goosefoot, wild spinach
藜 centers on a specific plant: goosefoot, a leafy weed also known as wild spinach. The meanings are direct botanical references rather than abstract concepts.
藜 combines the plant radical 艹 with 黎, which likely provides the sound. The character refers to a specific plant, but the exact historical development of the 黎 component is uncertain.
The grass top 艹 sits above 黎, which looks like a dense, tangled plant. Picture a weedy goosefoot plant with a thick, dark lower stalk and leafy top.
For レイ, imagine a ray of sunlight hitting the wild spinach: ray -> レイ, and the goosefoot plant soaks up the light.