There are two separate temples connected to Goddess Samayavaram Mariamman. Goddess Samayapuram Mariamman Temple, one of the most amongst the two is a famous Mariamman shrine in Tamilnadu. Mariamman is an aspect of Goddess Parvathi and the powers she possesses have been bestowed by Lord Siva. You will hardly find anyone who has not heard about this temple. She is family deity of many devotees who throng here from several parts of the world seeking her grace to get several desires fulfilled, get cured of long standing ailments, and protection from getting afflicted with the dreaded diseases like Small Pox or Chicken Pox which had taken several lives in the past centuries when no medication was available. People went to the temples and prayed to Goddess Mariamman seeking her grace to get cured of it early. Once the patient got cured they took them to one of the Goddess Mariamman temples and made food offerings especially meant for Goddess Mariamman. Since Goddess Samayapuram Mariamman  is considered to be the chief of Goddess Mariammans worshiped in several parts of the world under different names and appearances, people visit Goddess Samayapuram Mariamman temple too. Amman in Tamil denotes female deity and Mari refers to rain. Therefore the deity that graces like continuous rain was called i.e. Mari Amman which became Mariamman.  Amman in tamil denotes female deity.
Goddess Samayapuram Mariamman is also considered to be the aspect of Goddess Kali because any Goddess Mariamman  has fierce appearance in general. However Goddess Kali  is again an aspect of Goddess Parvathi only. Thus Goddess Samayapuram Mariamman is viewed emanation of Goddess Parvathi. Goddess Samayapuram Mariamman has been bestowed with the powers to not only bring rains but she is also considered to be the sole authority in the divine world to cure the dreaded diseases like Small Pox and Chicken Pox. The reason behind Lord Siva bestowing such powers to cure the dreaded Pox diseases to Devi Samayapuram Mariamman is connected with the Puranic legend in which when Goddess Parvathi committed suicide and her body carried away by Lord Siva. On way wherever parts of  her body fell they became Sakthi Peeda. Her eyes reportedly fell in S. Kannanur and when Samayapuram Devi Mariamman manifested as aspect of Goddess Parvathi in S. Kannanur Lord Siva bestowed her with thousand eyes and thus she  automatically got the powers to cure the Small Pox and Chicken Pox diseases as the boils of Small Pox and Chicken Pox were likened to smaller eyes of Goddess  Parvathi.

The extent of belief and fear on Goddess Samayapuram Mariamman is so deep that even by mistake if someone casually uttered that they would visit Goddess Samayapuram Mariamman temple to offer prayers for one reason or the other, without fail they would visit the temple at least once in their lifetime to offer prayer to the Goddess even if their prayer had not been fulfilled, lest it will be viewed as insult by the deity and severe problems in many forms will haunt their family or in their own life. Goddess Samayapuram Mariamman temple is located in Tamil Nadu. It is situated at a distance of 10 km from Kollidam River in Tiruchy.

The origin and history of this temple is unclear and sketchy. Several stories float on its origin, all of which are word of mouth stories only. The deity, believed to have manifested of its own in the form of clay has been reportedly worshipped by the villagers, in the same place which was jungle area several centuries ago. The general belief has been that the then unknown deity, now known as Goddess Samayapuram Mariamman has been worshipped in open area before 1000 years. The fact that the deity was Goddess Samayapuram Mariamman and manifested there thousands of years ago as an aspect of Sakthi Devi has been revealed by  Devi herself to the devotees through one of the devotees who was possessed by her in the temple festivals. Since the principal deity was of clay, another small deity carved out of stone was has been reportedly made and kept before her to which Abishekam is done and Pooja is performed to ensure the the main deity is not damaged.

The folklore mentions that much before 18th century when the temple did not exist a deity believed to be aspect of Parasakthi (they did not know that it was Goddess Mariamman) was worshipped in the temple of Sree Ranganathaswamy in Srirangam. But as the Pundit in the temple experienced severe health problems after the idol was installed and he feared that the cause of his problem was due to the deity, he ensured that the deity was removed from there and kept inside the jungle under a tree. The jungle was no other place but Samayavaram then. The locals in the Village reportedly worshipped Goddess Samayapuram Mariamman as village deity without even knowing the origin, name or other aspect of the female deity they worshipped. Those days out of fear blind belief and worship of self manifested deities were common.

