Mac H. Alford

Enhancing PCR Amplification of DNA from Recalcitrant Plant Specimens Using a Trehalose-Based Additive

Premise of the study: PCR amplification of DNA extracted from plants is sometimes difficult due to the presence of inhibitory compounds. An effective method to overcome the inhibitory effect of compounds that contaminate DNA from difficult plant specimens is needed. Methods and Results: The effectiveness of a PCR additive reagent containing trehalose, bovine serum albumin (BSA), and polysorbate-20 (Tween-20) (TBT-PAR) was tested. PCR of DNA extracted from fresh, silica-dried, and herbarium leaf material of species of Achariaceae, Asteraceae, Lacistemataceae, and Samydaceae that failed using standard techniques were successful with the addition of TBT-PAR. Conclusions: The addition of TBT-PAR during routine PCR is an effective method to improve amplification of DNA extracted from herbarium specimens or plants that are known to contain PCR inhibitors.

The Future of Botanical Monography: Report from an international workshop, 12-16 March 2012, Smolenice, Slovak Republic

Monographs are fundamental for progress in systematic botany. They are the vehicles for circumscribing and naming taxa, determining distributions and ecology, assessing relationships for formal classification, and interpreting long-term and short-term dimensions of the evolutionary process. Despite their importance, fewer monographs are now being prepared by the newer generation of systematic botanists, who are understandably involved principally with DNA data and analysis, especially for answering phylogenetic, biogeographic, and population genetic questions. As monographs provide hypotheses regarding species boundaries and plant relationships, new insights in many plant groups are urgently needed. Increasing pressures on biodiversity, especially in tropical and developing regions of the world, emphasize this point. The results from a workshop (with 21 participants) reaffirm the central role that monographs play in systematic botany. But, rather than advocating abbreviated models for monographic products, we recommend a full presentation of relevant information. Electronic publication offers numerous means of illustration of taxa, habitats, characters, and statistical and phylogenetic analyses, which previously would have been prohibitively costly. Open Access and semantically enhanced linked electronic publications provide instant access to content from anywhere in the world, and at the same time link this content to all underlying data and digital resources used in the work. Resources in support of monography, especially databases and widely and easily accessible digital literature and specimens, are now more powerful than ever before, but interfacing and interoperability of databases are much needed. Priorities for new resources to be developed include an index of type collections and an online global chromosome database. Funding for sabbaticals for monographers to work uninterrupted on major projects is strongly encouraged. We recommend that doctoral students be assigned smaller genera, or natural portions of larger ones (subgenera, sections, etc.), to gain the wo r k sh o p r epo r t

Nomenclatural Innovations in Neotropical Salicaceae

ABSTRACT Macrothumia M. H. Alford is described as a new genus of Salicaceae based on Neosprucea kuhlmannii Sleumer from Brazil. The deciduous perianth, papillate leaf teeth, presence of receptacular disk glands, and analyses of plastid DNA data suggest that the new genus is more closely related to Ahernia Merrill and Pleuranthodendron L. O. Williams than to Banara Aublet or Neosprucea Sleumer. The monotypic genus Aphaerema Miers of Brazil and Argentina is transferred to Abatia Ruiz & Pavón, based on analyses of plastid DNA sequences and on the lack of morphological discontinuities between the genera. Because the name Abatia spicata (Turczaninow) Sleumer already exists, Abatia angeliana M. H. Alford is published as a replacement name for Aphaerema spicata Miers. A lectotype for Aphaerema spicata is also designated. The monotypic Hispaniolan genus Priamosia Urban, originally described as separate from Xylosma G. Forster based on its few stamens (four, instead of eight to numerous), is transferred to Xylosma, and a neotype is designated for Xylosma domingensis (Urban) M. H. Alford.

A New Species of Commelina (Commelinaceae) from Tanzania

Commelina polhillii Faden & Alford, a new annual species of Commelina with buff-orange flowers, is described from Tanzania. It differs from the similar C. subulata primarily in seed morphology. However, staminode shape, the presence of basal lobes on the medial anther connective, and differences in spathe pubescence also serve to varying extent to distinguish the two taxa. Leaf anatomy reveals one major difference but primarily helps to unite the two species with a group of approximately seven other species. A preliminary chromosome count, 2n = ca. 30, is recorded.

