(Udo no taiboku; “A large udo tree”)
Of a person, big but good for nothing. An udo plant can grow up to about two meters tall and as thick as some trees, but its flesh isn’t strong or hard like wood (and it’s only edible as a young shoot), so it’s considered useless out of proportion to its size – and this saying is used to apply that situation specifically to a person who is physically large but not actually strong or useful. Like an executive who stands 6’2” but still couldn’t think his way out of a paper bag.
This is another simple phrase comprising two noun phrases connected by the associative particle の (no). The first noun is 独活 (udo), an herbaceous flowering plant also known as “Japanese spikenard.” The second noun is 大木 (taiboku), “large tree.”
A longer version of the phrase specifies that that large udo tree ～柱にならぬ (hashira ni naranu), “doesn’t become a pillar” – i.e. no matter how thick the stem is, it’s too weak to be used as a structural support. Keep in mind, though, that this saying can only be applied to people, not other inanimate objects or potential building materials.
(“Banjin Nanko wa shokuyoku morimori de, kinniku mo morimori ni mieru mono no senryoku wa nashi. Sonna udo no taiboku taru mono wo nakama ni ireru to, kekkyoku kiken wo okasu ni suginai to osorete orimasu.”)
[“Nanco the Barbarian has a burgeoning appetite and the appearance of burgeoning musculature, yet lacks in martial ability. I fear that for us to admit such an ineffectual behemoth into the fellowship would in the end be no more than to place ourselves at risk.”]