Stomata in Senftenbergia plumosa (Artis)

Fig. 5. Drawing of the stomata that appear on epidermis of Senftenbergia plumosa; A: actinocytic type (based on photograph Plate IV, 2); B: cyclocytic type (based on photograph Plate IV, 3); S, subsidiary cells; G, guard cells; P, papillae.  

Cuticles and spores of Senftenbergia plumosa (Artis) Bek and Pšenička from the Carboniferous of Pilsen Basin, Bohemian Massif

by Pšenička J., Bek J. (2003)

===

In Review of Palaeobotany and Palynology 125(125):299-312 – DOI: 10.1016/S0034-6667(03)00006-X –

https://www.researchgate.net/publication/230561120_Cuticles_and_spores_of_Senftenbergia_plumosa_Artis_Bek_and_Psenicka_from_the_Carboniferous_of_Pilsen_Basin_Bohemian_Massif

Fig. 6. Types of the stomata used throughout the text. (A) polocytic, (B) copolocytic, (C) seppolocytic, (D) desmocytic, (E) codesmocytic, (F) pericytic, (G) copericytic, (H) cyclocytic , (I) actinocytic (according to Sen and De (1992) and Van Cotthem (1970); supplemented by the authors). 

Abstract

Senftenbergia plumosa (Artis) is an abundant Carboniferous fern occurring in the Central and Western Bohemian Carboniferous basins of the Czech Republic.

Its epidermal structures are described in detail for the first time. The abaxial cuticles are very thin. The cells are isodiametric, random, pentagonal or hexagonal in shape.

Fig. 4. Reconstruction of an abaxial cuticle based on photographs ¢gured on Plate IV; O, ordinary cells; P, papillae; G, guard cells; S, subsidiary cells; T, trichome basis.  

Stomata occur only on the abaxial side of the pinnules. They are irregularly scattered and more or less oriented in one direction; ca. 200 per mm 2 , of the actinocytic or cyclocytic, flush with the epidermal cells.

The abaxial and adaxial surfaces contain small trichome bases. Sporangia are of the Senftenbergia type with Raistrickia type spores. These are different from those of the previously described fertile specimens of S. plumosa from Bohemia, suggesting a large morphological variability of spores in this species.

The epidermal structures of S. plumosa are important for understanding the systematic position of this Carboniferous fern. Generally, the cuticle of S. plumosa is more similar (especially its irregularly, polygonal cells with straight anticlinal wall and cyclocytic stomata) to that of living species of Marattiaceae than of Schizaeaceae.

The epidermal cells of S. plumosa are very similar to those of the Tedelea glabra. It appears to confirm that S. plumosa is a member of the primitive Carboniferous fern family Tedeleaceae (Jennings and Eggert, 1977; Taylor and Taylor, 1993; Bek and Psenicka, 2001).

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Estimating paleo-atmospheric pCO2 from stomatal frequency

Estimating paleo-atmospheric pCO2 during the Early Eocene Climatic Optimum from stomatal frequency of Ginkgo, Okanagan Highlands, British Columbia, Canada

by Smith R. Y., Greenwood D. R., Basinger J. F. (2010)

Robin Y. Smith, a, David R. Greenwood, b, James F. Basinger, a

Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK, Canada S7N 5E2

bDepartment of Biology, Brandon University, 270 18th Street, Brandon, MB, Canada R7A 6A9

===

In Palaeogeography, Palaeoclimatology, Palaeoecology 293: 120-131 – https://doi.org/10.1016/j.palaeo.2010.05.006 – 

https://www.sciencedirect.com/science/article/pii/S003101821000283X

Abstract

Estimates of pCO2 for the early Paleogene vary widely, from near modern-day levels to an order of magnitude greater, based on various proxy measures.

Resolving the relationship between climate and pCO2 during this globally warm period is a key task in understanding climate dynamics in a warmer world.

Here, we use the stomatal frequency of fossil Ginkgo adiantoides from the Okanagan Highlands of British Columbia, Canada to estimate pCOduring the Early Eocene Climatic Optimum (EECO), the interval of peak warmth in the Cenozoic.

