Clarification of Orthosia stipitata and the Description of Two New Species of Orthosia (Apocynaceae, Asclepiadoideae)

W. D. Stevens

doi:10.3417/20261024

W. D. Stevens Missouri Botanical Garden

DOI: https://doi.org/10.3417/20261024

Keywords: Apocynaceae, endemic species, Mexico, Orthosia

Abstract

Two new species, Orthosia tubularis W. D. Stevens and O. campanulata W. D. Stevens (Apocynaceae), are segregated from O. stipitata W. D. Stevens sensu Liede-Schumann and Meve (2024). These three species, along with O. ramosa W. D. Stevens and O. nubicola (Morillo) Liede & Meve, share stipitate gynostegia having gibbous anther backs and relatively long corollas enclosing or nearly enclosing the gynostegium. Each species has a narrow distribution, and as a group are native to mountains (1600–3300 m) ranging from Veracruz, Mexico, to Venezuela.