The Scaly Tree Ferns Allied to Cyathea multiflora (Cyatheaceae) in Colombia and Neighboring Countries

Abstract. We present an update to our knowledge of the taxonomically challenging Cyathea multiflora-group. Several taxa can be reinstated and newly described thanks to extensive field studies in Colombia and bordering countries. Easily overlooked characters like minute hairs, laminar squamules, and size of indusia correlate with distinct physiognomies in the field. Cyathea multiflora in the strict sense is almost restricted to Mesoamerica, just reaching into the Colombian Darién region. We observe a geographic overlap of several species especially in the Darién-Chocó region (Cyathea hildegardis sp. nov., C. pinnula, C. pinnuloides sp. nov., C. retanae) and two wider-ranging species extending from Mesoamerica into the Andes (C. acutidens, C. pinnula). The reinstated C. columbiana and newly recognized C. uregoana sp. nov. and C. prosopioides sp. nov. are restricted to the Chocó, including the Ecuadorean Esmeraldas region. Frequently found in the northern Colombian Cordillera central is C. paisa sp. nov., which is intermediate between C. pinnuloides of the Darién-Chocó region and C. lindigii, a relatively large species widespread in the Cordillera Oriental and the eastern Andean slopes south to Bolivia. We retain C. acutidens and C. leucolepismata as distinct species that can also be readily distinguished in the field by their appearance and the shape of the entire leaves but can be difficult to differentiate as fragmentary specimens. Cyathea mariposana sp. nov., a trunkless species presumably more closely related to C. squamulosa, is described from Panama. Cyathea retanae is reported from Colombia. A lectotype is chosen for C. columbiana. All relevant species are illustrated and incorporated in a diagnostic key.