Pontes R. C., de Oliveira Deble A. S., Deble L. P., Frailea erythracantha (Cactaceae): a new species from Pampa Grasslands, Rio Grande do Sul State, Brazil, Phytotaxa, 2018, 369(3):211-218, doi: 10.11646/phytotaxa.369.3.4
Original description of Frailea erythracantha based on field surveys, herbarium specimens and cultivated plants. It includes morphology, seed micromorphology, phenology, basalt-outcrop habitat and the authors’ threat assessment of the two populations known at that time.