescent. This feeling might belong to the artist, and thus an Impressionist work might be a way for the artist to communicate their feelings at a particular moment in time as they drink in a particular landscape.
But, the feeling could also be a specific one that is to be provoked in the viewer. The feelings experienced when one looks at The Meadow Lined with Trees are many - they could include foreboding, tranquility, joy, and sombre nostalgia.
When discussing Impressionism it is also worthwhile making a comparison between music and art. Impressionism in terms of musical style is one that privileges harmony of tone over clarity, to create an oneiric effect. This idea can also be applied to works of visual art such as The Meadow Lined with Trees.
Here, the wavy lines used by Monet sacrifice absolute stark, realist clarity in favour of bringing out the careful harmony that he has created in the tones that he has used. Blues, whites, and luscious greens all work together in harmony with the fluffy white of the clouds to make the viewer feel that they are placed right within the landscape and experiencing the emotions associated with it almost as strongly as if they were breathing in the fresh rural air for themselves.