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Published By American Society Of Plant Taxonomists

1548-2324, 0363-6445

2021 ◽  
Vol 46 (4) ◽  
pp. 951-961
Author(s):  
Jasper John A. Obico ◽  
Hemres Alburo ◽  
Julie F. Barcelona ◽  
Marie Hale ◽  
Lisa Paguntalan ◽  
...  

Abstract— Little is known about the effects of habitat fragmentation on the patterns of genetic diversity and genetic connectivity of species in the remaining tropical forests of Southeast Asia. This is particularly evident in Cebu, a Philippine island that has a long history of deforestation and has lost nearly all of its forest cover. To begin filling this gap, data from 13 microsatellite loci developed for Tetrastigma loheri (Vitaceae), a common vine species in Philippine forests, were used to study patterns of genetic diversity and genetic connectivity for the four largest of the remaining forest areas in Cebu. Evidence of relatively high levels of inbreeding was found in all four areas, despite no evidence of low genetic diversity. The four areas are genetically differentiated, suggesting low genetic connectivity. The presence of inbreeding and low genetic connectivity in a commonly encountered species such as T. loheri in Cebu suggests that the impact of habitat fragmentation is likely greater on rare plant species with more restricted distributions in Cebu. Conservation recommendations for the remaining forest areas in Cebu include the establishment of steppingstone corridors between nearby areas to improve the movement of pollinators and seed dispersers among them.


2021 ◽  
Vol 46 (4) ◽  
pp. 1011-1015
Author(s):  
Priscila Orlandini ◽  
Inês Cordeiro ◽  
Jone Clebson Ribeiro Mendes ◽  
Antônio Campos-Rocha ◽  
Vinicius Castro Souza

Abstract— A new species of Phyllanthus with phylloclades endemic to the State of Bahia is described here. Phyllanthus dracaenoides can be recognized for its peculiar habit that resembles a species of Dracaena, a very unusual height of up to 7 m, the plagiotropic phylloclades spirally arranged, and its vermiform cincinni. Notes on its habitat, taxonomic affinity, conservation status, geographic distribution, illustrations, and photographs are provided.


2021 ◽  
Vol 46 (4) ◽  
pp. 891-915
Author(s):  
Susan Fawcett ◽  
Alan R. Smith ◽  
Michael Sundue ◽  
J. Gordon Burleigh ◽  
Emily B. Sessa ◽  
...  

Abstract— The generic classification of the Thelypteridaceae has been the subject of much controversy. Proposed taxonomic systems have varied from recognizing the approximately 1200 species in the family within the single genus Thelypteris, to systems favoring upwards of 30 genera. Insights on intrafamilial relationships, especially for neotropical taxa, have been gained from recent phylogenetic studies; however, in the most recent classification, 10 of 30 recognized genera are either non-monophyletic or untested. We sequenced 407 nuclear loci for 621 samples, representing all recognized genera and approximately half the known species diversity. These were analyzed using both maximum likelihood analysis of a concatenated matrix and multi-species coalescent methods. Our phylogenomic results, informed by recently published morphological evidence, provide the foundation for a generic classification which recircumscribed 14 genera and recognized seven new genera. The 37 monophyletic genera sampled demonstrate greater geographic coherence than previous taxonomic concepts suggested. Additionally, our results demonstrate that certain morphological characters, such as frond division, are evolutionarily labile and are thus inadequate for defining genera.


