Search results for "Micromorphology"
showing 9 items of 19 documents
Flower and fruit structure of the endangered species Petagnaea gussonei (Sprengel) Rauschert (Saniculoideae, Apiaceae) and implications for its repro…
2015
Petagnaea gussonei (Apiaceae) is an endangered species endemic to the Nebrodi mountains (north-eastern Sicily). Although an increasing number of studies have been performed on this species, its reproductive biology remains poorly understood. The aim of this study was to investigate in detail the structure of the flower and the fruit of Petagnaea, and the possible implications for its breeding system and seed dispersal mechanism. Results from fieldwork, light microscopy and scanning electron microscopy suggest (1) the presence of protandrous hermaphrodite flowers; (2) geitonogamy, autogamy, and allogamy as breeding system mechanisms of P. gussonei, even if asexual reproduction is preferred b…
Plant morphology: outdated or advanced discipline in modern plant sciences?
2019
In the last decades, with the increase of molecular studies, the study of plant forms has gone through a steady decline in interest, and researches on this topic are often neglected and underestimated. Notwithstanding, comparative morphology as integrative discipline still assumes a pivotal role in modern sciences, remaining fundamentally relevant to nearly all fields of plant biology, such as systematics, evolutionary biology, ecology, physiology, genetics, molecular biology, not to mention also agriculture, bioengineering, and forensic botany. Contrary to common belief, plant morphology is not a conservative finished science, but, like other sciences, it is open to constant innovations in…
First data on the taxonomic diversity of the Portulaca oleracea aggregate (Portulacaceae) in Iran
2017
The review of specimens from Iran belonging to the Portulaca oleracea L. aggregate resulted in the recognition of six microspecies: P. cypria Danin, P. granulatostellulata (Poelln.) Ricceri & Arrigoni, P. nitida (Danin & H.G.Baker) Ricceri & Arrigoni, P. rausii Danin, P. socotrana Domina & Raimondo, and P. trituberculata Danin, Domina & Raimondo, all reported for the first time for the flora of Iran. The identification was based on the microscopic study of seeds. It is noted that P. oleracea is not confirmed for Iran. Distribution data and an identification key for Portulaca microspecies in Iran are presented.
The role of pedogenic overprinting in the obliteration of parent material in some polygenetic landscapes of Sicily (Italy)
2016
Abstract Many soils older than the Holocene have experienced several changes, and possess properties that may be due to the complex effect of several stages of soil development; these soils are called polygenetic. It is still rather unclear, however, if, as time elapses, pedogenic processes tend to diverge generating different soils, or converge towards increasingly similar soils. We studied five pedons (37°60′N, 13°90′E) exposed to present weathering simultaneously since the Holocene but located on Upper Miocene or Holocene parent material. Their XRD and FTIR clay mineralogy reveal an overall homogeneity; smectites, calcite and gypsum reach the thermodynamic equilibrium, a slight undersatu…
A new synonym and a new combination in Stipa aliena Keng (Poaceae: Stipa sect. Regelia)
2015
Stipa section Regelia comprises three species occurring in mountainous areas of Central Asia. One of them, S. smithii , was described by Martinovský in 1970, but the taxon has been overlooked in later taxonomical studies. The species was described with two varieties, var. smithii and var. macrocarpa . As a result of our taxonomical studies, we find the typical variety of the taxon to be conspecific with Stipa aliena , and propose that the second one be recognized as Stipa aliena var. macrocarpa comb. nov. Remarks on species belonging to section Regelia and micromorphological patterns of their lemma morphologies are discussed. A key to species close to S. aliena is provided.
Stipa klimesii (Poaceae), a new species from Western Himalayas (India)
2014
Stipa klimesii sp. nov. from the Western Himalayas (India: Ladakh) and its variety S. klimesii var. pubescens var. nov. are described. The new species is similar to S. roborowskyi but differs by its longer anthecium, longer ligules of vegetative shoots, longer hairs on seta and shorter awns. Stipa klimesii is also similar to S. purpurea, but differs by longer ligules of vegetative shoots, shorter awns, slightly shorter hairs on seta and by the character of the panicle, which is compressed and with straight branches in S. klimesii vs. lax and with flexuous branches in S. purpurea. Epidermal patterns of the lemma in S. klimesii and both above-mentioned species, were examined by scanning elect…
Clastic injection dynamics during ice front oscillations: A case example from Sólheimajökull (Iceland).
2015
18 pages; International audience; Soft-sediment deformation structures are being increasingly used as a tool for reconstructing palaeoenvironments and porewater pressure conditions in glacial settings. However, the potential of hydrofractures and clastic injections in the reconstruction of ice dynamics remains poorly constrained. This paper presents the results of a detailed study of a clastic injection network outcropping in the Sólheimajökull forefield (South Iceland). Sedimentological descriptions are combined with microscopic to macroscopic analyses of clastic injection geometries, sediment-fills, and cross-cutting relationships. The 250 m long and 20 m high exposure observed along the …
Allium sphaeronixum (Amaryllidaceae), A New Species from Turkey
2023
In this paper, Allium sphaeronixum, a new species of the sect. Codonoprasum from Turkey, is described and illustrated. The new species is endemic to Central Anatolia, limited to the area of Nevşehir, where it grows on sandy or rocky soil at an elevation of 1000–1300 m a.s.l. Its morphology, phenology, karyology, leaf anatomy, seed testa micromorphology, chorology, and conservation status are examined in detail. The taxonomic relationships with the closest allied species, A. staticiforme and A. myrianthum, are also highlighted and discussed.