A Deep Learning Method for Fully Automatic Stomatal Morphometry and Maximal Conductance Estimation

Stomata are integral to plant performance, enabling the exchange of gases between the atmosphere and the plant. The anatomy of stomata influences conductance properties with the maximal conductance rate, gsmax, calculated from density and size. However, current calculations of stomatal dimensions are performed manually, which are time-consuming and error prone. Here, we show how automated morphometry from leaf impressions can predict a functional property: the anatomical gsmax. A deep learning network was derived to preserve stomatal morphometry via semantic segmentation. This forms part of an automated pipeline to measure stomata traits for the estimation of anatomical gsmax. The proposed pipeline achieves accuracy of 100% for the distinction (wheat vs. poplar) and detection of stomata in both datasets. The automated deep learning-based method gave estimates for gsmax within 3.8 and 1.9% of those values manually calculated from an expert for a wheat and poplar dataset, respectively. Semantic segmentation provides a rapid and repeatable method for the estimation of anatomical gsmax from microscopic images of leaf impressions. This advanced method provides a step toward reducing the bottleneck associated with plant phenotyping approaches and will provide a rapid method to assess gas fluxes in plants based on stomata morphometry.

Pleistocene plants from Zarzal Formation, middle valley of the Cauca River Basin, Colombia

We report macro and meso palaeobotanical records from the Zarzal Formation, in the Cauca River Depression, and the Quindío-Risaralda Basin between the Western and the Central Cordilleras of Colombia. The fossils correspond to leaves and seeds obtained from layers of mudstones, diatomites, and tuffaceous sandstones deposited in the inter-Andean valleys of Cauca and La Vieja rivers, separated by the Serranía Santa Bárbara ridge between the Valle del Cauca and Quindío departments. The sediments of the Pleistocene Zarzal Formation were deposited in a fluvial-lacustrine environment, with volcanic influence originated in the Central Cordillera to the east of the depositional area. The study here presented allowed the identification of thirteen morphotypes of leaf impressions grouped in six Angiosperm families: Poaceae?/Cyperaceae? and Araceae of the Monocots group, Melastomataceae, Fabaceae and Lauraceae belonging to the Eudicots group and one family of Lycopsida: Thelypteridaceae. On the other hand, very well-preserved silicified micro-seeds were grouped in eight morphotypes, belonging to the botanical groups Cyperaceae and Asteraceae. The fossils found allowed us to identify two types of plant associations that exhibit paleofloristic richness. In the Cauca River Basin, an autochthonous to parautocthonous plant association could correspond to a sub-Andean gallery forest, whilst in the La Vieja River Basin a parautocthonous plant association indicates a swamped floodplain. Keywords: paleoflora, leaves, seeds, Cauca River, La Vieja River, lacustrine deposit.

A new Oligocene fern of Dryopteridaceae from the Českéstředohoří Mts (Czech Republic)

A new palaeobotanical site was recovered at artificial excavations within the city district of Ústí nad Labem called Mojžíř in northern Bohemia (Czech Republic) that yielded slabs of Oligocene tephritic pyroclastic rocks with plant impressions. The fossiliferous layer belongs to the Děčín Formation of the České středohoří Mts. dated to the Oligocene (30.8–24.7 Ma). One of the recovered fossils belongs to a new leptosporangiate fern matching modern representatives of Polystichum Roth (Dryopteridaceae Herter). These frond fragments are partly fertile and allow studying the position of sori and details of indusia and spores. This fossil fern is described here as a new species of Polystichum, P. pacltovae Kvaček sp. nov., which matches the modern European species of Polystichum, namely Polystichum braunii (Spenner) Fée . Accompanying plant fossils include another fern frond described as "Aspidium "elongatum Heer (non Swartz) of unknown affinities, fragmentary needles assigned to Pinus cf. hepios (Unger) Unger of the Pinaceae and leaf impressions of Betulaceae comparable to Betula brongniartii Ettingshausen.

Review of The Late Oligocene Flora of Matrý Near Sebuzín (České Středohoří Mts., The Czech Republic)

The Oligocene palaeontological locality on Matrý Hill near Sebuzín in the České středohoří Mts., North Bohemia, belongs to the Děčín Formation and is dated to 30.8-24.7 Ma according to the regional stratigraphy. It has yielded, in addition to insects from the Heteroptera group, a fossil bee Apis petrefacta and palaeobatrachid frogs, also numerous plant remains. Their recovery began in 1996. The plant fossil assemblage consists mostly of leaf impressions, occasionally accompanied by casts or impressions of fruits. Noteworthy are records of a fern Woodwardia muensteriana, conifers Pinus cf. rigios, P. cf. hepios, Calocedrus suleticensis, Tetraclinis salicornioides, Torreya bilinica, cf. Cephalotaxus parvifolia and numerous angiosperms, e.g. Liriodendron haueri, Daphnogene cinnamomifolia, Platanus neptuni, Cercidiphyllum crenatum, Sloanea artocarpites, Ulmus pyramidalis, Celtis pirskenbergensis, Carya fragiliformis, C. quadrangula, Betula brongniartii, B. dryadum, Alnus rhenana, A. cf. kefersteinii, Carpinus grandis, Ostrya atlantidis, Acer crenatifolium, A. cf. palaeosaccharinum, A. integrilobum and Craigia bronnii. Several angiosperm foliage specimens of both monocots and dicots have not yet been identified to a particular genus and species. The fossil plant assemblage at Matrý corresponds to two vegetation types, i.e. a zonal riparian forest and zonal mixed mesophytic forest, as corroborated by the Integrated Plant Record vegetation analysis. The vegetation thrived under a humid climate, characterized by average values of MAT (13.4 °C), WMMT (23.8 °C), CMMT (3.6 °C) and MAP (1,117 mm). The Matry fossil flora is similar in composition to the flora of Žichov from the same Oligocene Děčín Formation in the České středohoří Mts.

