PICUMNUS is merely another form of Picus, and with him is associated his brother and double PILUMNUS. Picumnus, a rustic deity (like Picus) and husband of Pomona, is specially concerned with the manuring of the soil and hence called Sterquilinus, while Pilumnus is the inventor of the pounding of grain, so named from the pestle (pilum) used by bakers. Under a different aspect, the pair were regarded as the guardians of women in childbed and of new-born children. Before the child was taken up and formally recognized by the father, a couch was set out for them in the atrium, where their presence guarded it from all evil. Augustine (De civitate dei, vi. 9) mentions a curious custom: to protect a woman in childbed from possible violence on the part of Silvanus, the assistance of three deities was invoked Intercidona (the hewer), Pilumnus (the pounder) and Deverra (the sweeper). These deities were symbolically represented by three men who went round the house by night. One smote the threshold with an axe, another with a pestle, the third swept it with a broom three symbols of culture (for trees were hewn down with the axe, grain pounded with the pestle, and the fruits of the field swept up with the broom) which Silvanus could not endure.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)