Origin and Habitat: Uruguay, Brazil (Rio Grande do Sul)

Synonyms:
Gymnocalycium hyptiacanthum subs. uruguayense (Arechav.) Mereg.
Echinocactus uruguayensis Arechav.
Gymnocalycium uruguayense (Arechav.) Britton & Rose

Description: Gymnocalycium uruguayense is a small cactus species, usually solitary and barely rising above ground level. This species is characterized by a marked variability in the length and shape of the spines that resemble the long leg of a spider and has received many names.

Source: The Encyclopedia of Caci

Gymnocalycium uruguayense has a relatively large range, but many subpopulations throughout its range have been affected by anthropogenic pressures. A decline of 40% in the last ten years has been estimated based on direct observation and a decline in habitat quality and quantity. The threats are understood, but they are not reversible and will not cease in the near future. Hence, it is listed as Vulnerable.

Source: IUCN Red List of Threatened Species

Scientific classification

Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Cactaceae
Subfamily: Cactoideae

                         – Wikipedia.