Rubiacearum Americanarum Magna Hama Pars XLIX: Overview of the Neotropical Genus Tournefortiopsis (Guettardeae), With Some New Species and Subspecies

Guettarda L. (Rubiaceae) as traditionally circumscribed has been found to be polyphyletic in molecular analyses. Tournefortiopsis Rusby has been separated from it based on details of inflorescence arrangement, pyrene shape, and molecular analyses. We here find additional characters that distinguish this genus: valvate-induplicate corolla lobes and apical horns on the pyrenes. Some features that are usually consistent within species and often genera of Rubiaceae vary within some species of Tournefortiopsis, especially pubescence form and number of corolla lobes and locules. Our taxonomic review of this genus recognizes 12 species found in Central America and perhaps southern Mexico, the Lesser Antilles, and northern and Andean South America, and finds its center of diversity in the Andes of Colombia. Chomelia torrana C. M. Taylor is here transferred to Tournefortiopsis, and four species are newly described here plus one recently recognized variety is raised to species status, all in South America: T. crassifolia (Standl. ex Steyerm.) C. M. Taylor & A. C. Berger, T. deviana C. M. Taylor, T. robusta C. M. Taylor, T. sopkinii C. M. Taylor, and T. tamboana C. M. Taylor. Tournefortiopsis crispiflora (Vahl) Borhidi is here treated as widespread and morphologically variable, with a complex of forms that are not distinctive but completely separable and with notable diversification in Central America and the northern Andes. Four subspecies of T. crispiflora are recognized, with one circumscribed differently than previously and one newly described, T. crispiflora subsp. delicatula C. M. Taylor & A. C. Berger. The identity and characters of T. dependens (Ruiz & Pav.) Borhidi are clarified, and it is more widely distributed than previously noted. Six names are lectotypified.

New adaptive peaks for crops – an example from improvement of drought-resilience of sorghum in Ethiopia

As the center of diversity for sorghum [Sorghum bicolor (L.) Moench], elite cultivars selected in Ethiopia are of central importance to sub-Saharan food security. Despite being presumably well adapted to their center of diversity, elite Ethiopian sorghums nonetheless experience constraints to productivity, for example associated with shifting rainfall patterns associated with climate change. A sorghum backcross nested association mapping (BC-NAM) population developed by crossing thirteen diverse lines pre-identified to have various drought resilience mechanisms, with an Ethiopian elite cultivar, Teshale, was tested under three rain-fed environments in Ethiopia. 27, 15, and 15 QTLs with predominantly small additive effects were identified for days to flowering, days to maturity, and plant height, respectively. Many associations detected in this study corresponded closely to known or candidate genes or previously mapped QTLs, supporting their validity. Field tests show drought resilience to be improved by incorporation of adaptations from the diverse donor lines. The expectation that genotypes such as Teshale from near the center of diversity tend to have a history of strong balancing selection, with novel variations more likely to persist in small marginal populations, was strongly supported in that for these three traits, nearly equal numbers of alleles from the donor lines conferred increases and decreases in phenotype relative to the Teshale allele. Such rich variation provides a foundation for selection to traverse a 'valley' of reduced yield and arrive at a new 'adaptive peak', exemplifying the nature of efforts that may be necessary to adapt many crops to new climate extremes.

Touch me carefully: a step towards understanding morphological diversity in the South American spiny sunflowers (Compositae, Barnadesioideae)

The subfamily Barnadesioideae (Compositae) is endemic to South America, comprising 10 genera and 80 species of mostly spiny herbs, subshrubs, shrubs, trees, or woody vines distributed from Venezuela to Argentina. Three genera, Dasyphyllum (27 species), Chuquiraga (22 spp.) and Barnadesia (19 spp.) contain 85% of the species, while the other seven genera (Archidasyphyllum, Arnaldoa, Doniophyton, Duseniella, Fulcaldea, Huarpea, and Schlechtendalia) are represented by up to three species each. Most species are found in xeric areas in the Andean and Patagonian regions—as in the Páramos, Puna and Patagonian steppe vegetation—with a secondary center of diversity in eastern South America. Previous phylogenetic hypotheses have clarified the relationships within the subfamily, showing that there are many non-monophyletic groups in different taxonomic ranks. As a result, taxonomic changes have been proposed over recent decades in order to reflect classifications comprising only monophyletic groups. In the present study, we provide a generic synopsis of the subfamily Barnadesioideae based on the most recent generic circumscriptions, including a key, expanded morphological descriptions, information on geographical distribution and habitat, photographs and taxonomic notes for all genera.

