族 (zoku) n,n-suf. - tribe; race; group
I'll grant you, this is rather an odd one. It wouldn't have come up, except that I was reading a story by Doug Giles where he referred to the "heterosexual tribe". Now, that one doesn't have an attached term in Japanese as far as I know, but Giles was using it in relation to homosexual men, for whom a term has been coined: 薔薇族 (barazoku), the rose tribe. (For the sake of completion, the term for homosexual women is 百合族 (yurizoku), the lily tribe.)
Until and unless someone can show me that the Japanese have already coined another flower tribe term for heterosexuals, I'm banking for the 菖蒲族 (ayamezoku)... The iris tribe. Why? Well, beyond the fact that it's a nice-looking flower(link goes to GIS), it's the favored flower of Narumi Kiyotaka in "Spiral ~Suiri no Kizuna~". In other words, I'm being influenced by what I'm reading again.
As to why I know all this (and you're getting this one as a bonus), chalk it up to this word:
豆知識 (mamechishiki) n. - trivia; bits of knowledge (lit. - bean knowledge)