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.

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Published by

Willem Van Cotthem

Honorary Professor of Botany, University of Ghent (Belgium). Scientific Consultant for Desertification and Sustainable Development.

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