Rubiacearum Americanarum Magna Hama Pars XLVIII: A New View of Palicourea sect. Axillares and Description of Some New Species (Palicoureeae)

Many of the species classified in Psychotria L. subg. Heteropsychotria Steyerm. (Rubiaceae), including the species of Psychotria ser. Axillares (Hook. f.) Steyerm., have been shown to belong to Palicourea Aubl. based on morphological and molecular characters. This section is now treated as Palicourea sect. Axillares (Hook. f.) Borhidi, and includes 14 species found from southern Central America through the Andes of northwestern and western South America with a center of diversity in eastern Colombia and western Venezuela. This section is characterized by the combination of laminar, well-developed, bilobed stipules and mostly capitate, pseudoaxillary or sometimes terminal, mostly sessile inflorescences with numerous well-developed bracts that enclose the flowers but without enlarged involucral bracts. It is circumscribed differently here than it is by Borhidi. The nomenclatural summary, key, and diagnostic discussions that separate the species included here are based on several new taxonomic circumscriptions. No infraspecific taxa are recognized in Pal. axillaris (Sw.) Borhidi, but one of its varieties from Venezuela is raised to species status as Pal. villipila (Steyerm.) C. M. Taylor. The circumscription of Pal. rosacea (Steyerm.) Borhidi is expanded, and four species are newly described here: Pal. aristata C. M. Taylor from the Andes of southern Ecuador, Pal. quibdoana C. M. Taylor from northwestern Colombia, Pal. santanderiana C. M. Taylor from the Andes of eastern Colombia, and Pal. winfriedii C. M. Taylor from northern Venezuela.

An integrative monograph of Carex section Schoenoxiphium (Cyperaceae)

Carex section Schoenoxiphium (Cariceae, Cyperaceae) is endemic to the Afrotropical biogeographic region and is mainly distributed in southern and eastern Africa, with its center of diversity in eastern South Africa. The taxon was formerly recognized as a distinct genus and has a long history of taxonomic controversy. It has also an important morphological and molecular background in particular dealing with the complexity of its inflorescence and the phylogenetic relationships of its species. We here present a fully updated and integrative monograph of Carex section Schoenoxiphium based on morphological, molecular and cytogenetic data. A total of 1,017 herbarium specimens were examined and the majority of the species were studied in the field. Previous molecular phylogenies based on Sanger-sequencing of four nuclear and plastid DNA regions and RAD-seq were expanded. For the first time, chromosome numbers were obtained, with cytogenetic counts on 44 populations from 15 species and one hybrid. Our taxonomic treatment recognizes 21 species, one of them herein newly described (C. gordon-grayae). Our results agree with previous molecular works that have found five main lineages in Schoenoxiphium. We provide detailed morphological descriptions, distribution maps and analytical drawings of all accepted species in section Schoenoxiphium, an identification key, and a thorough nomenclatural survey including 19 new typifications and one nomen novum.

Rediscovering Rhipsalis hoelleri (Cactaceae), a Critically Endangered species from Brazilian Atlantic Forest

Rhipsalis Gaertner (1788: 138) belongs to Cactaceae Juss., which is among the major taxonomic groups including the highest numbers of threatened species in the world (Goettsch et al. 2015). The center of diversity and endemism of this genus is in the Atlantic Forest in Brazil, a world hotspot of biodiversity (Myers et al. 2000). This forests harbors 5% of all flowering plants species on the planet (Stehmann et al. 2009), including a high diversity of vascular epiphytes. Cactaceae is the sixth most expressive family in terms of number of epiphytes in the Atlantic Forest (2.2% of all vascular epiphyte species at the domain; Freitas et al. 2016) and Rhipsalis is the largest genus of epiphytic cacti (40 species according to Calvente 2012), highlighting the importance of this genus amongst the global epiphytic flora.

