Thomas F. Daniel

Phylogenetic Relationships among Acantheae (Acanthaceae): Major Lineages Present Contrasting Patterns of Molecular Evolution and Morphological Differentiation

Abstract We used DNA sequence data from four regions ([1] nrITS; the chloroplast [2] rps16 intron, [3] trnG-S spacer, and [4] trnL-F intron and spacer) to study phylogenetic relationships within tribe Acantheae (Acanthaceae). Our sample includes 18 of 20 recognized genera and 82 of ca. 500 species (plus two Justicieae as out-groups). Results of parsimony and Bayesian analyses were entirely congruent and provided strong support for monophyly of two sub-lineages of Acantheae, referred to here as the ‘one-lipped corolla’ and ‘two-lipped corolla’ lineages, reflecting notable differences in corolla morphology. Subsequent analyses were of the two sublineages separately in order to include all characters (a hypervariable region of trnG-S could not be aligned across the full range of taxa but could be aligned within sublineages). The ‘one-lipped corolla lineage’ comprises six clades of Old World taxa related as follows: [Crossandra (Sclerochiton clade {Cynarospermum [Blepharis (Acanthus clade + Acanthopsis)]})]. All presently recognized genera are strongly supported as monophyletic, except that Blepharis dhofarensis is placed with species of Acanthus, with strong support from both parsimony and Bayesian inference (monophyly of Blepharis was rejected by both parsimony and likelihood). Alternate hypotheses based on calyx and androecial morphology regarding Crossandrella and Streptosiphon could not be rejected, but placement of these genera with some species of Crossandra based on pollen was rejected. The ‘two-lipped corolla lineage’ is strongly supported and includes one clade of Old World plants (the Stenandriopsis clade) that is sister to a strongly supported clade that includes all New World Acantheae as follows: [Stenandrium clade (Neriacanthus {Aphelandra lineage})]. The Aphelandra lineage includes the ‘armed’ Aphelandra clade and a polytomy of six unresolved clades: (1) A. squarrosa, (2) Encephalosphaera clade, (3) Geissomeria clade, (4) A. aurantiaca clade, (5) A. pulcherrima clade, (6) Rhombochlamys. In contrast to patterns in the one-lipped lineage, genera in the two-lipped lineage are mostly not monophyletic nor are relationships among them strongly supported by our molecular data or by morphological synapomorphies. We discuss these results in the context of evidence from other sources including macromorphology, palynology, chromosome numbers, and geographic distribution.

Toward a comprehensive understanding of phylogenetic relationships among lineages of Acanthaceae s.l. (Lamiales)

Acanthaceae (Asteridae; Lamiales) include ∼4000 species and encompass a range of morphological diversity, habitats, and biogeographic patterns. Although they are important components of tropical and subtropical habitats worldwide, inadequate knowledge of the familys phylogenetic framework has impeded comparative research. In this study, we sampled all known lineages of Acanthaceae including Andrographideae. Also included were eight of 13 genera whose relationships remain enigmatic. We used sequence data from nrITS and four chloroplast noncoding regions, and parsimony and Bayesian methods of analysis. Results strongly support most aspects of relationships including inclusion of Avicennia in Acanthaceae. Excepting Neuracanthus, newly sampled taxa are placed with strong support; Kudoacanthus is in Justicieae, Tetramerium lineage, and the remaining enigmatic genera are in Whitfieldieae or Barlerieae, and Andrographideae are sister to Barlerieae. This last result is unanticipated, but placement of Andrographideae based on structural characters has been elusive. Neuracanthus is monophyletic but placement relative to (Whitfieldieae (Andrographideae + Barlerieae)) is weakly supported. Many clades have clear morphological synapomorphies, but nonmolecular evidence for some remains elusive. Results suggest an Old World origin with multiple dispersal events to the New World. This study informs future work by clarifying sampling strategy and identifying aspects of relationships that require further study.

Phylogenetic relationships within Ruellieae (Acanthaceae) and a revised classification.

