The Genus Echinocactus comprises four or five species of mainly large barrel cacti. They are found from southern USA to Northern Mexico.E. horizonthalonius is the exception in size as it grows to only up to 45cm tall and 20cm wide.
The distribution of this cactus is vast. From Texas, Arizona (var. nicholii) and New Mexico in the USA to Coahuila, Nuevo Leon,
Tamaulipas, and San Luis Potosi in Mexico.It is usually found in sandy limestone soil and can be either half buried with only the top part showing or fully exposed.
It is a slow growing plant and may live up to 60 years. Flowers are produced from the apex and are lilac in colour with a deeper throat (Have also been described as magenta or deep pink).
Blooms from March to May with another flowering season in September.Spine colour and shape also varies and may not come as a surprise when considering its vast range. From pink to dark brown to gray.
The top picture shows
E. horizonthalonius from near San Roberto, Nuevo Leon. These plants are small and do not grow larger than a few centimeters, although the ones shown are juvenile plants. The centre picture shows the plant growing at Estacion Marte, Coahuila and that of the bottom picture is from Piedras Blancas, Coahuila.