Phylogeny and Systematics of Crescentieae (Bignoniaceae), a Neotropical Clade of Cauliflorous and Bat-Pollinated Trees

Abstract—The tribe Crescentieae includes Amphitecna (21 species), Crescentia (six species), and Parmentiera (10 species), three genera of understory trees with a center of diversity in Central America and a small number of species in the Antilles and northern South America. Species in Crescentieae are united by their fleshy, indehiscent fruit and cauliflorous, bat-pollinated flowers. To lay a foundation for examining morphological, ecological, and biogeographic patterns within the tribe, we inferred the phylogeny for Crescentieae using both chloroplast (ndhF, trnL-F) and nuclear markers (PepC, ITS). The most recent circumscription of Crescentieae, containing Amphitecna, Crescentia, and Parmentiera is supported by our phylogenetic results. Likewise, the sister relationship between Crescentieae and the Antillean-endemic Spirotecoma is also corroborated by our findings. This relationship implies the evolution of fleshy and indehiscent fruits from dry and dehiscent ones, as well as the evolution of bat pollination from insect pollination. Fruits and seeds from species in Crescentieae are consumed by humans, ungulates, birds, and fish.

A Taxonomic Treatment of Rogiera (Guettardeae, Rubiaceae)

Abstract—Rogiera (Guettardeae, Rubiaceae) is a Neotropical genus distributed from Mexico to northern South America that includes shrubs, treelets, or trees, which were previously treated in the taxonomically controversial and confused Rondeletia complex. Rogiera can be recognized among other Rubiaceae by the combination of multiflowered inflorescences, heterostylous flowers, quincuncial corolla aestivation, a hairy ring at the corolla mouth, and capsular fruits with loculicidal dehiscence. Despite the recent taxonomic circumscription of Rogiera there is not a comprehensive taxonomic treatment to it. Moreover, regional floristic treatments disagree on the species circumscriptions, with discrepancies in the number of species of Rogiera from 11 to 20. Based on molecular and morphological evidence studied on field and herbarium specimens, we present a taxonomic revision of Rogiera. We recognize ten species; Mexico is the center of diversity with nine species, four of them endemic. An identification key, descriptions, distribution maps, nomenclatural history, phenological data, and illustrations of all the species in the genus are provided for the first time. Several names required lecto- or epitypifications designated here.

Ribosomal DNA revealed an extensive role of allopolyploidy in the radiation of Ulex L

We studied the phylogeny of Ulex L., a genus of spiny legumes, which its center of diversity in the Iberian Peninsula, using ribosomal DNA markers (rDNA), namely ETS, 5.8S and ITS (45S), and 5S intergenic spacer regions. One of the main findings was the presence of very different haplotypes in 5S-IGS genes and, to a less extent, in ETS and ITS, in seven polyploid taxa. We interpreted these results as an indication of hybrid origins and proposed allopolyploidy for U. argenteus ssp. subsericeus, U. australis ssp. australis, U. australis ssp. welwitschianus, U. densus, U. europaeus ssp. europaeus, U. europaeus ssp. latebracteatus, and U. jussiaei. These results reinforce an early hypothesis which stated that the radiation of Ulex occurred mainly by polyplodization.Phylograms showed two main clades, one grouping the hydrophilic U. gallii, U. breoganii and U. minor, and the other grouping the southern, xerophytic, taxa. The putative allopolyploids showed haplotypes, which grouped in both clades, indicating that allopolyploidy, occurred through hybridization from these hydrophilic and xerophytic lineages.The phylogenetic position of U. micranthus is not certain and it is discussed. The 5S-IGS showed to retain more polymorphisms than ETS gene or ITS markers. This result is compatible with the hypothesis that 5S rDNA region is less vulnerable to inter-loci concerted evolution than 45S, providing a more suitable marker for reconstructing histories of allopolyploid species. We discuss the taxonomic consequences of these results.