Tocoyena longilobata, a replacement name for Posoqueria speciosa (Gardenieae, Rubiaceae)

Phytotaxa ◽  
2020 ◽  
Vol 477 (2) ◽  
pp. 297-300
Author(s):  
RODRIGO L. BORGES ◽  
MARIA ALVES ◽  
NÁDIA ROQUE
Keyword(s):  
Seed Shape ◽  
Generic Concept ◽  
Generic Delimitation

Aublet (1775) described Posoqueria Aublet (1775: 133, tab. 51) and differentiated it from Tocoyena Aublet (1775: 131, tab. 50) by the number of locules of the ovary (unilocular vs. bilocular, respectively) and seed shape (angulate vs. subspherical, respectively). However, in subsequent studies, L.C.M.Richard (1792) and Lamarck (1793) published under Tocoyena certain species that morphologically matched the generic concept of Posoqueria, causing an historical confusion concerning their generic delimitation. Achille Richard (1830), in his Mémoire sur la famille des Rubiacées, synonymized Posoqueria under Tocoyena, a generic delimitation not widely adopted by subsequent authors. For example, Schumann (1889) in Flora Brasiliensis treated Posoqueria and Tocoyena as distinct genera.

Wood Structure and Generic Status of Some Southern African Cassinoideae (Celastraceae)

IAWA Journal ◽  
1993 ◽  
Vol 14 (4) ◽  
pp. 373-389 ◽  
Author(s):  
Robert H. Archer ◽  
Abraham E. van Wyk
Keyword(s):  
Anatomical Study ◽  
Wide Sense ◽  
Wood Structure ◽  
African Species ◽  
Generic Concept ◽  
Generic Delimitation ◽  
Quantitative Characters ◽  
Qualitative Characters ◽  
Perforation Plates ◽  
Anatomical Evidence

Opinions differ on whether to treat Cassine in southern Africa in a wide sense, or to recognise several segregate genera, such as Elaeodendron, Crocoxylon, Lauridia, Mystroxylon and Cassine s. str. A comparative anatomical study was made of mature wood representing 17 southern African species of Cassine s.l., Pleurostylia and the three monotypic genera, Allocassine, Hartogiella and Maurocenia (all members of the subfamily Cassinoideae). The wood structure is described with emphasis on the taxonomic value of quantitative and qualitative characters. Various features were found to be diagnostic at supraspecific level. The presence or absence of scalariform perforation plates, septate fibres, various ray types, and additional quantitative characters could be useful for taxonomic application, especially for generic delimitation. Three principal wood types, of which one encompasses three subtypes, are recognised among the species examined. Wood anatomical evidence tells against a wide generic concept for Cassine, and favours the recognition of segregate genera.

A Politics of Intensity: Some Aspects of Acceleration in Simondon and Deleuze

2017 ◽  
Vol 11 (4) ◽  
pp. 498-517
Author(s):  
Yuk Hui ◽  
Louis Morelle
Keyword(s):  
Conceptual Framework ◽  
The Other ◽  
Generic Concept ◽  
Philosophical Thought ◽  
Ontological Ground ◽  
Shed Light

This article aims to clarify the question of speed and intensity in the thoughts of Simondon and Deleuze, in order to shed light on the recent debates regarding accelerationism and its politics. Instead of starting with speed, we propose to look into the notion of intensity and how it serves as a new ontological ground in Simondon's and Deleuze's philosophy and politics. Simondon mobilises the concept of intensity to criticise hylomorphism and substantialism; Deleuze, taking up Simondon's conceptual framework, repurposes it for his ontology of difference, elevating intensity to the rank of generic concept of being, thus bypassing notions of negativity and individuals as base, in favour of the productive and universal character of difference. In Deleuze, the correlation between intensity and speed is fraught with ambiguities, with each term threatening to subsume the other; this rampant tension becomes explicitly antagonistic when taken up by the diverse strands of contemporary accelerationism, resulting in two extreme cases in the posthuman discourse: either a pure becoming, achieved through destruction, or through abstraction that does away with intensity altogether; or an intensity without movement or speed, that remains a pure jouissance. Both cases appear to stumble over the problem of individuation, if not disindividuation. Hence, we wish to raise the following question: in what way can one think of an accelerationist politics with intensity, or an intensive politics without the fetishisation of speed? We consider this question central to the interrogation of the limits of acceleration and posthuman discourse, thus requiring a new philosophical thought on intensity and speed.

