Observations of Blossfeldia liliputana (Cactaceae) populations in Jujuy province (Argentina)

Introduction. Blossfeldia liliputana Werdermann (Cactaceae) is known as the tiniest cactus with a distribution from southern Bolivia and to mid-west Argentina. Due to the inconspicuous habitus, little was known about the environmental effects on its distribution. The main objectives of this study were to describe the distribution of B. liliputana in Jujuy province, north-western Argentina, and to identify abiotic and biotic environmental parameters affecting the numerical abundance of B. liliputana populations.

Material and methods. Using existing information about ecology and previously described growth sites, we localized populations of B. liliputana and counted the number of above ground stems (hereinafter referred as “heads”) within plots of 10cm². A set of environmental data was derived from direct measurements, laboratory analysis and literature. Descriptive and multivariate statistics were used to infer habitat requirements.

Results. We found seven locations with B. liliputana populations at Jujuy. Average populations size per plot ranged from four to 22 heads. B. liliputana prefers shaded rock crevices made of shale and slates and a annual mean temperature below 14°C and a annual precipitation lower than 200 mm. Seed dispersal by ants was not observed.

Discussion. Although even after extensive field survey as much as seven locations were found, the cactus is not scarcely distributed rather the habitat is located in hardly accessible areas. Our findings suggest that B. liliputana is a habitat specialist adapted to extreme environments.