This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 蘽 is uncertain. It visually contains 艹 (grass) and 櫐, but the original component relationships are unclear.
The top 艹 suggests a plant, and the dense lower part 櫐 looks like a tangled vine. Picture a thick, climbing vine plant.
For ルイ, imagine a vine that looks like a tangled ruin: ruin -> ルイ, and the vine grows over the ruins.