scholarly journals Cyperaceae in Mexico: Diversity and distribution

2018 ◽  
Vol 96 (2) ◽  
pp. 305 ◽  
Author(s):  
M. Socorro González-Elizondo ◽  
Anton A. Reznicek ◽  
Jorge A. Tena-Flores
Keyword(s):  
Rapid Evolution ◽  
Taxonomic Revision ◽  
Field Work ◽  
The United States ◽  
Herbarium Specimens ◽  
Generic Level ◽  
Holokinetic Chromosomes ◽  
The Family ◽  
Infraspecific Taxa ◽  
High Level

<p><strong>Background</strong>: Cyperaceae, with about 5,500 species and 90 genera worldwide, are the third largest family among Monocots. A unique combination of morphological and karyotypical features, among which stand holokinetic chromosomes, favors a rapid evolution and diversification and a high level of endemism in some groups. Preliminary checklists of Mexican sedges have been published but an updating of the taxonomy and nomenclature of the group for the country is required.</p><p><strong>Questions</strong>: How many and which species and genera of Cyperaceae are in Mexico?, what patterns of geographic distribution display those species?, which are the main gaps in the systematic knowledge in the family?</p><p><strong>Study site and years of study</strong>: Mexico, 1990 to 2016.</p><p><strong>Methods</strong>: A database of Mexican Cyperaceae was generated with basis in literature review, study of herbarium specimens (11 herbaria in Mexico and the United States) and field work, the last mainly focused on <em>Carex</em>. Diversity and endemism level were calculated. Besides, we analyzed in different space scales their distributional range.</p><p><strong>Results</strong>: Our dataset includes 460 species and 20 infraspecific taxa in 21 genera that belong to 10 of the 17 tribes of the family. Subfamily Cyperoideae includes almost 100 % of the Mexican sedges, as only one representative of subfamily Mapanioideae is known for the country. At the generic level, a drastic reduction in number (21) in comparison to previous inventories (27) results of recent phylogenetic and taxonomic rearrangements. The most diverse genera are <em>Carex</em> (138 taxa) and <em>Cyperus</em> (125), followed by <em>Rhynchospora</em> (65) and <em>Eleocharis</em> (57). Sedges in Mexico are found from sea level to above 4,300 m, in all types of vegetation. The highest diversity was found for Chiapas (237 taxa, 52 % of the total) and Veracruz (206 taxa, 45 %), followed by Oaxaca and Jalisco. Two genera (<em>Cypringlea</em> and <em>Karinia</em>) and 111 species or infraspecific taxa are endemic to Mexico (24 %), 43 of them micro-endemic (only known from one state in the country). Endemism increases to 57 % when the biogeographic extension known as Megamexico is included. Forty six names are excluded from the Mexican flora.</p><strong>Conclusions</strong>: Regardless of the addition of taxa and refining of the databases, the checklist presented here is still preliminary. Collection deficiencies and insufficient taxonomic revision for Mexican sedges are reflected in gaps in their knowledge. There are at least 45 undescribed species; including them the richness of Mexican sedges would exceed 500 species. Many complexes of species are in need of taxonomic revision, mainly in <em>Carex</em> but also in<em> Bulbostylis</em>, <em>Cyperus</em>, <em>Eleocharis</em>, <em>Rhynchospora</em> and <em>Scleria</em>. To advance in the inventory and better understanding of the diversity of Mexican Cyperaceae, we propose some research topics to be addressed in the short term.<p> </p>

Taxonomic revision of Sabicea subgenus Anisophyllae (Ixoroideae, Rubiaceae) from Tropical Africa, with four new species

Phytotaxa ◽  
2017 ◽  
Vol 293 (1) ◽  
pp. 1 ◽  
Author(s):  
LISE A. ZEMAGHO ◽  
SIGRID LIEDE-SCHUMANN ◽  
OLIVIER LACHENAUD ◽  
STEVEN DESSEIN ◽  
BONAVENTURE SONKE
Keyword(s):  
New Species ◽  
Conservation Status ◽  
Taxonomic Revision ◽  
Herbarium Specimens ◽  
Field Observations ◽  
Tropical Africa ◽  
Center Of Diversity ◽  
Infraspecific Taxa ◽  
Group A ◽  
Species Descriptions

A taxonomic revision of Sabicea subgenus Anisophyllae (Rubiaceae), a group restricted to Central and East Africa, is presented here. This work, based on a study of herbarium specimens and field observations in Cameroon and Gabon, includes a survey of the morphological features of the group, a key to the species, descriptions of all the taxa, and IUCN conservation status assessments. Fifteen species are recognised, four of which are described as new (Sabicea mapiana, S. ndjoleensis, S. parmentierae, S. sciaphilantha), three former varieties are raised to species rank (S. crystallina, S. jacfelicis, S. tersifolia), and one species previously sunk into synonymy is restored (S. bequaertii). Two new infraspecific taxa are also described, Sabicea crystallina subsp. engongensis and S. sciaphilantha subsp. hirsuta. The group has its center of diversity in Gabon, where 10 of the 15 species occur, three of them being endemic to the country.

