I always look forward to - and love - the bank holiday specials, a welcome change of pace from the usual fare in the prize slot. Clearly, knowledge of the theme will affect levels of enjoyment (botanical themes my personal blind spot), but it would hardly be fair to criticise a puzzle because its theme didn’t ring your bell. I particularly enjoyed this puzzle. The theme is accessible, but I would say the unnumbered answers are roughly 50-50 when it comes to well known to me vs before/after “my time”. Only one of the first type was completely unknown to me, but once the first anagram of each pair had been unraveled the other usually yielded at worst to a reasonable guess. Apart from 23a, obviously, which came up when I checked its pair (the one I’d never heard of) on Google. Oh well, I’m sure things like Google are now factored in by the setters for some of their more unfair clues/solutions. Sometimes when you click re the theme of these specials, the others fall all too easily, but here I found I got the theme quite early, but the last of the special clues held out for almost the duration of solving time. Pretty much perfect I would say
Anyway, a long way of saying I thought this was great. Only quibble is 17a. Am I right in thinking it is not really a cryptic clue at all? Or am I missing something subtler?