As per Shiva Purana, Lord Ganesha had two sons who were named as Shubh and Labh. Shubh and Labh are personification of auspiciousness and profit respectively. Shubh was the son of Goddess Riddhi and Labh was the son of Goddess Siddhi. Riddhi is mentioned as wife in Matysa purana.
In South Ganesa' concsert names are Siddhi and Buddhi. This as per Siva purana . Riddhi and Buddhi is mentioned in Matsya purana . In Melatur in a temple there is Dakhinamuthy Ganapathi and his marriage with Siddhi and Buddhi used to be organised on Ganesh chaturti day every year.
In Gnana Puranam, it has been described by Karka Maharishi that there are 108 Ganapathi sthalams . Siddhi Buddhi Arulmigu Dakshinamruthy Vinayagar temple at Melattur is considered the 81.
Here is another picture of Ganesha, a painting by Raja Ravi verma . Here he is accompained by Ashta siddhi
What are ashta (8) siddhi ( Supernatural powers)
Aṇimā: Ability to reduce one's size
Mahima: Ability to increase one's size
Garima: Ability to increase one's weight infinitely
Laghima : Ability to become lighter than the lightest
Prāpti: Ability to Obtain anything
Prākāmya: Ability to acquire anything desired
Iṣiṭva: Lordship over creation
Vaśitva: Having control over things