scholarly journals A taxonomic evaluation of the Thesium confine species complex (Santalaceae)

Bothalia ◽  
2018 ◽  
Vol 48 (1) ◽  
Author(s):  
Kagiso S. Mashego ◽  
M. Marianne Le Roux
Keyword(s):  
Species Complex ◽  
Growth Form ◽  
Taxonomic Revision ◽  
Morphological Characters ◽  
Research Strategy ◽  
Herbarium Specimens ◽  
African Species ◽  
Separate Species ◽  
Distribution Ranges ◽  
The Family

Background: Thesium L. is the largest genus in the family Santalaceae (sandalwood family). The last taxonomic revision of the southern African species dates back to 1925. An urgent revision of the genus is required as indicated in a recent national biosystematics research strategy for South Africa.Objectives: To revise the Thesium confine species complex (Thesium durum, T. confine and Thesium spartioides) and to update the typification, nomenclature, descriptions and distribution ranges.Method: Morphological characters were studied using own field collections as well as herbarium specimens from K, NU, PRE and PRU and images on Global Plants (JSTOR). Distribution ranges of the studied species were updated.Results: An examination of morphological characters revealed great similarity between T. spartioides and T. confine. Both species have an herbaceous habit, decumbent growth form, terminal (or less frequently axillary) inflorescences and a sympatric northern distribution in South Africa. Thesium durum differs from T. spartioides and T. confine in having a shrubby habit, erect growth form and axillary inflorescences and occurs in the southern part of South Africa.Conclusion: Thesium spartioides is synonymised under T. confine, and T. durum is retained as a separate species.

scholarly journals Distribution and diversity of Fagaceae in Hidalgo, Mexico

2017 ◽  
Vol 95 (4) ◽  
pp. 660
Author(s):  
Susana Valencia-A. ◽  
Gabriel Flores-Franco ◽  
Jaime Jiménez-Ramírez ◽  
Mauricio Mora-Jarvio
Keyword(s):  
Taxonomic Revision ◽  
Morphological Description ◽  
Herbarium Specimens ◽  
Sierra Madre Oriental ◽  
Red Oaks ◽  
Dichotomous Key ◽  
Sierra Madre ◽  
The Family ◽  
Herbarium Data ◽  
High Diversity

<p><strong>Background:</strong> The family Fagaceae is one of the most important in temperate regions of the Northern hemisphere. <em>Fagus</em> and <em>Quercus</em> are distributed in Mexico, the former in Northeastern Mexico, while the latter reaches a high diversity in the Sierra Madre Oriental, Mexico. In Hidalgo state, located mainly in the Sierra Madre Oriental, knowledge of the Fagaceae diversity is still uncertain.<em></em></p><p><strong>Questions and/or hypothesis:</strong> We carried out a taxonomic revision of the genus and species of Fagaceae in Hidalgo state. We determined how many and which species are distributed in Hidalgo. We also present a morphological description and ecological characters of each one.</p><p><strong>Studied species:</strong> The species of the family Fagaceae</p><p><strong>Study site:</strong> Hidalgo state, Mexico.</p><p><strong>Method:</strong> We collected herbarium specimens, made field observations and reviewed herbarium data of Fagaceae specimens at FCME, INEGI, MEXU, ENCB, SLPM, HUMO, XAL and partly BH herbaria. In addition, we checked taxonomic literature and protologues of each species.</p><p><strong>Results: </strong>We found one species of <em>Fagus</em> and 43 of <em>Quercus</em>, 22 of which belong to the section <em>Quercus</em> (white oaks) and 21 to section <em>Lobatae</em> (red oaks). Morphological descriptions, altitudinal and geographical distribution, vegetation types of each species and a dichotomous key for species identification are presented. Illustrations and photographs of the species are also included.</p><p><strong>Conclusions:</strong> A high diversity of Fagaceae species is present in Hidalgo state. In Mexico, Hidalgo ranks in fifth place for oak species diversity, just behind Oaxaca (50 species), Puebla (50), San Luis Potosí (45), and Jalisco (45).<strong></strong></p>

Updated checklist and conservation status of Cactaceae in the state of Durango, Mexico

