Identification key to Hippeastrum from Corrientes, Argentina 1. Flowers light yellow. Perigone trumpet-shaped with a long tube (9–10 cm long). Growing in rocky slopes, between rocks and sandy soil, surrounding by xerophytic vegetation....................................................................................................... H. euryphyllum - Flowers red or orange. Perigone funnel-shaped with a short tube (2 cm long). Growing in inundated or seasonally waterlogged areas, mostly with hydromorphic vegetation.....................................................................................................................................2. 2. Flowers red. Perigone zygomorphic, tepals 1 cm wide, lower petal smaller than the upper ones. Leaves 2 cm wide, glaucous. Bulb single or with few bulblets. Growing in marshes...................................................................................................... H. angustifolium - Flowers orange. Perigone slightly zygomorphic, tepals 2.5 cm wide, lower and upper petals similar. Leaves 3.5 cm wide, dark green. Bulbs with several small bulblets. Growing in river borders ................................................................................. H. striatum

Published as part of Florentín, Javier E., Medina, Walter A., Salas, Roberto M. & Roitman, German, 2023, Hippeastrum euryphyllum (Amaryllidaceae), a microendemic species from northeastern Argentina: new combination, description, taxonomic identity and distribution, pp. 220-226 in Phytotaxa 625 (2) on page 224, DOI: 10.11646/phytotaxa.625.2.8, http://zenodo.org/record/10150406