Guardian 26,004

[GKW]

1ac Flower from Colorado, white one in field C_ _ _ _ _ _
9ac Old king finds duck among some swans H_ _ _ _
10ac Shorten it - otherwise it's most unpleasant _ _O_ _ _ _ _ _
2dn Hawk is close to finding endless fish _ _ _ _O_G_R
3dn Dipper left in Scottish stream _ _ _ _E
4dn Exercise book found in ancient battlefield rocks science _ _ _ _O_ _ _Y

TIA

[bibblebub]

4d) PETROLOGY = P.E. + 'log' inside 'Troy'

[bibblebub]

3d) LADLE = L inside 'lade' [scottish stream]

[factor-fiction]

http://anagram-solver.net/Shorten%20it
THORNIEST

[factor-fiction]

warmonger?

[bibblebub]

2d) WARMONGER = warm + (c)onger

[factor-fiction]

Yes, 2d is WARMONGER

[bibblebub]

9a) HEROD = O inside 'herd' - a group of swans is called a herd

[bibblebub]

1a) COWSLIP = Co. + w + slip [cricket fielding position]

[GKW]

12ac Catch criminal flicking a tree creeper _ _ _ _ _
15ac They turn hummingbirds jaws without resistance O_F/_ _ _ _ _ _
22dn Crow shot inside court B_A_ _

TIA

[Ian_watts]

Liana
Off Breaks
Boast

[Ian_watts]

http://www.fifteensquared.net/2013/07/19/guardian-cryptic-n-26004-by-bonxie/ explanations here