S. alsinoides'''s distribution ranges from northern Queensland in Australia north to the island of Luzon in the Philippines and southern parts of Sulawesi in New Guinea. In Australia its typical habitat has been reported as a sandy soil in swamps that are dominated by Melaleuca quinquenervia, but has also been found on creekbanks with Melaleuca leucadendra or in some of the wetter rock crevices.
S. alsinoides's distribution spans from northern Queensland in Australia north to Luzon Island in the Philippines and southern parts of Sulawesi in New Guinea. In Australia, its typical habitat has been reported as sandy soil in swamps dominated by Melaleuca quinquenervia, but it has also been found on creekbanks with Melaleuca leucadendra or in some wetter rock crevices.