<p><strong>Two new species of <em>Zamia</em> (Zamiaceae, Cycadales) from the Magdalena-Urabá moist forests ecoregion of northern Colombia</strong></p>

Abstract

We describe and illustrate Zamia imbricata and Z. sinuensis, two new species (Zamiaceae, Cycadales) from the Magdalena-Urabá moist forests ecoregion of northern Colombia. The new species appear to belong to the manicata clade, an assemblage of species strongly supported by recent molecular phylogenetic analyses and which shares a set of morphological characters such as hypogeous to semi-hypogeous stems, distinctly toothed leaflets, long peduncles, megasporophylls with relatively flat shields, and diminutive pollen cones containing microsporophylls with a much-reduced fertile section of the lamina. Zamia imbricata, a species from the Middle Magdalena Valley Basin of Caldas, is distinguished from other members of the clade by its planar leaves comprised of diminutive, highly imbricate papyraceous leaflets. Zamia sinuensis, a species from the Sinú River Basin of Córdoba is similar to Z. manicata, from which it is distinguished by the absence of the petiolule and gland-like collar that characterize the latter, and by its strongly undulate leaflets. The two new species are discussed within the context of the manicata clade, and a vegetative key to the clade is provided.

Reconciling fossils with phylogenies reveals the origin and macroevolutionary processes explaining the global cycad biodiversity

“…The World Checklist of Vascular Plants (WCVP; Govaerts et al ., 2021 ) lists 362 recognized species of Cycadales. However, new cycad species are regularly described each year (Calonje et al ., 2021 ; Pérez‐Farrera et al ., 2021a , b , 2022 ; Martínez‐Domínguez et al ., 2022 ), so that there are now 370 cycad species (The World List of Cycads: http://cycadlist.org/ , Calonje et al ., 2022 ). From the WCVP data, we extracted the distribution range of each species (‘geographic_area’) to categorize their continental distribution for biogeographic analyses (to be described later).…”

Cretaceous pollen cone with three‐dimensional preservation sheds light on the morphological evolution of cycads in deep time

“…However, there are four species of Zamia with relatively small pollen cones including: Z. sinuensis Calonje & J. Castro, Z. imbricata Calonje & J. Castro, Zamia melanorrhachis D.W. Stev. and Z. hymenophyllidia D.W.Stev (Stevenson, 2004; Calonje et al ., 2021). The latter two species can have pollen cones that measure 1.0–3.0 cm in length (Stevenson, 2004); to our knowledge, these two species have the smallest pollen cones of any living cycad.…”