The folklore further mentions that soon when the passersby and travelers felt that the deity in the jungle was protecting them  like a guardian deity, they raised a small wall like structure around the idol and converted it into a worship place. True to their belief ever since the deity began to be prayed, people  travelled fear free of robbers and animals. Much beyond protection, the villagers experienced that those who prayed to the deity found their desires getting fulfilled. Those were the days when the local deities in the villages  held sway over people.

As per another lore, the existence of the shrine inside the jungle and the immense power wielded by the deity made people believe that if satisfied with proper offerings and sacrifices she will grant the boons the devotees seek. When this belief spread, the rulers of Vijayanagaram emperors who were camping in the district of Tiruchirapalli (which was actually their army base) too reportedly came there to offer prayers and during one of their visits they made commitment to construct a temple if they won the war for which they were camping there and when turned victorious, they constructed the temple in the name of Kannanur Mariamman temple.

There is yet an other belief exist. An unnamed female deity was worshipped by the Emperors of Vijayanagaram while they were in Trichy, and when they faced defeat in the war that was going on, they began retreating from there and carried the deity too along with them. It was customary for Emperors of Vijayanagaram to carry the deity they worshipped wherever they went and camped. On way of retreat, they happened to pass through Samayapuram, which was then a jungle area and rested there for few hours. When they began to move again, the deity could not be lifted from the ground on which it was placed and therefore they had to leave it there after constructing a roofless structure around the deity which later on came to be worshipped by the travellers and passersby seeking her grace and protection. The small roofless structure was converted into a big temple for Goddess Samayapuram Mariamman by the later rulers.

One of the legends in many such stories floating state that, once during the invasion of a Muslim ruler, the idol worshipped by the locals was forcibly taken away by the invaders to break it  in their land before their King.  On way when they reached a Canal, they kept the idol and other belongings on the bank of the Canal and rested for a while to get freshened up. After taking bath in the Canal, they returned back to commence the travel, but found that the idol was missing while all other belongings were safe. Even after searching the entire area they could not find the idol and therefore the frustrated solders went away without further searching for the idol. 

Few days after the soldiers moved away, some of the villagers found the deity inside a bush surrounded by Neem trees and fearing that the deity could be powerful, they began worshiping the deity in the same place after cleaning the surroundings. No body knew how the idol went and hid into the bush. When one of the rulers named Vijayaranga Chokkanathar of Vijayanagar came to know of the greatness of the unknown deity, he constructed a temple for the goddess in Samayapuram and consecrated the idol inside the temple after realizing from his Raja guru that the deity was aspect of Parasakthi. Thus came the temple of Goddess Samayapuram Mariamman says the devotees. Many such stories are floating on the origin of the temple. However one thing became clear from all such stories that the temple for Goddess Samayapuram Mariamman has been established only by some  Emperor  belonging to the Vijayanagaram Kingdom after she manifested on her own somewhere there.

Historians state that the original temple in the present place has been constructed by  an Emperor belonging to Vijayanagaram the 18th century in Kannanur. Kannanur was called in different names in different periods of time such as Kannanpuram, Vikramapuram and Mahalipuram. Historians and researches opine that after the establishment of the temple the rulers of Vijayanagar regularly worshipped this deity. 

It is stated by historians that only in the period of Vijayaraya Chakaravarthi who held the Kingdom during 1706-1732 Mariamman the temple was duly consecrated. Even though the general belief has been such, historical records or documents are not available to authenticate all these lores since in those period  of time no written  record was maintained except implanting some culverts here and there carrying some information or messages by the invading armies or the rulers themselves. 

