Nesaea

Abstract: project (ESSER & al., 2009), we are attempting to document and account for all Euphorbia L. names and their phylogenetic placement in the genus. Euphorbia sect. Anisophyllum Roep. (the former genus Chamaesyce Gray) consists mainly of small, prostrate herbs with opposite leaves and tiny flower-like cyathia. It is occasionally confused with taxa in other families that bear a superficial resemblance to it, most notably with certain Lythraceae. Recently, BERRY & PHILLIPSON (2011) demonstrated that a species described as Euphorbia benoistii Leandri (LEANDRI, 1947) was in reality a species of the endemic Madagascan Lythraceae genus Capuronia Lourteig. Here we document a second instance in which both BAILLON (1886) and LEANDRI (1947) were fooled into recognizing a Euphorbia, E. hildebrandtii Baill., that was in reality a member of the Lythraceae. Since this name was published before a corresponding name was available in Lythraceae, it now requires a new name for the species of Nesaea Kunth under which it was published. We establish the new combination below.

Abstract: Three species of the primarily African genus Nesaea occur in the New World. One, N. palmeri, is described as new. The presence of the genus in North America has been obscured by its rarity and by an erroneous placement of the most widely distributed species, N. longipes, in the closely related genus Heimia. Morphological comparisons of Nesaea, Heimia, and Decodon-genera once included in Nesaea-confirm the distinctiveness of these genera and the correct placement of N. longipes. Nesaea consists of approximately 45 species, three-fourths of which are restricted to Africa and Madagascar. The remainder occur in Africa, southern Asia, the East Indies, Australia, and North America. Three species of Nesaea are now known from the New World, where their presence has been obscured by their rarity and by erroneous placement of the most widely distributed American species, N. longipes A. Gray, in the closely related genus Heimia. Heimia longipes (A. Gray) Cory is a gypsophilous, calciphilous species of New Mexico, Texas, and adjacent Coahuila, Mexico. It differs conspicuously in habit and morphology from the other two species of this genus. Heimia longipes is a sprawling herbaceous perennial with pink to purple petals. Heimia salicifolia Link and H. myrtifolia Chamisso & Schlectendal are shrubs to three meters tall with yellow-petaled flowers. Although herbaceous and shrubby species occur within other genera of the Lythraceae, no genera are known in the family that have purpleand yellow-petaled species. The differences in pollen morphology of H. longipes, H. salicifolia, and H. myrtifolia are equally striking. It was, in fact, the anomalous pollen of H. longipes that precipitated this study. The pollen of H. longipes is unlike that of the other species of Heimia but is characteristic of that of Nesaea. Since all the genera of Lythraceae probably have a distinctive pollen morphology, H. Iongipes appears, on the basis of pollen characters as well as floral and vegetative features, to be misassigned. Originally Nesaea also included Heimia, Decodon, and Diplusodon. Heimia and Decodon were retained within Nesaea as subgenera or sections 1 J thank Alan Graham for assistance in preparation and interpretation of the pollen; Joan Nowicke for Fig. 1-3, 6, and 7; J. Rzedowski, D. Ott, F. Potter, B. Tiffney, J. Timmerman, M. Johnston, and D. Pinkava for advice; the Department of Polymer Science, University of Akron, for use of SEM facilities; Lynn Miller for the drawings; and Marshall Johnston for reviewing the manuscript. 2 c/o Alan Graham, Biological Sciences, Kent State University, Kent OH 44242. This content downloaded from 40.77.167.32 on Sun, 04 Sep 2016 04:45:14 UTC All use subject to http://about.jstor.org/terms 62 SYSTEMATIC BOTANY [Volume 2

Abstract: Crenea Aubl. (Lythraceae) is a ditypic genus of subshrubs occurring in mangrove vegetation on the coasts of northern South America. Phylogenetic analyses based on morphology have offered unresolved and conflicting phylogenetic positions for the genus in the family. This study presents the first molecular sequences for Crenea, from nrITS, rbcL, trnL, trnL-F, and matK regions. Molecular phylogenetic analyses find full support for Crenea within Ammannia L., a relationship not previously recognized. Ammannia is a globally distributed genus of terrestrial to amphibious herbs mostly occurring in freshwater marshes and wetlands. It was recently reconfigured based on phylogenetic evidence to include the genera Nesaea Comm. ex Kunth and Hionanthera A. Fern. & Diniz. The transfer of Crenea to Ammannia further extends the morphological, ecological, and biogeographical diversity of Ammannia and provides the final evidence defining Ammannia as a monophyletic lineage of the Lythraceae. A revised circumscription of Ammannia s.l. adds several new morphological character states and the first species in the genus restricted to mangrove vegetation. Two changes in taxonomic status are made: Ammannia maritima (Aubl.) S. A. Graham, P. W. Inglis, & T. B. Cavalc., comb. nov., and Ammannia patentinervius (Koehne) S. A. Graham, P. W. Inglis, & T. B. Cavalc., comb. nov. The new combinations are described, a list of exsiccatae examined is provided, and the effects of the reconfiguration to the morphology and biogeography of the genus are detailed.

Abstract: Karyomorphology in two African species of Nesaea (N. aspera and N. cordata) of Lythraceae was studied for the first time using meristematic cells of root tips. Chromosome numbers are 2n = 10 in Nesaea