2021 ◽  
Vol 46 (4) ◽  
pp. 1080-1085
Author(s):  
Igor H. F. Azevedo ◽  
Pedro L. R. Moraes

Abstract— Sanchezia dubia is described and illustrated as a new species from the department of Madre de Dios in southeastern Peru. Its morphology slightly resembles Sanchezia sprucei, but its most remarkable feature is its close similarity to Suessenguthia, even more so than to those of its own genus. This new species is distinguished from others by its glabrous stem and leaves, its inflorescence containing two to five serial cymose heads, which are sessile to short-pedunculate, with mostly two to four flowers each (occasionally one), its inner bracts ranging in length between 6 and 23 mm, and its androecium composed of two stamens and two mucronate staminodes. We suggest it is an endangered species based on its restricted geographic distribution, its few known populations, and the increasing threats to its habitats. Along with Suessenguthia koessleri, this new species seems to be a key taxon to understanding the phylogenetic relationship between these two genera, which is still uncertain. Additionally, we provide a key to identify the Sanchezia and Suessenguthia species of the Madre de Dios River basin from southern Peru to northern Bolivia.


2021 ◽  
Vol 46 (4) ◽  
pp. 1067-1079
Author(s):  
Ashley R. Keesling ◽  
Michael B. Broe ◽  
John V. Freudenstein

Abstract— Relationships among members of Ericaceae subfamily Monotropoideae have been difficult to resolve due to reduction and convergent evolution in these parasitic plants. All species in this subfamily are fully mycoheterotrophic, meaning they obtain nutrients by parasitizing fungi rather than through photosynthesis. Here, we examine relationships and host specificity in one of the most widespread species in this subfamily, Monotropa uniflora. We use several lines of evidence to investigate whether there is support for recognizing a segregate, M. brittonii, as distinct. Based on molecular and morphological analysis of Monotropa collected throughout its range in the United States, we find two distinct lineages, one of which corresponds morphologically and geographically to Small’s M. brittonii. We identified several morphological characters that differ between the two species. We also observed a high degree of fungal host specificity in M. brittonii, which appears to parasitize almost exclusively Lactifluus subgenus Lactariopsis section Albati. Additionally, M. brittonii was primarily collected from Florida scrub, which are xeric, shrub-dominated habitats that differ substantially from the mesic forests where M. uniflora typically occurs. Based on these molecular, morphological, and ecological differences, we support recognition of M. brittonii as distinct from M. uniflora.


2021 ◽  
Vol 46 (4) ◽  
pp. 916-928
Author(s):  
Amabily Bohn ◽  
Alan R. Smith ◽  
Fernando B. Matos ◽  
Robbin C. Moran ◽  
Paulo H. Labiak

Abstract— Cyclodium is a neotropical fern genus with 13 species, most of them distributed in the Amazonian lowlands, particularly in the Guianan region and along the border with the Andes. It belongs to the polybotryoid clade of Dryopteridaceae, being unique within this clade by a combination of characters related to rhizome growth, leaf dimorphism, anastomosing venation, and peltate indusia. Here we present a molecular phylogenetic hypothesis for Cyclodium resulting from Bayesian and maximum likelihood analyses, using molecular sequences of five plastid markers. We also map 12 morphological characters and habit onto the resulting trees. Our results support Cyclodium as monophyletic and sister to Polybotrya. The presence of peltate indusia is the main character distinguishing Cyclodium. Our results also suggest that plesiomorphic conditions in Cyclodium are free venation (vs. anastomosing), creeping rhizomes (vs. erect or decumbent), highly dissected laminae (vs. 1-pinnate), monomorphic sterile and fertile fronds (vs. dimorphic), and pinnatifid apices (vs. conform).


2021 ◽  
Vol 46 (4) ◽  
pp. 1107-1113
Author(s):  
James B. Beck ◽  
Morgan L. Markley ◽  
Mackenzie G. Zielke ◽  
Justin R. Thomas ◽  
Haley J. Hale ◽  
...  