New circumscription of the genus Gamochaeta (Asteraceae, Gnaphalieae) inferred from nuclear and plastid DNA sequences

Gamochaeta (tribe Gnaphalieae, Asteraceae) is composed of ca. 60 species primarily distributed in tropical and subtropical America. Within the tribe Gnaphalieae, the genus is characterized by capitula arranged in spikes or head-like clusters, few hermaphroditic central florets, truncate style branches with apical sweeping trichomes, pappus bristles connate at the base into a ring falling as a unit, and achenes with globose twin trichomes. Previous molecular phylogenetic studies have suggested the paraphyly of the genus, but have not provided a basis for redefining generic limits due to incomplete taxon sampling. To address this problem, DNA sequences from the plastid (trnL-F) and nuclear (ETS and ITS) genomes were analyzed from a broad taxon sample representing the full range of morphological variation known in the genus. Our results affirm that Gamochaeta is paraphyletic as presently circumscribed. Two clades can be recognized: one clade that includes the majority of the species currently assigned to Gamochaeta and a second clade that includes Gamochaetopsis, Stuckertiella and seven species of Gamochaeta. We present here a new circumscription of Gamochaeta, including two new combinations, Gamochaeta alpina and Gamochaeta peregrina, and the resurrection of Gamochaeta capitata. Our results also show Omalotheca supina, O. norvegica and O. sylvatica, which were placed by some authors in Gamochaeta or in Gnaphalium, form a monophyletic group distantly related to both genera.

Checklist of the Vascular Flora of the Gopher Farm Sandhill, Wayne County, Mississippi

ABSTRACT  A survey to document the vascular flora of the Gopher Farm sandhill, Wayne County, Mississippi, was conducted from 2011 to 2015. As a part of the Chickasawhay Ranger District of the DeSoto National Forest, the Gopher Farm represents one of the most northerly sandhills in the Coastal Plain of Mississippi and one the largest publicly owned sandhills in the state. The survey resulted in 194 species, including 2 ferns, 3 gymnosperms, and 189 flowering plants. Of these, 45 are endemic to the Atlantic and Gulf Coastal Plain of the United States, and 6 are listed as rare species by the Mississippi Natural Heritage Program. The collection of Morella inodora represents the most northerly collection of that species in Mississippi.

Louisiana: Bryophyllum daigremontianum and Bryophyllum delagoense (Crassulaceae) New to Louisiana

Bryophyllum daigremontianum (Raym.-Hamet & H. Perrier) A. Berger (CRASSULACEAE)—Orleans Parish: New Orleans, 6009 Magazine Street, 2985520.10 N, 9080718.45 W, 30 Dec 2013, McNair 1729 (USMS). Significance. A small population of Bryophyllum daigremontianum (Kalanchoe daigremontiana), a native of the Indian Ocean islands, was observed growing from concrete cracks in the city of New Orleans. The plants have been become serious weeds in some parts of Florida and Texas, as well as Australia (Moran 2009). Recently, a population was documented in Alabama (Barger et al. 2012). We did not find any sexually reproducing plants, but Herrera et al. (2012) have suggested that the invasive success of B. daigremontianum ‘‘depends exclusively on plantlet recruitment.’’ These plantlets, forming from the leaf margins, are a conspicuous feature of the genus and were present in the population we observed. Bryophyllum delagoense (Ecklon & Zeyher) Schinz (CRASSULACEAE)—Jefferson Parish: Gretna, 187 Willow Dr., 29854 20.96 N, 90802 46.91 W, 8 May 2013, Turnbull s.n. (USMS). Significance. A population of Bryophyllum delagoense (Kalanchoe delagoensis), also native to the Indian Ocean islands and invasive in parts of Florida, Texas, and Australia (Moran 2009), was observed growing around the base of live oak trees (Quercus virginiana Mill.) a residential area in Jefferson Parish. Plantlet formation was also observed in this population. Since neither of these species has been reported for Louisiana in major databases or treatments (Moran 2009; Allen 2010; Kartesz 2013; USDA, NRCS 2013), our collections apparently represent new records for the state. Both plants are cultivated as ornamentals and may have escaped from nearby plantings. Finally, it should also be noted that a hybrid of these two species, referred to as Bryophyllum 3 houghtonii (D.B. Ward) P.I. Forst., also commonly occurs in the same range as its parents, and much of the B. daigremontianum material in the USA, including ours, may represent some hybridization with B. delagoense (Moran 2009).