We also examine a dataset of modern Ginkgo biloba leaves to critically assess the accuracy and precision of stomatal frequency as a proxy indicator of pCO2. Early Eocene fossil G. adiantoides has significantly lower stomatal frequency than modern G. biloba, suggesting pCO2 levels > 2× modern pre-industrial values.

This result is in contrast to earlier studies using stomatal frequency of Ginkgo that indicated near modern-day levels of pCO2 in the early Paleogene, though not including samples from the EECO. We also find that levels of pCO2 as indicated by stomatal frequency are correlated with trends in climate (mean annual temperature) over time at the Falkland fossil locality, suggesting that climate and pCO2 were coupled during the EECO hyperthermal.

The ecological significance of leaf and cuticular micromorphology, e.g. stomata

Fig. 2. a) Transmitted light image of Tetraclinis articulata cuticle displaying stomata arranged in papillate sunken furrow (scale = 100 μ m); b) fl uorescence image of abaxial surface of Taxus baccata displaying epidermal and stomatal papillae (scale = 20 μ m); c) fl uorescence image of the cross-section of stomata of Sciadopitys verticillata displaying overarching papillae (scale = 50 μ m); d) fl uorescence image of abaxial surface of Wollemia nobilis displaying stomatal wax plugs (scale = 50 μ m); transmitted light images of papillate (e) and non- papillate (f) stomatal complexes of Pseudofrenelopsis parceramosa (scale = 50 μ m); SEM images of sun (g) and shade (h) leaves of Ginkgo biloba (scale = 100 μ m).

Hot, dry, wet, cold or toxic? Revisiting the ecological significance of leaf and cuticular micromorphology

by Haworth M., McElwain J. C. (2008)

Matthew Haworth, Italian National Research Council, Rome, Italy

Jennifer C. McElwain, Trinity College Dublin, Ireland

===

In Palaeogeography Palaeoclimatology Palaeoecology 262(1):79-90 – DOI: 10.1016/j.palaeo.2008.02.009 – –

https://www.researchgate.net/publication/223286688_Hot_dry_wet_cold_or_toxic_Revisiting_the_ecological_significance_of_leaf_and_cuticular_micromorphology

Abstract

Fossil plant morphological traits have been used extensively as palaeoenvironment and palaeoclimate indicators. Xeromorphic features are considered to be structural adaptations that reduce water loss (e.g. thick cuticle, sunken stomata, epidermal papillae and trichomes, stomatal papillae and stomata arranged in sunken grooves), and their presence in fossil plants is often used to indicate palaeo-environmental aridity.

However, in living plants, xeromorphic traits are not restricted to plants subjected to water stress and are commonly observed in plants growing in environments with high precipitation, humidity and water availability. These “xeromorphic” features often serve multiple functions such as water-repellence, defence and protection from excess light. The use of “xeromorphic” features as indicators of palaeo-environmental aridity therefore requires reinterpretation.

Here we review the ecological functions of “xeromorphic” adaptations in extant plants and analyse the equivocal nature of these morphological features using the extinct Cretaceous conifer Pseudofrenelopsis parceramosa (Fontaine) Watson.

We track the occurrence of stomatal papillae (waxy lobes over-hanging the stomatal pit) that are commonly considered to have an anti-transpirant function, in P. parceramosa through Valanginian–Barremian sediments deposited in a fresh water lowland environment at Worbarrow Bay, Dorset, southern England.

The presence/absence of stomatal papillae in P. parceramosa does not display a pattern consistent with an anti-transpirant function. In the context of supporting sedimentological, geochemical and climate modelling evidence we hypothesise that the primary function of stomatal papillae may be to repel liquid water, in addition to other functions such as providing structural support, pathogen-defence and as a response to high atmospheric particulate content caused by localised volcanism.

Our review presents a new palaeo-environmental interpretation of a widespread and important mid-Cretaceous conifer but also provides an updated synthesis of palaeo-environmental data that can be interpreted from “xeromorphic” features in fossil plants.

