I have been given an excerpt (chapter 1) of Novalis's romance Heinrich von Ofterdingen to read. I have to write a paper on it for my philosophy class in which I am to outline the meaning of the blue flower and my thoughts on what it is that Novalis was trying to relay to me, and connect Heinrich von Ofterdingen to other similar philosophers.

Novalis (Friedrich von Hardenberg ) was a German poet, theorist, and philosopher who greatly influenced Romanticism. He studied law in university and became familiar with the philosophical movements and ideas of Immanuel Kant and Johann Gottlieb Fichte, inspiring him to write his own case studies and academic texts where he manifested an idealistic philosophical system. He is most recognized, however, by his poetic work: Hymnen an die Nacht (“Hymns to the Night”), Blütenstaub (“Pollen”), and Glauben und Liebe (“Faith and Love”) are among his most famed writings, where he attempts to merge poetry, philosophy, and science into one and, with it, metaphorically describe the world in which we live.
His mythical romance Heinrich von Ofterdingen, which remains unfinished, tells the story of a young minstrel in the Middle Ages who, after the loss of his beloved, finds comfort again in his adventurous and romantic quest for hope and harmony. It is sometimes argued that the novel is a bold poetic response to Goethe’s Wilhelm Meister's Apprenticeship, which Novalis thought of as too realistic and bourgeois. In the story, Novalis presents the titled hero as a man on a mission to defeat his grief and despair and find happiness, peace, and tranquility. At the very beginning, Heinrich’s father describes a flower he saw in his dream:

“Among the flowers there was one that particularly pleased me, and to which all the others seemed to do homage."
"Dear father," eagerly exclaimed Henry, "do tell me its color."
"I cannot recollect it, though it was so fixed in my mind at the time."
"Was it not blue?"
"Perhaps it was," continued the old man, without giving heed to the peculiar vehemence of his son. "All I recollect is, that my feelings were so wrought up, that for a time I forgot all about my guide.”

This fascinates Heinrich, and he himself wishes to witness the flower’s wonder and beauty, and so he goes on a journey to find it. The blue flower thus becomes a symbol for all that is beautiful, magical, and wonderful; cosmic and unattainable. Consequentially, it also became a central symbol used and popularized in Romanticism, both in art and literature, where it represents a connection between humans, their emotions, and nature, as well as a journey for finding one’s self, finding love, and individualism. These motifs are, in fact, some of the most recognizable themes in Romantic works, and so it could be asserted that Novalis’s Heinrich von Ofterdingen is one of the key writings that inspired the Romantic movement.
https://www.britannica.com/biography/Novalis