This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 藭 is uncertain. It visually combines the grass radical 艹 with 窮, but the original semantic and phonetic roles are unclear.
The grass radical 艹 sits above 窮, a kanji associated with poverty or extremity. Imagine a rare, hard-to-find grass growing in a barren, impoverished place.
For キュウ, imagine a rare grass that makes a soft 'kyu' sound when the wind blows through it: kyu -> キュウ.