The main deity, affectionately called as Samayapurathal or Goddess Mariamman is made of sand and clay unlike many of the traditional statues carved out of  stones or metals, and hence  no Abishekam is conducted to the main deity here, but instead both the Abishekam and Pooja are performed to the small deity called utsava murthy (Statute taken out in palanquin or temple car during festivals) sculpted out of stone and enshrined in front of it which is considered the soul of the deity since everyone believe that Goddess Samayapuram Mariamman temporarily stays in the utsava murthy to directly accept  the Abishekam and Pooja  performed.
The devotees firmly believe that the divine mother Goddess Samayapuram Mariamman bestow health, wealth and happiness as the she has assimilated the powers of twenty stars and nine Navagrahas and therefore daily worshiping  her in this temple will nullify the malefic effects of the stars and planets. Goddess Samayapuram Mariamman manifest in all her glory with a five headed snake giving shade over her head. Manifesting Red in colour, her face shines like dazzling Sun. She appears with eight arms called Ashta Bhujam (meaning eight hands) holding different weapons and articles that include a sword and a cup of vermillion in two of her hands the appearance of which can not be seen in any one of the Goddesses Mariamman consecrated in several temples. At best some Mariamman statutes enshrined in temples appear with four hands only.  One of her legs rests on the heads of three demons. 
It is believed by devotees that Goddess Samayapuram Mariamman cures malfunctioning parts of the body and hence it is a ritual to offer small metallic replicas similar in appearance to  affected parts of the body, the replicas made out of metals like silver or steel. To get cured of the part affected, the metallic replica  i.e hand like small metallic replica to cure the malfunctioning hand, i.e leg like small metallic replica to cure the malfunctioning leg etc are deposited in the donation box seeking the grace of  Goddess Samayapuram Mariamman to get cured. 
It is normal practice for devotees to undertake fast seeking grace of the Goddess. But Goddess Samayapuram Mariamman fasts for her devotees welfare. Four weeks in a year, Mother is believed to take only butter milk and paanagam (a drink made from water, cardamom and jiggery) which is offered in the form of neiviththiyam (offering of food items to distribute as prasad). No other food offering is permitted even as prasad during those four days. 
Originally the temple was under the management of the Tiruvanaikaval Temple, a popular Sakthi Devi temple in Trichy.  Later, the control was split and currently Samayapuram has been placed directly under an independent trust monitored by the Government. 
There is another interesting lore connected with Goddess Samayapuram Mariamman. While some people believe that the deity was first abandoned by the Muslim invader in the jungle area of south Kannanur (S. Kannanur), while some others claim that the deity was placed in the jungle area of south Kannanur (S. Kannanur) by the retreating Vijayanagaram rulers after their defeat in the war. Whatever be the truth, the deity thus abandoned in S. Kannanur and found in a bush  is not disputed and taken to Samayapuram three kilometers away from there and to enshrine in a temple constructed for Goddess Samayapuram Mariamman. Since the deity was originally found in S. Kannanur, a temple came up there too enshrining another idol of Goddess Mariamman treating it as mother Goddess of Samayapuram Mariamman or Goddess Adi Mariamman meaning original Mariamman. 
The history of Goddess Adi Mariamman is interesting. As per the lore, it is stated that two thousand years ago, the place was infested with thorny bushes. A shepherd while passing through this place, heard the cries of a child near the bush. As he began searching, a voice came from the bush saying that she was there. He and the people of the place went rushing to the spot to only find a ant-hill. They immediately understood that some deity in the ant-hill had informed her presence there and therefore they erected a small thatched hut like structure in the open space and began worshiping the Goddess in the Anthill as Mariamman. Any female deity found in the Ant hill (Some call it snake pit) is considered to be the family of Goddess Mariamman. 
From then on  the villagers began performing a small festival and took an idol of Goddess Mariamman in a palanquin to Kollidam River before commencing the celebrations. Once, when they were doing so, on way back they placed the palanquin under a Neem tree and rested for a while. Again when they commenced the travel and lifted the palanquin they could not lift it. One of the devotees who was possessed of the Goddess told the crowd that she was Mother to Goddess Samayapuram Mariamman and desired to stay in that place only. The devotees had to leave the Goddess remain there and began worshiping her. Hearing the greatness of the deity, one of the Kings belonging Vijayanagaram Kingdom built a small temple there (in S. Kannanur) with a handful of sand brought from the Samayapuram temple site. This temple thus came to be called as Kannanpuram Goddess Adi Mariamman temple. Devotees visiting Samayapuram to worship Goddess Samayapuram Mariamman also visit Goddess Adi Mariamman in S. Kannanur temple to offer prayers considering her to the Mother Goddess of Samayapuram Mariamman. Even this day in the annual festival of Goddess Samayapuram Mariamman, it is stated that the Urchava Murthy of Goddess Samayapuram Mariamman on palanquin is customarily taken to Goddess Adi Mariamman temple and brought back to enable both daughter and mother meet each other for some time.  
As per the belief while  Devi Samayapuram Mariamman manifested 1000 years ago, her so called mother Goddess Adi Mariamman reportedly manifested two thousand years in the place where her temple exist.