Stomata in fossil Winteraceae

Figure 4. 1-4. Extant Winteraceae. Note the highly granular texture in each example. 1. Belliolum haplopus, TLM detail of single stomatal complex (AQ117672, scale-bar = 20 µm); 2. B. burttianum, TLM detail of single stomatal complex (AQ463392, scale-bar = 20 µm); 3. Exospermum stipitatum, TLM detail of single stomatal complex (AQ391245, scale-bar = 20 µm); 4. Zygogynum balansae, TLM detail of single stomatal complex (AQ391241, scalebar = 20 µm).

Dispersed leaf cuticle from the Early Miocene of southern New Zealand

by Pole M. (2008)

Mike Pole

Nanging Institute of Geology and paleontology, CAS, China

===Stoma t

In Palaeontologia Electronica 11(15) –

https://www.researchgate.net/publication/266797560_Dispersed_leaf_cuticle_from_the_Early_Miocene_of_southern_New_Zealand

Abstract

This paper describes 115 parataxa of dispersed leaf fossil cuticle from 120 samples from the Early Miocene of Central Otago (the fluvial-lacustrine Manuherikia Group) and Southland (the coastal deltaic East Southland Group), New Zealand.

Figure 5. 1-6. Extant Atherospermataceae. 1. Doryphora sassafras, TLM view showing stomatal complexes and a massively-thickened trichome attachment scar (AQ217598, scale-bar = 50 µm); 2. D. sassafras, TLM view showing two stomatal complexes (AQ217598, scale-bar = 20 µm). Note the distinctive outer stomatal rim; 3. Laurelia novaezealandiae, TLM view showing stomatal complexes and a massively-thickened trichome attachment scar (OPH7027, scale-bar = 50 µm); 4. L. novae-zealandiae, TLM detail of single stomatal complex (OPH7027, scale-bar = 20 µm). Note the distinctive outer stomatal rim; 5. D. aromatica, TLM view showing stomatal complexes (AQ607275, scale-bar = 50 µm); 6. D. aromatica, TLM detail of single stomatal complex (AQ607275, scale-bar = 20 µm). Note the distinctive outer stomatal rim.

The modern affinities include Argophyllaceae (Argophyllum), Atherospermataceae, Casuarinaceae (Gymnostoma), Cunoniaceae-Elaeocarpaceae, Ericaceae, Gnetaceae, Grisseliniaceae (Grisellinia), Meliaceae, Menispermaceae, Monimiaceae (Hedycarya), Myrsinaceae, Proteaceae (incl. Lomatia and Placospermum), Santalaceae (Notothixos), Sapindaceae, Strasburgeriaceae (Strasburgeria), and Winteraceae.

Figure 6. 1-4. Fossil Atherospermataceae: CUT-Z-CEF. 1. TLM view showing two stomatal complexes (SL0100, scale-bar = 50 µm); 2. TLM detail of single stomatal complex (SL0100, scale-bar = 20 µm). Note the distinctive outer stomatal rim; 3. SEM view of inner cuticular surface showing a single stomatal complex (S-1112, scale-bar = 20 µm); 4. SEM view of outer cuticular surface showing a single stomatal complex with prominent outer stomatal ledges (S1112, scale-bar = 20 µm).

The records of Argophyllaceae, Menispermaceae, Placospermum and Notothixos are the first of these families and genera for New Zealand. For the Argophyllaceae and Notothixos at least, these are the first known fossil records.

Figure 7. 1-8. Fossil Atherospermataceae: CUT-Z-CFA. 1. TLM view showing stomatal complexes and a massivelythickened trichome attachment scar (SB1373, scale-bar = 50 µm); 2. TLM detail of single stomatal complex (SB1373, scale-bar = 20 µm). Note the distinctive outer stomatal rim; 3. TLM view showing stomatal complexes (SL2960, scalebar = 50 µm); 4. TLM detail of single stomatal complex (SL2960, scale-bar = 20 µm). Note the distinctive outer stomatal rim; 5. TLM view showing stomatal complexes (SL0304, scale-bar = 50 µm); 6. TLM detail of single stomatal complex (SL0304, scale-bar = 20 µm). Note the distinctive outer stomatal rim; 7. SEM view of outer cuticular surface showing a single stomatal complex with prominent outer stomatal ledges surrounded by a discontinuous rim (S-1096, scale-bar = 20 µm); 8. SEM view of inner cuticular surface showing a single stomatal complex. Note granular texture of subsidiary cell periclinal walls compared with epidermal cells (S-1096, scale-bar = 20 µm).

