そば soba will often be 蕎麦 and is as such not infrequent. But for some reason its spelling slipped from my memory. An attempt at a mnemonic (explanation below).
蕎 soba is as long as the grass 艸 stands 高い. Since buckwheat does not contain gluten, you won't need to walk bend over 夭, holding your (fat?) painful belly.
蕎 consists of grass 艸 140 and a mixture of slumped person 夭 and tall, high 高.
夭 is referenced in Wieger 61B
Yao1. A man who bends the head forward, in order to run, to jump, to march. By extension, to lean, to incline, to hang, to rock, to shake. - Phonetic series 92. On the top of the compounds, 夭 sometimes becomes 土 in the modern writing (as 大, L. 60, fourth series), e.g; in 幸 hsing4 L. 102, and 走 tsou3 L112, 喬 ch'iao2 L. 75B. - Note 笑 hsiao4, to laugh. Etymologically, 竹 bamboos 夭 rocked by the wind; 竹得风, 如人之笑也。从竹, 从夭, 会意。 The spasmodic motion of the belly, when a fat Chinese is laughing.
The first part is confirmed in Henshell 297 ("a figure 大 with a slumped head").
喬 Wieger 75B:
ch'iao2. In this character, it was the top 亠 of 高 that disappeared, to make room for 夭 Yao1, L 61 G; 高而曲也。从天、从高省、會意。 Something 高 high, a tree for instance, the top of which bends down, overhangs. - Phonetic series 670. K'ang-hsi wrongly classified this character under 口 the mouth.
In Schuessler 蕎 is not listed as a cognate under 喬 (as opposed to 僑, 鐈, 憍 (jiāo, jiǎo) and 嶠 (jiào). I don't know how significant that is, but it seems very possible that 喬 was simply loaned for it's sound without 蕎 being related.
As of yet 蕎 is not yet listed in KANJIDAMAGE (and since noodles is the only word that it seems to be actively used for, perhaps never). BTW it seems soba is short for sobamugi, which is also written 蕎麦 (funny). 語源由来辞典
Lets try this: 蕎 soba is as long as the grass 艸 stands 高い. Since buckwheat does not contain gluten, you won't need to walk bend over 夭, holding your (fat?) painful belly.
Of course there's 麦 in 蕎麦 as well. As it happens 麦 is in KANJIDAMAGE but I don't like its entry for 麦 because I know too well that the top of 麦 is a pictographic simplification of a plant and unrelated to 主 nushi (master). For now I settle for that 麦 is more pictographic and easier to associate with the plant it stands for (but I could say that 麦 is plant 生 with a foot 夂).