Phylogenetic knowledge of the large plant family Acanthaceae has been greatly advanced over the last 2 decades. Studies have demonstrated the existence of several major lineages, most of which have been the focus of subsequent investigation. Missing among these is comprehensive study of the 48 genera currently classified in tribe Ruellieae, a pantropical lineage that includes several species-rich genera. We compared the number of validly published names to current estimates of species richness per genus in Ruellieae and found more than 2600 names available for ∼1200 species. Using molecular data from two nuclear (ITS+5.8S, Eif3E) and three chloroplast (trnG-trnR, trnG-trnS, psbA-trnH) markers, we test the placement of these 48 genera in Ruellieae, explore the monophyly of currently recognized taxa, and propose morphological features to diagnose major clades within the tribe. We were able to sample all but four of 48 genera, and all were resolved in Ruellieae except Zygoruellia. Many monospecific or oligospecific genera are nested within clades of more species-rich genera. We propose several new generic synonymies to reflect these results and insights from morphology. Finally, we present a revised classification of Ruellieae that contains seven subtribes. A solid phylogenetic hypothesis of relationships within Ruellieae contributes to progress in biology in three important ways: (1) it enables better assessment of trait homologies and thus characters upon which genera are delimited, (2) it contributes to the Global Strategy for Plant Conservation’s initiative to document plant biodiversity, and (3) it facilitates cross-family comparative evolutionary analyses, including large-scale hypothesis testing of biogeographic patterns, clade size asymmetries, and differential diversification within Acanthaceae.

The Tetramerium Lineage (Acanthaceae: Acanthoideae: Justicieae) : Delimitation and Intra-lineage Relationships Based on cp and nrITS Sequence Data

Abstract We used DNA sequence data from five genic regions (nrlTS; chloroplast trnL-F, trnT–L, rps16, trnS–G) to study phylogenetic relationships of the Tetramerium lineage (Acanthaceae: Justicieae). From a sample of 70 species (representing 25 genera) previously affiliated with the Tetramerium lineage, 68 are included therein. Our analyses excluded Papuasian Calycacanthus and Neotropical Streblacanthus monospermus from the Tetramerium lineage; however, two species described in Justicia (J. gonzalezii and J. medranoi) and a Malagasy species of uncertain generic affinities are nested within the lineage. A monophyletic Tetramerium lineage consists of 23 currently recognized genera with at least 168 species, more than 70% of which occur in the New World. Old World Chlamydocardia and Clinacanthus are serially sister to all other members of the lineage. Other Old World taxa consist of: Ecbolium clade (all sampled species of Ecbolium plus Malagasy Papulina richardii), Megalochlamys clade (Megalochlamys, Trichaulax and the unidentified Malagasy species), and two isolated taxa (Angkalanthus and Chorisochora). All analyses strongly support monophyly of the New World Tetramerium lineage. The basal dades of New World plants, all with nototribic flowers, are: 1) the taxonomically heterogeneous but palynologically consistent Mirandea clade, and 2) the Pachystachys clade + the South American Anisacanthus clade. The second is sister to all other NW plants, referred to here as the core Tetramerium lineage. We recognize five clades within the core Tetramerium lineage related as follows: (Henrya clade (Carlowrightia parviflora clade (North American Anisacanthus clade (core Carlowrightia clade + Tetramerium)))). Macromorphological synapomorphies are unknown for the Tetramerium lineage and for many of its constituent clades. However, we propose sternotribic flowers as synapomorphic for the core Tetramerium lineage, and flowers with the lower-central lobe of the corolla modified into a keel as a synapomorphy for a lineage consisting of Tetramerium and the core Carlowrightia clade. Palynological characters provide putative synapomorphies for some clades (e.g. Ecbolium clade, Mirandea clade) and autapomorphies for several species (e.g. Mexacanthus mcvaughii, Trichaulax mwasumbii). An Old World origin is postulated for the Tetramerium lineage, and we posit a single dispersal event to America and subsequent extensive radiation there, especially in arid zones of Mexico and adjacent regions. Taxonomic implications of our results are extensive. Notably, many traditionally recognized genera (e.g. Anisacanthus, Carlowrightia, Mirandea) are not monophyletic and emphasis on floral form often has been phylogenetically misleading; for example, floral adaptations to pollination by hummingbirds have evolved at least eight times in the New World Tetramerium lineage.