With the exception of Cunoniaceae-Elaeocarpaceae, Ericaceae, Grisseliniaceae, Myrsinaceae, and Winteraceae, which occur in the south of New Zealand today, the fossils indicate a more southerly range extension in the Early Miocene than today.

Figure 8. 1-8. Fossil Atherospermataceae: CUT-Z-CFC, and CUT-Z-CGB. 1. CUT-Z-CFC, TLM view showing stomatal complexes and a massively-thickened trichome attachment scar (SL0066, scale-bar = 50 µm); 2. CUT-Z-CFC, TLM detail of single stomatal complex (SL0066, scale-bar = 20 µm); 3. CUT-Z-CFC, SEM view of outer cuticular surface showing stomatal complexes with prominent outer stomatal ledges (S-1108, scale-bar = 20 µm); 4. CUT-Z-CFC, SEM view of inner cuticular surface showing a single stomatal complex (S-1108, scale-bar = 20 µm); 5. CUT-Z-CGB, TLM view showing stomatal complexes and a massively-thickened trichome attachment scar (SL0088, scale-bar = 50 µm); 6. CUT-Z-CGB, TLM detail of single stomatal complex (SL0088, scale-bar = 20 µm). Note the distinctive outer stomatal rim; 7. CUT-Z-CGB, SEM view of inner cuticular surface showing a single stomatal complex (S-1111, scalebar = 20 µm); 8. CUT-Z-CGB, SEM view of outer cuticular surface showing a single stomatal complex (S-1111, scalebar = 20 µm).

This evidence of extended range along with a previously published high diversity of Lauraceae and conifers is probably the result of warmer conditions despite the fossil localities lying at about 50ºS in the Early Miocene – about 5 degrees further south than today.

Figure 9. 1-8. Fossil Atherospermataceae: CUT-Z-JIF and CUT-Z-ECG. 1. CUT-Z-JIF, TLM view showing stomatal complexes and a massively-thickened trichome attachment scar (SB0851, scale-bar = 50 µm); 2. CUT-Z-JIF, TLM detail of single stomatal complex (SB0851, scale-bar = 20 µm); 3. CUT-Z-JIF, SEM view of outer cuticular surface showing stomatal complexes and (just left of centre) a trichome attachment scar (S-319, scale-bar = 0.1 mm); 4. CUT-Z-JIF, SEM view of inner cuticular surface showing a single stomatal complex (S-319, scale-bar = 10 µm); 5. CUT-Z-ECG, TLM view showing stomatal complexes (SL1954, scale-bar = 50 µm); 6. CUT-Z-ECG, TLM detail of single stomatal complex (SL1954, scale-bar = 20 µm); 7. CUT-Z-ECG, SEM view of inner cuticular surface showing a single stomatal complex (S-1073, scale-bar = 20 µm); 8. CUT-Z-ECG, SEM view of outer cuticular surface showing a single stomatal complex (S-1073, scale-bar = 10 µm).

Argophyllum and Strasburgeria are evidence of a biogeographical link with New Caledonia, where they are now restricted. The plants were components of rainforest vegetation growing in microthermal to mesothermal temperatures.

