Answer:
Friendship
Step-by-step explanation:
Throughout the poem, Brontë compares two relationships using plants. When she discusses love, or the wild rose-briar, she mentions how pretty it is, but she makes sure to point out that it won't last. ("But which will bloom more constantly?" "And who will call the wild-briar fair?") When she discusses friendship, or the holly-tree, she points out how it is there for longer, even if it isn't as pretty. She sees love as fleeting yet beautiful, but she sees friendship as reliable and steady. Hope this helps!