Premise Counting chromosomes is a fundamental botanical technique, yet it is often intimidating and increasingly sidestepped. Once mastered, the basic protocol can be applied to a broad range of taxa and research questions. It also reveals an aspect of the plant genome that is accessible with only the most basic of resources—access to a microscope with 1000× magnification is the most limiting factor. Methods and Results Here we provide a detailed protocol for choosing, staining, and squashing angiosperm pollen mother cells. The protocol is supplemented by figures and two demonstration videos. Conclusions The protocol we provide will hopefully demystify and reinvigorate a powerful and once commonplace botanical technique that is available to researchers regardless of their location and resources.
As part of ongoing efforts to understand, document, and conserve the flora of southeastern North America, we propose two new species, the recognition of a usually synonymized variety, the acceptance of two species of Waltheria as being present in peninsular Florida, taxonomic acceptance of a sometimes deprecated species transferred with a new name into a different genus, and we clarify the distribution and ecology of a species. In Carex (Cyperaceae), we re-analyze infrataxa in Carex intumescens and recommend the recognition of two varieties, a taxonomic schema first proposed in 1893, but usually not followed in the 128 years since. In Euphorbia (Euphorbiaceae), a careful assessment of south Florida material of Euphorbia subg. Chamaesyce sect. Anisophyllum subsect. Hypericifoliae reveals the need for taxonomic changes to best classify endemic representatives of this group, resulting in the naming of a new species, and a new name at species rank in Euphorbia for a taxon first named in Chamaesyce and sometimes subsequently treated at only varietal rank in Euphorbia. Chamaecrista deeringiana (Fabaceae, subfamily Caesalpinioideae) has been repeatedly misinterpreted to include two different and disjunct population systems with differing morphologies and habitats, which are here interpreted as separate species, one newly named and the other Chamaecrista deeringiana returned to its original and narrower interpretation as a south Florida endemic. Waltheria (Malvaceae) has sometimes been interpreted as being represented in Florida by a single taxon, Waltheria indica, but we disentangle the concepts of the widespread W. indica and the West Indian W. bahamensis and clarify that both are present in the southeastern United States. We reconsider the occurrence and habitat of Toxicoscordion nuttallii (Melanthiaceae) in three states in which it has been reported as a rare species, Mississippi, Missouri, and Louisiana, and remove it from the Mississippi flora as a garbled and false report. In Louisiana, its occurrence in calcareous prairie complexes limits its potential occurrence in the state to a specialized and rare habitat, but careful exploration of habitat remnants may result in the discovery of additional populations. Taxonomic studies and re-assessments of this kind are critical in laying the best scientific foundation for regulatory, policy, and land conservation decisions. This paper names or makes the case for the renewed acceptance of six species with range-wide conservation concern: one Critically Imperiled (G1 – Euphorbia ogdenii), one Imperiled (G2 – E. hammeri), and four Vulnerable (G3 – E. garberi, E. porteriana, Chamaecrista deeringiana, C. horizontalis).
As part of ongoing efforts to understand and document the flora of the southeastern United States, we propose a number of taxonomic changes and report a distributional record. In Rhynchospora (Cyperaceae), we elevate the well-marked R. glomerata var. angusta to species rank. In Dryopteris (Dryopteridaceae), we report a state distributional record for Mississippi for D. celsa, filling a range gap. In Oenothera (Onagraceae), we continue the reassessment of the Oenothera fruticosa complex and elevate O. fruticosa var. unguiculata to species rank. In Eragrostis (Poaceae), we address typification issues. In the Trilliaceae, Trillium undulatum is transferred to Trillidium, providing a better correlation of taxonomy with our current phylogenetic understanding of the family.
As part of ongoing efforts to understand, document, and conserve the flora of the southeastern United States, we make new combinations to accord with our generic taxonomy, name a new hybrid, re-recognize a species relegated to synonymy in recent decades, lectotypify and generally clarify nomenclatural issues in several genera, clarify taxonomy and distributions of species, and report important new and current distribution records. In Doellingeria (Asteraceae), we clarify the taxonomy and distribution of D. sericocarpoides and D. umbellata in the region. In Trilisa (Asteraceae), we summarize and clarify the taxonomy, name a new hybrid, and present a new key to the taxa in the genus. Species delimitation in Stillingia (Euphorbiaceae) has been controversial and unsettled in the region, and we examine the confused taxonomy and nomenclature of the genus in the southeastern United States, re-recognizing a species used by J.K. Small, but with an expanded circumscription and a clarification of various nomenclatural issues. We examine typification of Desmodium dillenii (Fabaceae) and its application to our modern understanding of the circumscription of taxa, recommending it be considered a junior synonym of Desmodium glabellum. In Juncus, we assign a lectotype for Juncus anthelatus, fixing its application. In Primulaceae, we discuss the delineation of genera in Lysimachieae, and take a middle path regarding lumping/splitting, supporting the recognition of traditional and monophyletic segregates Trientalis, Steironema, Anagallis, and Centunculus, while treating Lysimachia in a moderately broad sense, including Glaux and multiple subclades; in order to implement this taxonomy in the southeastern United states, we make a single new combination in Steironema. We also discuss generic circumscription in Selaginellaceae, and argue for the recognition at genus rank of six major clades, monophyletic, ancient, and morphologically recognizable; in order to apply this taxonomy in the southeastern United States, we make five new combinations in Bryodesma, Gymnogynum, and Stachygynandrum. Finally, we report important new records of locally, regionally, or globally rare species in North Carolina: Helanthium tenellum, Chenopodium berlandieri var. macrocalycium, Carex barrattii, Carex vestita, Eleocharis compressa var. compressa, Rhynchospora compressa, Rhynchospora sulcata, and Croton michauxii.
Marshallia grandiflora (Asteraceae, Helenieae, Marshalliinae) is recognized as the 53rd extinct species to North America, and an endemic species of the Blue Ridge physiographic province of North Carolina. A new name, Marshallia pulchra, is provided for the more broadly ranging species that has been confounded with and generally considered conspecific with M. grandiflora. Morphologic and biogeographic data clearly separates two species within the previous concept of M. grandiflora. Marshallia grandiflora and M. pulchra are compared with their sister species, M. legrandii. Cytological data is given for M. legrandii, including the first report of B-chromosomes in the genus.
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