Figure 13. 1-8. Fossil Proteaceae: CUT-P-EHA and CUT-P-EHJ. 1. CUT-P-EHA, TLM view showing stomatal complexes and (upper left) a multi-cellular trichome attachment scar. Note how epidermal cells are partially obscuring parts of some stomatal complexes (SL1680, scale-bar = 50 µm); 2. CUT-P-EHA, TLM detail of single stomatal complex (SL1680, scale-bar = 20 µm); 3. CUT-P-EHA, SEM view of inner cuticular surface showing a single stomatal complex (S-1056, scale-bar = 20 µm); 4. CUT-P-EHA, SEM view of outer cuticular surface showing a single stomatal complex with striae over the subsidiary cells (S-1056, scale-bar = 20 µm); 5. CUT-P-EHJ, TLM view showing stomatal complexes and multi-cellular trichome attachment scars (SL1682, scale-bar = 50 µm); 6. CUT-P-EHJ, TLM detail of single stomatal complex and two multi-cellular trichome attachment scars (SL1682, scale-bar = 20 µm); 7. CUT-P-EHJ, SEM view of inner cuticular surface showing stomatal complexes and (top right) a trichome attachment scar (S-1057, scale-bar = 20 µm); 8. CUT-P-EHJ, SEM view of outer cuticular surface showing stomatal complexes and (upper left) a trichome attachment scar (S-1057, scale-bar = 20 µm).
… Read more

And many more figures.

End-Triassic fluctuations in atmospheric CO2 concentration reconstructed by the use of stomatal frequency analysis

Changing CO2 conditions during the end-Triassic inferred from stomatal frequency analysis on Lepidopteris ottonis (Goeppert) Schimper and Ginkgoites taeniatus (Braun) Harris

by Bonis N. R., Van Konijnenburg-van Cittert J. H. A., Kürschner W. M. (2010)

N. R. Bonis, a J. H. A. Van Konijnenburg-Van Cittert, ab W. M. Kürschner, a

Palaeoecology, Institute of Environmental Biology, Faculty of Science, Utrecht University, Laboratory of Palaeobotany and Palynology, Budapestlaan 4, 3584 CD Utrecht, The Netherlands

Netherlands Centre for Biodiversity Naturalis, PO Box 9517, 2300 RA Leiden, The Netherlands

===

 In Palaeogeography, Palaeoclimatology, Palaeoecology 295: 146-161 – https://doi.org/10.1016/j.palaeo.2010.05.034 –

https://www.sciencedirect.com/science/article/pii/S0031018210003214

Abstract

End-Triassic fluctuations in atmospheric carbon dioxide (CO2) concentration were reconstructed by the use of stomatal frequency analysis on a single plant species: the seedfern Lepidopteris ottonis (Goeppert) Schimper.

Stomatal index showed no distinct intra- and interpinnule variation which makes it a suitable proxy for past relative CO2 changes. Records of decreasing stomatal index and density from the bottom to the top of the Rhaetian–Hettangian Wüstenwelsberg section (Bavaria, Germany) indicate rising CO2 levels during the Triassic–Jurassic transition.

Additionally, stomatal frequency data of fossil ginkgoalean leaves (Ginkgoites taeniatus(Braun) Harris) suggest a maximum palaeoatmospheric CO2 concentration of 2750 ppmv for the latest Triassic.

Stomata in fossil Ceratozamia


Plate 2
1–8. Ceratozamia hofmannii Ettingsh., Osek, drill core Os 16, depth 79.2 m, North Bohemia, Czech Republic,uppermost lower Miocene (NM G 9465)
1. Outer surface of abaxial cuticle with openings of stomatal crypts, SEM micrograph, scale bar = 20 μm
2. Inner view of stoma, showing inner lamellae, subsidiary cells and adjacent cell pattern, scale bar = 20 μm
3. Inner view of stoma, showing inner lamellae, scale bar = 10 μm
4. Outer surface of adaxial cuticle, scale bar = 100 μm
5. Inner surface of abaxial cuticle with stomata and cell patterns over intercostal areas, scale bar = 100 μm
6. Adaxial cuticle in transmitted light, showing characteristic pattern of short and long cell structure,scale bar = 100 μm
7. Abaxial cuticle in transmitted light with stomata and rows of short cells, scale bar = 100 μm
8. Overall view of abaxial cuticle with distinctly demarcated costal and intercostal areas, scale bar = 300 μm
9. Ceratozamia hofmannii Ettingsh., adaxial cuticle, duplicate preparation from holotype (NHML),scale bar = 100 μm
10. Ceratozamia floersheimensis (Engelhardt) Kvaček, abaxial cuticle from specimen shown in Pl. 1, fig. 7,scale bar = 100 μm

