Caryanthus sp.

Heřmanová, Zuzana & Kvaček, Jiří, 2012, A New Record Of The Genus Caryanthus From The Cretaceous Of South Bohemia (Czech Republic), Acta Musei Nationalis Pragae Series B 68 (1 - 2), pp. 47-50 : 49

Species Caryanthus sp.

The specimen described here is currently the only known Caryanthus inflorescence / infructescence. It is 1.4 mm long and 0.8 mm broad ( Text-fig. 2A ), and consists of three bisexual, epigenous postanthetic flowers / fruits. Two of them are in lateral positions, separated by about 45° from each other. They surround the central flower, which is positioned slightly higher in the inflorescence than the other two ( Text-figs 2A, B ). Each flower / fruit is supported by several bracts, but the number of bracts is uncertain due to the preservation of the fossil. The flowers / fruits have tepals united basally forming a hypanthium. Fruits in the inflorescence are closely spaced. The flowers / fruits are distinctly epigynous and have a hypanthium characterized by three distinct grooves on each side. The androecium of each flower consists of six stamens. Only basal parts of the filaments are preserved. The gynoecium is bicarpellate, bearing two free styles in the apical part ( Text-fig. 2E ). Epidermal cells in the apical part of the gyneceum show sinusoid anticline walls. The surface of the fruit is covered with small irregular thick-walled cells ( Text-fig. 2C ); sometimes round trichome bases occur. Stomata are very small and sunken ( Text-fig. 2G ). Two guard cells are surrounded by probably 6 cells; this number is uncertain due to the preservation of the fossil.

Figures

Text-fig. 2. Caryanthus sp., no. F03286, locality Zliv-Řídká Blana A – Inflorescence, three bisexual flowers / fruits, central flower inserted slightly higher than the two lateral ones, scale bar 0.5 mm; B – Lateral flowers arranged at an angle of about 45˚ relative to each other, hp. – hypanthium with grooves, scale bar 0.5 mm; C – Epidermal cells of hypanthium, scale bar 0.1 mm; D – Detail of epidermal cells, scale bar 50 µm; E – Lateral flower, basal parts of six filaments and basal parts of two anthers styles, f – filaments, s – styles, scale bar 0.3 mm; F – Central flower, scale bar 0.3 mm; G – Stoma, scale bar 30 µm.