Systematics, Biogeography, and Morphological Character Evolution of the Hemiepiphytic Subfamily Monsteroideae (Araceae)

2019 ◽  
Vol 104 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Alejandro Zuluaga ◽  
Martin Llano ◽  
Ken Cameron
Keyword(s):  
Dna Sequences ◽  
Pacific Islands ◽  
R Package ◽  
Morphological Characters ◽  
Ancestral State ◽  
Seed Shape ◽  
Long Distance ◽  
The Pacific ◽  
And Migration ◽  
The Tropics

The subfamily Monsteroideae (Araceae) is the third richest clade in the family, with ca. 369 described species and ca. 700 estimated. It comprises mostly hemiepiphytic or epiphytic plants restricted to the tropics, with three intercontinental disjunctions. Using a dataset representing all 12 genera in Monsteroideae (126 taxa), and five plastid and two nuclear markers, we studied the systematics and historical biogeography of the group. We found high support for the monophyly of the three major clades (Spathiphylleae sister to Heteropsis Kunth and Rhaphidophora Hassk. clades), and for six of the genera within Monsteroideae. However, we found low rates of variation in the DNA sequences used and a lack of molecular markers suitable for species-level phylogenies in the group. We also performed ancestral state reconstruction of some morphological characters traditionally used for genera delimitation. Only seed shape and size, number of seeds, number of locules, and presence of endosperm showed utility in the classification of genera in Monsteroideae. We estimated ancestral ranges using a dispersal-extinction-cladogenesis model as implemented in the R package BioGeoBEARS and found evidence for a Gondwanan origin of the clade. One tropical disjunction (Monstera Adans. sister to Amydrium Schott–Epipremnum Schott) was found to be the product of a previous Boreotropical distribution. Two other disjunctions are more recent and likely due to long-distance dispersal: Spathiphyllum Schott (with Holochlamys Engl. nested within) represents a dispersal from South America to the Pacific Islands in Southeast Asia, and Rhaphidophora represents a dispersal from Asia to Africa. Future studies based on stronger phylogenetic reconstructions and complete morphological datasets are needed to explore the details of speciation and migration within and among areas in Asia.

Detection and Mapping of RAPD Markers Associated with QTL Affecting Seed Size and Shape in Common Bean

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 547b-547
Author(s):  
Soon O. Park ◽  
Dermot P. Coyne ◽  
Geunhwa Jung ◽  
E. Arnaud-Santana ◽  
H. Ariyarathne
Keyword(s):  
Linkage Group ◽  
Common Bean ◽  
Seed Size ◽  
Phenotypic Variation ◽  
Seed Weight ◽  
Rapd Markers ◽  
Rapd Marker ◽  
Seed Shape ◽  
Seed Length ◽  
Ri Lines

Seed size is an important trait in common bean. The objective was to identify RAPD markers associated with QTL for seed weight, seed length, and seed height in a molecular marker-based linkage map in a recombinant inbred (RI) population from the common bean cross of the larger seeded (100 seed/39 to 47 g) PC-50 (ovate seed shape) × smaller seeded (100 seed/26 to 35 g) XAN-159 (flat rhomboidal seed shape). The parents and RI lines were grown in two separate greenhouse and two field (Wisconsin, Dominican Republic) experiments using a RCBD. Continuous distributions for seed weight, seed length, and seed height were observed for RI lines indicating quantitative inheritance. One to three QTLs affecting seed weight explained 17% to 41% of the phenotypic variation. Two to three QTLs for seed length explained 23% to 45% of the phenotypic variation. One to four QTL associated with seed height explained 17% to 39% of the phenotypic variation. A RAPD marker M5.850 in linkage group 3 was consistently associated with seed weight, seed length, and seed height in all experiments and explained 7% to 13% of the phenotypic variation for these traits. A seedcoat pattern morphological marker (C) in linkage group 1 was associated with seed weight and seed height in two greenhouse experiments.

scholarly journals 4-CPA (4-Chlorophenoxyacetic Acid) Induces the Formation and Development of Defective “Fenghou” (Vitis vinifera × V. labrusca) Grape Seeds

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 515
Author(s):  
Zhenhua Liu ◽  
Yan Wang ◽  
Wenjiang Pu ◽  
Haifeng Zhu ◽  
Jinjun Liang ◽  
...  
Keyword(s):  
Vitis Vinifera ◽  
Outer Integument ◽  
Underlying Mechanism ◽  
Grape Seeds ◽  
Endosperm Tissue ◽  
Seed Shape ◽  
Seed Formation ◽  
Significant Difference ◽  
Fruit Setting ◽  
Chlorophenoxyacetic Acid

For some horticultural plants, auxins can not only induce normal fruit setting but also form fake seeds in the induced fruits. This phenomenon is relatively rare, and, so far, the underlying mechanism remains unclear. In this study, “Fenghou” (Vitis vinifera × V. labrusca) grapes were artificially emasculated before flowering and then sprayed with 4-CPA (4-chlorophenoxyacetic acid) to analyze its effect on seed formation. The results show that 4-CPA can induce normal fruit setting in “Fenghou” grapes. Although more seeds were detected in the fruits of the 4-CPA-treated grapevine, most seeds were immature. There was no significant difference in the seed shape; namely, both fruit seeds of the grapevines with and without 4-CPA treatment contained a hard seed coat. However, the immature seeds lacked embryo and endosperm tissue and could not germinate successfully; these were considered defective seeds. Tissue structure observation of defective seeds revealed that a lot of tissue redifferentiation occurred at the top of the ovule, which increased the number of cell layers of the outer integument; some even differentiated into new ovule primordia. The qRT-PCR results demonstrated that 4-CPA application regulated the expression of the genes VvARF2 and VvAP2, which are associated with integument development in “Fenghou” grape ovules. Together, this study evokes the regulatory role of 4-CPA in the division and continuous redifferentiation of integument cells, which eventually develop into defective seeds with thick seed coats in grapes.

