Understanding Vocabulary in Context: Poignant

In the following excerpt from a 19th-century novel, the protagonist reflects on the surroundings of their childhood home:

"The once-vibrant garden now lay in disarray, the once-lush foliage wilting under the oppressive heat of the sun. A few hardy flowers clung to life, their colors muted, as if they had shunned the brightness of their former selves. In that melancholic atmosphere, one could almost hear the whispers of the past echoing through the decaying trellis, a poignant reminder of joy replaced by desolation."

In this context, what does the word 'poignant' most nearly mean?