Yeah, I, too, thought so initially, but the lower component inside yamaidare is 面, not 肉. It's the same also for the hand-written one. You can see a horizontal line right under 付, which 肉 doesn't have.
The single kanji 菜 doesn't mean "rape seed", as in the dictionary you linked. It refers to "edible herbaceous plants" in general. As you can see in the explanation about the etymology of オナモミ I linked in my previous post, 菜揉み means "rubbing the plant including stalks and leaves", and ナモミ is named from this action (茎葉を揉んでつけると虫刺されに効くためナモミ（菜揉み）の名がついた). My interpretation "rape seed" is possible when with 籾, but note that 菜籾 is just my wild guess. 籾, i.e. "husk/hull" is usually not used for "rape seed". The most common word for "rape seed oil" is 菜種油, since 菜種 means "rape seed" as a compound word.