organ

bodily organs

He was thinking; but the glory of the song, the swell from the great organ, the clustered lights, […], the height and vastness of this noble fane, its antiquity and its strength—all these things seemed to have their part as causes of the thrilling emotion that accompanied his thoughts.

If the Snake has an unmistakeable resemblance to the male organ in its active state, the foliage of the tree or bush is equally remindful of the female.