Leaf Impressions of Terminalia (Combretaceae) and Daphnogene (Lauraceae) from the Middle Siwalik of the Chatara-Barahakshetra Area, Eastern Nepal

Leaves of Terminalia (Combretaceae) and Daphnogene (Lauraceae) are described from the lower member of Lower Siwalik of Chatara- Barahakshetra area, eastern Nepal. The habit, habitat and present day distribution of the comparable extant taxa indicates the existence of tropical to sub-tropical evergreen to semi evergreen forest with humid climate in the area during the deposition of the Siwalik sediments. Bulletin of Department of Geology, vol. 20-21, 2018, pp: 21-28

Magnolia arroyoana, a new name for Magnolia crassifolia (Magnoliaceae)

Magnolia crassifolia Arroyo & Pérez in Arroyo et al. (2013: 501) is a South American species known only from the type collection, which comes from primary forest found in the Ecuadorian province of Zamora Chinchipe, near the Peruvian-Ecuadorian border. However, it is an illegitimate later homonym of M. crassifolia Göppert (1852: 277), a fossil taxon described on the basis of leaf impressions found in Silesia, Germany. Therefore, the south American species requires a new name (Art 6. 11 of the ICN, McNeill et al. 2012), which is proposed below.

Plio-Pleistocene Plant Megafossils from the Lukundol Formation (Nakkhu Khola, Lalitpur District, Central Nepal)-First Results

The lacustrine sediments of the Kathmandu Basin are rich in plant mega and micro fossils. The Lukundol Formation which is distributed in the southern part of the Kathmandu Basin yielded nicely preserved plant megafossils from different locations. A 5.5 m thick carbonaceous clay bed at the left bank of the Nakkhu Khola, near Chyasikot village, Lalitpur contains abundant plant debris, leaf impressions, seed and fruits, gymnosperm needles and cones. The plant fossils discovered from this location are identified as Berberis asiatica (leaf), Rhododendron arboreum (leaf), Rhododendron barbatum (leaf), Litsea elongata (leaf), Pinus roxburghii (needles and cones) Trapa bispinosa and Trapa quadrispinosa (fruits). Many leaf impressions are also collected from Bungmati and Chovar area. This paper deals with the first reporting of plant fossils from Nakkhu Khola section. The findings from other sections will be reported separately.Journal of Institute of Science and Technology, 2015, 20(1): 141-144

Late Cretaceous flora of James Ross Island (Antarctica) – preliminary report

Fossil plants from Late Cretaceous strata (Hidden Lake Formation and Santa Marta Formation) of James Ross Basin exposed in the northern part of the James Ross Island are preliminary described. Both formations contain plant mega fossils, petrified wood, and charcoalified mesofossils. Fossil plants from the Hidden Lake Formation are represented by leaf impressions of pteridophytes (Microphyllopteris, Delosorus, Lygodium), conifers (Elatocladus, Brachyphyllum, Pagiophyllum, Araucaria, Podozamites vel Lindleycladus), Bennettitales vel Cycadales (Zamites vel Dioonites sp.) and angiosperms (Cinnamomoides, Dicotylophyllum ssp., Proteophyllum, Juglandi-phyllum vel Dicotylophyllum). Fossil wood can be attributed to the very broadly defined morphogenus Antarctoxylon Poole & Cantrill.

Permo-Triassic arthropod trace fossils from the Beardmore Glacier area, central Transantarctic Mountains, Antarctica

Permian and Triassic lacustrine and fluvial-system deposits in the Beardmore Glacier area of the Transantarctic Mountains preserve a superb record of continental environments and evidence of life on extensive bedding plane exposures. They yielded the first invertebrate trackways reported from continental Permo-Triassic deposits of Antarctica, here assigned to the ichnogenera Diplichnites and Diplopodichnus, which were probably produced by myriapodous arthropods. A resting trace is compared to Orbiculichnus and interpreted as generated by a jumping insect. Plant life is represented by leaf impressions, fossil forests and peat, vertebrates by body and trace fossils, and invertebrate shallow infauna by near surface burrows. The small number and diversity of trackways recovered from the large bedding plane exposures suggest that trackway-producing arthropods were rare at these high southern palaeolatitudes.