Cryptic

[Daij]

2d Ferments stem from a plant (4)
?E?N
18a Doom to Hell and motorway madness (4)
?A?N
17d Collectively, like elbows, say? (7)
???N?L?
23d It's a long time to dish out adhesion! (4)
A???
16d Flower to eat up in style (7)
P??????
13d Flight technicians who urged the Crown to change (6,4)
G?O??? , ????

Thanks in advance

[bookbinder]

2d fern

[Tilly2]

Q8 damn

[Tilly2]

^18a^

[MargoTester]

23 aeon

[MargoTester]

13 ground crew

[MargoTester]

16 petunia

[Tilly2]

13d ground staff

[nescio]

17d jointly
16d petunia
13d ground crew

[MargoTester]

17 jointly

[Daij]

One more, if I may,
Unable, say, to produce false piety (4)
C?N?
Looks like it could be 'Can't' but can't parse

[elliemay1]

cant is another word for false piety

[Daij]

Many thanks for your help

[elliemay1]

//Synonyms of cant
1
: the expression or repetition of conventional or trite opinions or sentiments
especially : the insincere use of pious words
the cant of hypocrites//

[nescio]

leave the apostrophe out - the answer is "cant"

[MargoTester]

Cant - sanctimonious religious talk