The Tetramerium lineage (Acanthaceae: Justicieae) does not support the Pleistocene Arc hypothesis for South American seasonally dry forests

PREMISE OF THE STUDY The Tetramerium lineage (Acanthaceae) presents a striking ecological structuring in South America, with groups concentrated in moist forests or in seasonally dry forests. In this study, we investigate the circumscription and relationships of the South American genera as a basis for better understanding historic interactions between dry and moist biomes in the Neotropics. METHODS We dated the ancestral distribution of the Tetramerium lineage based on one nuclear and four plastid DNA regions. Maximum parsimony, maximum likelihood, and Bayesian inference analyses were performed for this study using 104 terminals. Phylogenetic divergences were dated using a relaxed molecular clock approach and ancestral distributions obtained from dispersal-vicariance analyses. KEY RESULTS The genera Pachystachys, Schaueria, and Thyrsacanthus are nonmonophyletic. A dry forest lineage dispersed from North America to South America and reached the southwestern part of the continent between the end of the Miocene and beginning of the Pleistocene. This period coincides with the segregation between Amazonian and Atlantic moist forests that established the geographic structure currently found in the group. CONCLUSIONS The South American genera Pachystachys, Schaueria, and Thyrsacanthus need to be recircumscribed. The congruence among biogeographical events found for the Tetramerium lineage suggests that the dry forest centers currently dispersed throughout South America are relatively old remnants, probably isolated since the Neogene, much earlier than the Last Glacial Maximum postulated by the Pleistocene Arc hypothesis. In addition to exploring the Pleistocene Arc hypothesis, this research also informs evolution in a lineage with numerous geographically restricted and threatened species.

Three New Species of Mendoncia (Acanthaceae) from Madagascar

Abstract. Three species of Mendoncia Vell. ex Vand. (Acanthaceae) are newly recognized from Madagascar: M. decaryi (Benoist) E. Magnaghi, M. delphina E. Magnaghi, and M. kely E. Magnaghi. Each is based on a unique suite of morphological characters, and all are endemic to Madagascar. A key to the six species of the genus known from Madagascar is provided. A lectotype is designated for M. cowanii (S. Moore) Benoist var. decaryi Benoist.

Chorological and taxonomic notes on African plants

Abstract The taxonomy of complicated native African taxa, Biscutella maritima (Brassicaceae) and annual species of Sesuvium (Aizoaceae) is discussed. The distribution of B. maritima is widened to the most of the coastal areas of NE Algeria and N Tunisia. Morphological differences with regard to other North African members of Biscutella ser. Biscutella are reported to facilitate the identification of B. maritima. We propose to accept four annual Sesuvium species (instead of the one previously accepted species, S. sesuvioides sensu amplissimo) with different distributions in Africa: S. digynum, S. hydaspicum, S. sesuvioides s.str. and S. nyasicum. A delimitation key based on morphological and carpological characters is provided. Lectotypes of S. digynum, S. digynum var. angustifolium, S. hydaspicum, S. nyasicum, Diplochonium sesuvioides (Sesuvium sesuvioides) and Trianthema polysperma (synonym of Sesuvium hydaspicum) are selected. Other discussed taxa belong to the alien elements of the flora. Atriplex semibaccata (Amaranthaceae-Chenopodiaceae) is reported as a new species for Cape Verde. Gaillardia × grandiflora (Asteraceae) is discovered as a new species for Africa found in Morocco. Prosopis velutina (Fabaceae) is collected for the first time in Northern Africa (Morocco). Mollugo verticillata (Molluginaceae) is recorded as a new species for DR Congo. Its morphology, including seed ornamentation, is discussed in reference to other similar-looking Molluginaceae. Incidence of American species Heterotheca subaxillaris (Asteraceae) in North Africa is discussed. Vernonanthura polyanthes (Asteraceae) is recorded as a naturalized invasive species in eastern Zimbabwe. It seems to be the first documented discovery of this ergasiophyte in Africa.

