cotton
絮 centers on cotton as a soft, fibrous material, often in a raw or wadded form.
絮 combines 糸 (thread) with 如, which likely contributes the sound. The character originally referred to raw silk floss or cotton wadding.
The top 如 looks like a woman 女 beside a mouth 口, and the bottom 糸 is thread. Picture a woman pulling soft cotton threads from her mouth to spin into yarn.
For ジョ, imagine a soft cotton robe called a 'jo' (like a Japanese じょ robe) made from the finest cotton threads.
willow flower