Complex sentence: More innocently, Vertumnus could not woo Pomona in his own shape, but, having taken the form of an old woman, was able to gain access to her orchard and persuade her to marry him.
Split into simpler sentences: More innocently, Vertumnus could not woo Pomona in his own shape. Taking the form of an old woman, Vertumnus, was able to gain access to her orchard and persuade her to marry him.