Abstract— The genus Solidago represents a taxonomically challenging group due to its sheer number of species, putative hybridization, polyploidy, and shallow genetic divergence among species. Here we use a dataset obtained exclusively from herbarium specimens to evaluate the status of Solidago ulmifolia var. palmeri, a morphologically subtle taxon potentially confined to Alabama, Arkansas, Mississippi, and Missouri. A multivariate analysis of both discrete and continuous morphological data revealed no clear distinction between S. ulmifolia var. palmeri and Solidago ulmifolia var. ulmifolia. Solidago ulmifolia var. palmeri’s status was also assessed with a phylogenomic and SNP clustering analysis of data generated with the “Angiosperms353” probe kit. Neither analysis supported Solidago ulmifolia var. palmeri as a distinct taxon, and we suggest that this name should be discarded. The status of Solidago delicatula (formerly known as Solidago ulmifolia var. microphylla) was also assessed. Both morphological and phylogenetic analyses supported the species status of S. delicatula and we suggest maintaining this species at its current rank. These results highlight the utility of the Angiosperms353 probe kit, both with herbarium tissue and at lower taxonomic levels. Indeed, this is the first study to utilize this kit to identify genetic groups within a species.


2021 ◽  
Vol 46 (4) ◽  
pp. 935-950
Author(s):  
Katsuhiro Yashiro ◽  
Yasuhiko Endo

Abstract— The genus Eleocharis (Cyperaceae, monocotyledons) is characterized by bladeless leaves, which are leaves having only leaf-sheaths. To study the evolutionary process through which Eleocharis species lost their leaf blades, we analyzed the outer morphological and anatomical characters of the representative Eleocharis species, plus species from nine phylogenetically related genera. From the analysis, we recognized eight characters and we optimized their character states on a recent molecular phylogenetic tree. As a result, we recognized five characteristics shared by Eleocharis species as follows: (1) the most apical internode is more than seven times longer than the next apical internode; (2) bladeless leaves having only leaf sheaths; (3) transversely septate aerenchyma in culms; (4) densely and peripherally located, slender, and square timber-shaped fiber bundles in culms; and (5) palisade chlorenchyma in culms. In these characteristics, (2) and (4) are synapomorphies of Eleocharis. These two apomorphic characteristics seemed to be adaptations for inhabiting running waters.


2021 ◽  
Vol 46 (4) ◽  
pp. 1131-1140
Author(s):  
Rogério Neves Ribeiro ◽  
Vanessa Lopes Rivera ◽  
João Bernardo de Azevedo Bringel Junior ◽  
Vanina Gabriela Salgado ◽  
Carolyn Elinore Barnes Proença

Abstract— Praxelis scaturicola, a new Cerrado biome species, is described and illustrated. The main morphological features of this new species are: i) capitula usually isolated; ii) vinaceous involucral bracts; iii) reduced glabrous leaves well-spaced on the stem. This study also presents information on aspects of the new species’ habitat, as well as field images and illustrations. Praxelis scaturicola is known only from the Paraúna municipality in Goiás state, Brazil. A key and comments on the Brazilian species of Praxelis are also presented with a special note on the status of P. grandiflora. Additionally, the synonymy of P. macrocarpa under P. capillaris is proposed.


2021 ◽  
Vol 46 (4) ◽  
pp. 962-972
Author(s):  
Matheus Martins Teixeira Cota ◽  
Juliana Gastaldello Rando ◽  
Cristiane Snak ◽  
Luciano Paganucci de Queiroz

Abstract— Plants from Brazilian campos rupestres usually present morphological strategies that allow them to survive in extreme environments. However, in Chamaecrista (Leguminosae, Caesalpinioideae), one of the most diverse genera in the campos rupestres, needle-like leaflets are rare. Reviewing the species that present such leaf morphology, we describe Chamaecrista acicularis, a new species from the Canastra Range, in the southwestern region of the state of Minas Gerais, Brazil. Phylogenetic analyses revealed that C. acicularis is not closely related to other quite similar needle-like leafleted species and that this trait evolved convergently. We also present comments on the phylogenetic relationships of needle-like leafleted species as well as the evolution of the leaflet amplitude, and a detailed description of C. acicularis alongside illustrations, photos, geographical distribution, a key to the needle-like leafleted species and taxonomic notes on similar species. Additionally, we expand the description of Chamaecrista strictifolia and present an informal conservation status for all needle-like leafleted species.


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