Phytotaxa ◽  
2017 ◽  
Vol 327 (2) ◽  
pp. 103 ◽  
Author(s):  
MARTHA GONZÁLEZ-ELIZONDO ◽  
M. SOCORRO GONZÁLEZ-ELIZONDO ◽  
JESÚS GUADALUPE GONZÁLEZ-GALLEGOS ◽  
JORGE A. TENA-FLORES ◽  
I. LORENA LÓPEZ ENRIQUEZ ◽  
...  
Keyword(s):  
Conservation Status ◽  
Field Work ◽  
Data Matrix ◽  
Tropical Region ◽  
Herbarium Specimens ◽  
Generic Level ◽  
Specific Level ◽  
New Information ◽  
Mexican State ◽  
Annotated Checklist

An updated and annotated checklist of Cactaceae in the Mexican state of Durango is provided, supported by a thorough examination of specialized literature and herbarium specimens, as well as field work. Additionally, geographical distribution, endemism and conservation status of the species were analyzed based on a compiled data matrix with 2326 georeferenced records. Cactaceae comprises 137 species and 29 genera in Durango, which represent a high proportion of the Mexican cactus flora: 46−58% at the generic level and 20−23% at the specific level. The estimated richness according to Chao-2 and Jackknife-1 is 143 and 151 species respectively, which means that the inventory we present here for the Cactaceae of Durango is complete in 91 to 96%.  Since no herbarium specimens nor registers in reliable data bases were found to support their presence in the area, 46 taxa were excluded; even so, this inventory increases by 30% the cacti richness previously reported for Durango and provides new information on the distribution range of many species. The richest genera are Mammillaria, Opuntia, Coryphantha and Echinocereus. The highest concentration of species occurs in the arid and semiarid zone of eastern Durango, although there are also some spots with significant richness in the tropical region on the western slopes of the Sierra Madre Occidental. 75% of the species are endemic to Mexico, 41% are regional endemics and 5% are restricted to Durango. New records and relevant novelties are also discussed.

scholarly journals La familia Convolvulaceae en el municipio de Victoria, Tamaulipas, México

2019 ◽  
Vol 97 (3) ◽  
pp. 539
Author(s):  
Estefanía Guadalupe Fernández-Puga ◽  
Arturo Mora-Olivo ◽  
Andrew McDonald ◽  
Edilia De la Rosa-Manzano
Keyword(s):  
Morphological Diversity ◽  
Point Of View ◽  
Herbarium Specimens ◽  
Plant Family ◽  
Online Databases ◽  
Disturbed Areas ◽  
The Family ◽  
Infraspecific Taxa ◽  
Local Levels ◽  
Species Study

<p><strong>Background:</strong> The Convolvulaceae a plant family of near-cosmopolitan distribution includes 58 genera and 1,880 species. This family presents a remarkable amount of morphological diversity and even includes parasitic species. Knowledge of Convolvulaceae in Mexico is still scanty, since few geographical areas of Mexico have been investigated with respect to this family or any of its genera.</p><p><strong>Questions:</strong> How many and which species of Convolvulaceae are found in the municipality of Victoria? How are they distributed within the study area and worldwide?</p><p><strong>Species study:</strong> Species of the family Convolvulaceae.</p><p><strong>Site and years of study:</strong> Victoria, Tamaulipas, Mexico, 2017-2018.</p><p><strong>Methods:</strong> Botanical material was collected and identified using standard botanical bibliographies. Herbarium specimens and online databases were reviewed. The distribution of the species in the study area was examined by a cluster analysis.</p><p><strong>Results:</strong> Nine genera were registered, 31 species with two infraspecific taxa. The richest genus is <em>Ipomoea</em> (13 spp.), followed by <em>Cuscuta</em> (4) and <em>Evolvulus</em> (4). Most of the species occur below 500 m a.s.l., and mostly in scrubs and disturbed areas. A high percentage (77.3 %) of native Convolvulaceae species has wide geographical distributions and only two species are endemic to Mexico, one of which is endemic to Tamaulipas. Taxonomic keys of genera and species are included.</p><strong>Conclusions:</strong> Although the Convolvulaceae in Victoria, Tamaulipas, do not present exceedingly high rates of species richness, it is still necessary to continue with explorations at national and local levels to fully elucidate the biological importance of the region from a biogeographical point of view.

CYTOTAXONOMIC STUDIES ON RUMEX SECTION AXILLARES

1958 ◽  
Vol 36 (6) ◽  
pp. 947-996 ◽  
Author(s):  
Nina Marie Sarkar
Keyword(s):  
Pollen Fertility ◽  
Diploid Species ◽  
Taxonomic Revision ◽  
The United States ◽  
Herbarium Specimens ◽  
Tetraploid Species ◽  
Structural Hybridity ◽  
The North ◽  
Essentially Normal ◽  
Very High