A Seed Shape Mutant of Arabidopsis That Is Affected in Integument Development

1994 ◽  
Vol 6 (3) ◽  
pp. 385 ◽  
Author(s):  
Karen M. Leon-Kloosterziel ◽  
Christian J. Keijzer ◽  
Maarten Koornneef
Keyword(s):  
Seed Shape

scholarly journals Short-term study on the yak dung seed bank on the Qinghai-Tibetan Plateau: effects of grazing season, seed characteristics and forage preferences

2021 ◽  
Author(s):  
Shulin Wang ◽  
Fujiang Hou
Keyword(s):  
Tibetan Plateau ◽  
Plant Species ◽  
Seed Bank ◽  
Seedling Density ◽  
Seed Shape ◽  
Grazing Season ◽  
Size And Shape ◽  
Foraging Preferences ◽  
Seed Characteristics ◽  
Yak Dung

Abstract Aims Viable seeds in herbivore dung constitute the dung seed bank, and the contribution of livestock dung to this seed bank in grazing pastures is often overlooked. Grazing season (warm and cold), seed characteristics (size and shape), and forage preference are the main factors that affect the size and composition of the dung seed bank and ultimately affect grassland ecology. However, how these three factors interact is unclear. Methods We collected yak dung as well as seeds of the common plant species from warm- and cold-season alpine meadows in northeastern Qinghai-Tibetan Plateau, and explored how grazing season (warm and cold), seed characteristics (size and shape) and foraging preferences (temporary cages method) affects yak dung seedling density, richness and diversity in an alpine pasture. Results Forty-three plant species (mainly perennials) germinated from yak dung. Dung seedling density, richness, and diversity did not differ significantly between the two grazing seasons. Small to medium-sized spherical seeds (seed size < 10 mg, shape index < 0.5) had the greatest germination potential. Conclusions Yaks vary their forage preference depending on the season (phenological period), and endozoochory occurs throughout both grazing seasons. Seed shape and size directly regulate the dung seedling density, richness, and diversity. Dung seedlings increase the heterogeneity of the aboveground vegetation near the microsites of the dung pieces and therefore promote grassland patching. Our study demonstrates that grazing season, seed characteristics, and yak forage preferences affect the dung seed bank in grazing ecosystems.

Taxonomic notes on the genus Hedyotis sensu lato (Rubiaceae) in China

Phytotaxa ◽  
2019 ◽  
Vol 414 (3) ◽  
pp. 121-128
Author(s):  
RUI-JIANG WANG
Keyword(s):  
New Combination ◽  
Morphological Comparison ◽  
Generic Delimitation ◽  
New Synonyms ◽  
Flora Of China

The genus Hedyotis sensu lato was splitted into several genera on basis of morphological and molecular evidences. Under this generic delimitation, seven new taxonomic treatments, including six new synonyms and one new combination, are proposed for the Flora of China. The name Hedyotis tenelliflora that misapplied to Scleromitrion angustifolium is also corrected with morphological comparison.

scholarly journals THE GENERIC CONCEPT IN THE CLASSIFICATION OF THE FLOWERING PLANTS

Science ◽  
1906 ◽  
Vol 23 (577) ◽  
pp. 81-92 ◽  
Author(s):  
B. L. ROBINSON
Keyword(s):  
Flowering Plants ◽  
Generic Concept

Review of Insulestremia Jaschhof, 2004 (Diptera; Cecidomyiidae; Lestremiinae) with description of two new species from Brazil

Zootaxa ◽  
2021 ◽  
Vol 4966 (3) ◽  
pp. 367-375
Author(s):  
ANTONIO MARCELINO DO CARMO-NETO ◽  
CARLOS JOSÉ EINICKER LAMAS ◽  
MARIA VIRGINIA URSO-GUIMARÃES
Keyword(s):  
New Species ◽  
Galapagos Islands ◽  
Monotypic Genus ◽  
Galápagos Islands ◽  
Generic Concept ◽  
Two New Species

This study presents the first records of the subfamily Lestremiinae and the genus Insulestremia Jaschhof in Brazil. Insulestremia, a previously monotypic genus described from the Galapagos Islands, has three species in Brazil: I. sinclairi Jaschhof, I. amorimi sp. nov. and I. amenti sp. nov. The new species are described, the generic concept is reviewed, and a key to the species of Insulestremia is provided. 

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