Four New Species of Anisotes (Acanthaceae) from Madagascar

Abstract.  Four species of Anisotes Nees (Acanthaceae) are described from northern and west-central Madagascar: A. hygroscopicus T. F. Daniel, Letsara & Martín-Bravo, A. perplexus T. F. Daniel, Letsara & Martín-Bravo, A. subcoriaceus T. F. Daniel, Letsara & Martín-Bravo, and A. venosus T. F. Daniel, Letsara & Martín-Bravo. A key to the six species of the genus known from Madagascar, all of them endemic to the island, is provided. Morphological features previously unknown in the genus are noted for A. hygroscopicus and A. venosus (hygroscopic trichomes on seeds), A. subcoriaceus (2-colporate, pseudocolpate pollen lacking insulae), and A. perplexus (2-pororate pollen). None of these species can be treated with certainty in any of the currently recognized sections of Anisotes. Data pertinent to the conservation status of each species are provided.

William R. Anderson—Recipient of the 2008 Asa Gray Award

1 William R. Anderson was awarded the 2008 Asa Gray Award at the annual meeting of the American Society of Plant Taxonomists (ASPT) in Vancouver, British Columbia. Even a cursory glance at Bill’s accomplishments reveals a remarkable career spanning five decades. Bill’s contributions to our understanding of the Malpighiaceae, his mentoring of a large and outstanding group of graduate students, his many years as director of the University of Michigan Herbarium, his contributions as editor of a major flora of western Mexico, his cogent arguments for rational interpretation of the International Code of Botanical Nomenclature, and his work on behalf of the ASPT and other professional organizations exemplify the accomplishments of an individual of uncommon intellect and extraordinary generosity. Bill was born in 1942 in Tucson, Arizona, where he lived for nine years. During those early formative years, Bill developed a love for arid lands and the western United States, and probably encountered his first Malpighiaceae in Sabino Canyon. He was raised in Huntington, West Virginia, and formally began his career in systematics as an undergraduate at Duke University, where he was encouraged by Robert L. Wilbur. While at Duke he and fellow student Marshall Crosby spent two summers in the field, first in Jamaica (1963) collecting for the Duke Herbarium, and subsequently in Hawaii (1964) working on the fern genus Elaphoglossum —research that resulted in his first two publications on higher plants. As a graduate student at the University of Michigan Bill developed interests that have guided his entire career: research on the Malpighiaceae, and a focus on the flora of western Mexico. At Michigan Bill worked under the guidance of Rogers McVaugh, who had been immersed for many years in a study of the flora of western Mexico. Bill began his dissertation work studying Gaudichaudia , a large and complex genus of Malpighiaceae. It soon became apparent that the breeding system, possible hybridization, and high levels of polyploidy in that genus had produced an unusually problematic taxonomic situation that was better suited to postgraduate work. This encounter with malpighs piqued Bill’s interest in resolving some of their taxonomic and reproductive complexities. Although his eventual dissertation research on Crusea did not result in a lifelong dedication to the Rubiaceae, his publication of the resultant comprehensive monograph ( Anderson 1972 ) was awarded the Jesse R. Greenman Award for the best paper originating from a dissertation in plants systematics. That study included one of the early phylogenies based on explicit methodologies for a genus of plants. Some years later Bill revisited phylogeny of Crusea using a different set of cladistic methodologies ( Estabrook and Anderson 1979 ) and obtained a nearly identical result. While a graduate student, Bill met Christiane Seidenschnur, a fellow graduate student also working under the supervision of Rogers McVaugh. Bill and Chris were married in 1967. Numerous fun-filled evenings playing “Mensch ärgere dich nicht” ensued, along with several trips to Mexico to collect material of Trixis (Asteraceae) for Chris’s dissertation, and Oxalis for their friend and fellow student Melinda Denton. William R. Anderson—Recipient of the 2008 Asa Gray Award

Sciaphyllum amoenum (Acanthaceae) is a Peruvian Streblacanthus

Sciaphyllum amoenum has been known solely from cultivated plants of unknown or- igin. This species exhibits all of the diagnostic characteristics of Streblacanthus but is not conspe- cific with any previously described species of that genus. The cultivated specimens, including the type, of S. amoenum correspond to an undescribed series of collections from Peru. Thus the species is transferred to Streblacanthus, and its place of origin can be established. Streblacanthus amoenus is com- pared with the other species of this genus of Amer- ican plants. Streblacanthus boliviensis is considered to be a synonym of S. dubiosus.