1: Wild rose engulfs one willow (5)
4: Speaks about actor Alan, a youth (5,4)
9: Picture a dessert without topping (3)
10: Stranger, in turn, had an accident (3-3-3)
11: Bird accompanying gangster or outlaw (5,4)
12: Prohibit an attorney's organization (3)
13: Booster involving risk brought to a halt early form of Voyager (7)
16: Trainees' ads make TV (7)
18: Observed, like hot tea? (7)
19: Appears that fine car is elevated (5,2)
20: Mann's 'Death in Venice' Dorothy sent up (3)
21: Moldering, moldering panhandler? (4,5)
24: Roll dirt and clay round tip of thumb with three fingers (9)
25: Beauty stripping top and bottom is an additional feature (3)
26: 'I was Monty's missus!', reveals old witch (9)
27: Caught carrying oregano's essence in inhalers (5)