The difference appears to be that in the forest there is strength and thriving growth, in comparison to the wilted potted plant found in the town.
The ‘wretched geranium’ is a comparison with Sylvia when she lived in the town before going to live wither grandmother, Mrs Tilley.
Sylvia thought often with wistful compassion of a wretched geranium that belonged to a town neighbor.
The flowers in the forest are not individualized: they form a part of the woodland, and it is only the trees which are distinguished by names –
Pines and oaks and maples
The only other plants identified is the huckleberry, where Mistress Moody, the cow, likes to hide, and the birch trees.