New fossil records of Ceratozamia (Zamiaceae, Cycadales) from the European Oligocene and lower Miocene 

by Kvacek Z. (2014)

ZLATKO KVAČEK

Charles University in Prague, Faculty of Science, Institute of Geology and Palaeontology, Albertov 6, CZ 12843 Praha 2, Czech Republic

===

by Acta Palaeobotanica 54(2): 231–247 – DOI: 10.2478/acpa-2014-0012 –

New_fossil_records_of_Ceratozamia_Zamiaceae_Cycada (1).pdf


Plate 3
1, 2. Ceratozamia microstrobila Vovides & J.D. Rees, cult. MBC
1. Adaxial epidermis with long thick-walled cells and narrower rows of short cells
2. Abaxial epidermis with amphicyclic stomata and rows of long and short narrower cells
3, 4. Ceratozamia mexicana Brongn., cult. K
3. Adaxial epidermis with long thick-walled cells and narrower rows of short cells
4. Abaxial epidermis with incompletely amphicyclic stomata and rows of long and short narrower cells
5, 6. Ceratozamia sabatoi Vovides et al., Querétaro, coll. Schutzmann BD 8665.2
5. Adaxial epidermis with long thick-walled cells and narrower rows of short cells
6. Abaxial epidermis with monocyclic stomata and rows of long and short narrower cells
7, 8. Ceratozamia norstogii D. W. Stev., cult. MBC
7. Adaxial epidermis with long cells and rows of short cells
8. Abaxial epidermis with incompletely amphicyclic stomata and rows of long and short narrower cells
9, 10. Ceratozamia hofmannii Ettingsh., Osek, Os16-2
9. Adaxial epidermis with long cells and rows of short cells
10. Abaxial epidermis with incompletely amphicyclic stomata and rows of long and short narrower cells
11, 12. Zamia paucijuga Wieland, coll. Schutzman S-55, Mexico
11. Adaxial epidermis with uniform pattern of narrow elongate cells
12. Abaxial epidermis with incompletely amphicyclic stomata and rows of nondifferentiated cells
13, 14. Dioon edule Lindl., cult. PRC
13. Adaxial epidermis with rows of shorter quadrangular and longer thick-walled cells
14. Abaxial epidermis with incompletely amphicyclic, deeply sunken stomata in crypts and rows of nondifferentiated cells
15, 16. Microcycas calocoma (Miq.) DC., cult. MBC
15. Adaxial epidermis with long elongate thick-walled and narrower thin-walled cells
16. Abaxial epidermis with incompletely amphicyclic stomata and rows of thick-walled and thin-walled cells

ABSTRACT

New compression leaf material of Ceratozamia (Zamiaceae) has been recognised in the EuropeanCenozoic. A leaflet of Ceratozamia floersheimensis (Engelhardt) Kvaček was recovered among unidentified mate-rial from the Oligocene of Trbovlje, former Trifail, Slovenia, housed in old collections of the Austrian GeologicalSurvey, Vienna. It is similar in morphology and epidermal anatomy to other specimens previously studied fromthe lower Oligocene of Flörsheim, Germany and Budapest, Hungary. A fragmentary leaflet assigned to C. hof-mannii Ettingsh. was recovered in the uppermost part of the Most Formation (Most Basin in North Bohemia,Czech Republic) and dated by magnetostratigraphy and cyclostratigraphy to CHRON C5Cn.3n, that is, the latestearly Miocene. It yielded excellently preserved epidermal structures, permitting confirmation of the generic affin-ity and a more precise comparison with this lower Miocene species previously known from Austria (Münzenberg,Leoben Basin) and re-investigated earlier. Both the Oligocene and Miocene populations of Ceratozamia are basedon isolated disarticulated leaflets matching some living representatives in the size and slender form of the leaf-lets. Such ceratozamias thrive today in extratropical areas near the present limits of distribution of the genusalong the Sierra Madre Orientale in north-eastern Mexico, in particular C. microstrobila Vovides & J.D. Reesand others of the C. latifolia complex, as well as C. hildae G.P. Landry & M.C. Wilson (“bamboo cycad”). Theoccurrence of Ceratozamia suggests subtropical to warm-temperate, almost frostless climate and a high amountof precipitation. The accompanied fossil vegetation of both species corresponds well with the temperature regime.While the Oligocene species in Hungary probably thrived under sub-humid conditions, the remaining occur-rences of fossil Ceratozamia were connected with humid evergreen to mixed-mesophytic forests.

