A new species of Deamia (Cactaceae) from Nicaragua Author Hammel, Barry Missouri Botanical Garden, 4344 Shaw Blvd., St. Louis, Missouri 63110 U. S. A. Author Arias, Salvador 0000-0002-7674-7050 Jardín Botánico, Instituto de Biología, Universidad Nacional Autónoma de México, 04510 México D. F., México sarias @ ib. unam. mx; https: // orcid. org / 0000 - 0002 - 7674 - 7050 sarias@ib.unam.mx text Phytotaxa 2022 2022-12-20 576 2 220 226 http://dx.doi.org/10.11646/phytotaxa.576.2.8 journal article 53507 10.11646/phytotaxa.576.2.8 e6fb33da-dd97-4631-b047-c31f8359efd8 1179-3163 7461375 Key to the species of Deamia 1. Stems 0.6–2 cm in diameter, the ribs (6–)7 or 8, acute or rounded; flowers longistylous .................................................................2 - Stems 2.5–15 cm in diameter, the ribs 3–10, acute; flowers longistylous or brevistylous.................................................................3 2. Spines up to 1.4 cm long; stem ribs rounded; flowers 8–10 cm long ............................................................................ Deamia funis - Spines up to 2.6 cm long; stem ribs acute; flowers (23–) 27–30 cm long ........................................................... Deamia montalvoae 3. Flowers 6–9 cm long, brevistylous with the stamens 0.4–0.5 cm long and the style 2–2.1 cm long, the stigma positioned well below the level of anthers; stems 2.5–3.5 cm in diameter ............................................................................................ Deamia chontalensis - Flowers 22–28 cm long, longistylous with the stamens 9–20 cm long and the style 22–24 cm long, the stigma positioned among or just beyond the anthers; stems 3–15 cm in diameter.............................................................................................. Deamia testudo