The present investigation covers only the North American species of Rumex subgenus Rumex (Lapathum) section Axillares. A review was made of all the previous taxonomical and cytological work done in this group. All the species of the section Axillares were morphologically studied and their natural distribution plotted on maps. The distributional data were derived from about 3000 herbarium specimens gathered from various herbaria in the United States and Canada. Chromosome numbers of 17 taxa of the section Axillares were determined. The three subsections were found to comprise a polyploid series, the monotypic subsection Venosi with 2n = 40, R. verticillatus of the subsection Verticillati with 2n = 60, and all but two of the species studied in the subsection Salicifolii with 2n = 20; the two exceptions were R. mexicanus and R. utahensis, both with 2n = 40. Meiosis was studied in the species of the subsection Salicifolii only. Both the diploid and the tetraploid species showed essentially normal meiotic behavior. Pollen fertility was also very high in all the species. A number of intra- and inter-specific hybridizations were made between the taxa in the subsection Salicifolii, involving both the diploid and the tetraploid species. The resulting diploid (diploid × diploid), triploid (diploid × tetraploid), and tetraploid (tetraploid × tetraploid) F1 hybrids were both morphologically and cytologically studied. Morphologically almost all the diploid and tetraploid hybrids were intermediate between the two parents. The triploid hybrids showed more similarity to the tetraploid species involved in the cross, Meiosis in all the diploid hybrids was essentially normal with 10 bivalents. However, there was a significant decrease in chiasma frequency as compared with the parent species. This was postulated to be due to cryptic structural hybridity. There were three different categories of pollen fertility, ranging from low to very high, which were not correlated with any meiotic irregularities. All the diploid hybrids were fertile and set abundant seeds. Meiosis in the triploid hybrids was very irregular with mostly 10 bivalents and 10 univalents at metaphase I. Anaphases were also irregular, resulting in numerous micronuclei. All the triploid hybrids were sterile and set only a few undeveloped seeds. Meiosis in the tetraploid hybrid studied was also irregular with mostly 9 bivalents and 22 univalents. It was thus postulated that both the tetraploid species are allotetraploids with one genome in common between them and that this genome is essentially the same one shared by the diploid species so far cytologically studied. The tetraploid hybrids were completely sterile and did not set any seed. From the cytogenetic data, the diploid species studied were shown to be very closely interrelated. However, no taxonomic revision was undertaken owing to lack of more complete data involving all the species comprising the group.

Breaking Free

2017 ◽  
Author(s):  
Deirdre David
Keyword(s):  
United States ◽  
The United States ◽  
The Novel ◽  
Male Homosexuality ◽  
Domestic Life ◽  
The Family

In the mid- to late 1950s, Pamela emerged as a critically acclaimed novelist, particularly after the family returned to London. In perhaps her best-known novel, The Unspeakable Skipton, she explores the life of a paranoid writer who sponges on English visitors to Bruges. The novel was hailed for its wit and sensitive depiction of the life of a writer. She also published a fine study of a London vicar martyred in marriage to a vain and selfish wife: The Humbler Creation is remarkable for its incisive and empathetic depiction of male despair. The Last Resort sealed her distinction as a brilliant novelist of domestic life in its frank depiction of male homosexuality. While continuing to publish fiction, Pamela maintained her reputation as a deft reviewer. In 1954, she and Charles travelled to the United States—the first of many trips that were to follow.

Student Privacy and the Law in the Internet Age

2019 ◽  
Author(s):  
Leah Plunkett ◽  
Urs Gasser ◽  
Sandra Cortesi
Keyword(s):  
Learning Environments ◽  
School Environment ◽  
Privacy Protection ◽  
Data Privacy ◽  
Digital Technologies ◽  
The United States ◽  
Legal Framework ◽  
Privacy Law ◽  
Student Privacy ◽  
High Level

New types of digital technologies and new ways of using them are heavily impacting young people’s learning environments and creating intense pressure points on the “pre-digital” framework of student privacy. This chapter offers a high-level mapping of the federal legal landscape in the United States created by the “big three” federal privacy statutes—the Family Educational Rights and Privacy Act (FERPA), the Children’s Online Privacy Protection Act (COPPA), and the Protection of Pupil Rights Amendment (PPRA)—in the context of student privacy and the ongoing digital transformation of formal learning environments (“schools”). Fissures are emerging around key student privacy issues such as: what are the key data privacy risk factors as digital technologies are adopted in learning environments; which decision makers are best positioned to determine whether, when, why, and with whom students’ data should be shared outside the school environment; what types of data may be unregulated by privacy law and what additional safeguards might be required; and what role privacy law and ethics serve as we seek to bolster related values, such as equity, agency, and autonomy, to support youth and their pathways. These and similar intersections at which the current federal legal framework is ambiguous or inadequate pose challenges for key stakeholders. This chapter proposes that a “blended” governance approach, which draws from technology-based, market-based, and human-centered privacy protection and empowerment mechanisms and seeks to bolster legal safeguards that need to be strengthen in parallel, offers an essential toolkit to find creative, nimble, and effective multistakeholder solutions.

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