Stomata in Eostangeria ruzinciniana and other Cycads (Zamiaceae, Cycadophyta)

Plate 2
1–5. Eostangeria ruzinciniana (Palamarev, Petkova & Uzunova) Palamarev & Uzunova
Adaxial cuticle with dark-staining cells and a trichome base, No. 3518, × 180
Adaxial cuticle, No. 3518, × 300
Abaxial cuticle with stomata and a trichome base, (in the circle of subsidiary cells one subsidiary cell is
lacking), No. 3518, × 300
Abaxial cuticle with stomata and scattered short dark-staining cells, No. 3518, × 300
Abaxial cuticle near a costal area with stomata and scattered triangular dark-staining cells, No. 3518, × 300

Eostangeria ruzinciniana (Zamiaceae) from the Middle Miocene of Bulgaria and its relationship to similar taxa of fossil Eostangeria, and extant Chigua and Stangeria (Cycadales)

by Uzunova K., Palamarev E., Kvacek Z. (2001)

KRASSIMIRA UZUNOVA1, EMANUEL PALAMAREV2 and ZLATKO KVACˇ EK3


1 Biological Faculty, Sofia University, 8 Dragan Znakov, 1421 Sofia, Bulgaria

2 Institute of Botany, Bulgarian Academy of Sciences, 23 Acad. G. Bonchev, 1113 Sofia, Bulgaria,

3 Charles University, Faculty of Science, Albertov 6, 128 43 Praha 2, Czech Republic

===

by Acta Palaeobot. 41(2): 177–193 – 

http://bomax.botany.pl/cgi-bin/pubs/data/article_pdf?id=570

Plate 3
1–3. Chigua restrepoi D. Stevenson (D. Stevenson 693, Colombia)
Adaxial cuticle with stomata, a trichome base and many darker cells, x 100
Abaxial cuticle showing stomata with incomplete circles of partly long triangular subsidiary cells (one subsidiary
cell lacking) and trichome bases, × 180
Details of stomata (cuticle not stained), × 300
4–5. Chigua bernalii D. Stevenson (R. Bernal, G. Galeano & D.L. Restrepo 1189, Colombia)
Adaxial cuticle with dark-staining cells and a stoma, × 100
Abaxial cuticle showing stomata with partly elongate triangular subsidiary cells (polar subsidiary cells
mostly missing), and a trichome base, × 100
Zamia soconuscensis Schutzman, Vovides & Dehgan (B. Schutzman S-885, Chiapas), abaxial cuticle with
stomata, × 200

ABSTRACT

Characterisation of Eostangeria ruzinciniana (Palamarev, Petkova & Uzunova) Palamarev & Uzunova(Middle Miocene – Volhynian, Bulgaria) is augmented. The species is compared with morphologically similar
cycads: E. saxonica Barthel (Eocene of Germany), E. pseudopteris Z. Kvacˇek & Manchester (Late Palaeocene and Eocene of western USA), and the extant Chigua D. Stevenson and Stangeria T. Moore. Leaf epidermal anatomy indicates that E. ruzinciniana is closely related to other members of Eostangeria, forming with them a natural unit. Eostangeria slightly differs from Chigua (Zamioideae) in the presence of short dark-staining cells in the lower epidermis, densely toothed margins, and in the case of Eostangeria ruzinciniana by obviously persistent, non-articulated leaflets. In morphological features of the leaflets, Eostangeria resembles Stangeria (Stangeriaceae); however, the latter decidedly differs in entirely cyclocytic stomata lacking ventral lignified lamellae, coarsely striated epidermis with strongly undulate anticlines and an absence of short dark-staining cells.
A new subfamily Eostangerioideae is suggested to accommodate Eostangeria within Zamiaceae.