Discosoropteris chlupatum Pšenička, W.M.Zhou, C. K. Boyce, Frojdová et Jun Wang bis in Pšenička, Zhou, Boyce, Votočková Frojdová, Bek, Opluštil & Wang

Plant Fossil Names Registry Number: PFN003472

Act LSID: urn:lsid:plantfossilnames.org:act:3472

Authors: J. Pšenička, W. M. Zhou, C. K. Boyce, J. Votočková Frojdová & J. Wang

Rank: species

Genus:

Reference for this name: Pšenička, J., Zhou, W. M., Boyce, C. K., Votočková Frojdová, J., Bek, J., Opluštil, S. & Wang, J. (2022): Two new leptosporangiate ferns from in situ volcanic ash of the Whetstone Horizon (Kladno Formation, Pennsylvanian), Pilsen Basin, Czech Republic. – Review of Palaeobotany and Palynology 299: 1–25.

Page of description: 2

Illustrations or figures: pls I-VIII

Types

Original diagnosis/description

Frond at least tripinnate. Rachis densely covered bymulticellular uniseriate trichomes across all orders. Trichomes from antepenultimate
and penultimate rachises tend to clump into bundles. Penultimate rachis has C-shaped xylem band. Tracheids with scalariform wall thickenings and reticulate pitting. Fertile and vegetative pinnules of the same shape and size. Three to four sterile pinnules are proximal in each fertile ultimate pinna. Pinnules elongately oval, constricted at the base, and separated into 6–7 lobes with the largest lobe on the acroscopic side; their alternate insertion is perpendicular on the ultimate rachis. Margin gently dentate. Midvein prominent and nearly straight over proximal half of pinnule. Secondary veins bifurcate twice or three times, terminating individually in marginal teeth. Pinnules bearing uniseriatemulticellular trichomes on both pinnule sides. Cuticle - adaxial side: Cells of costal field oval or brick-shaped and cells of intercostal field tetragonal having undulate anticlinal walls. Cuticle - abaxial side: Cells of costal field elongate and tetra-polygonal having straight anticlinal walls. Papillae present on abaxial side irregularly scattered over the entire surface with a higher concentration around trichome bases and stomata. Anomocytic stomata irregularly scattered over the intercostal field.

Reproductive characters: Leptosporangia grouped into massive discshaped hemispherical sori situated on the lower side of fertile pinnule. Sori consist of up to 60 annulate sporangia, between the midvein and pinnulemargin. Sporangia immersed in tangle of uniseriatemulticellular trichomes. Annulate sporangia ovoid or pyriform, very shortly stalked, 0.2–0.32 mm long and 0.12–0.22 mm wide. Sporangial wall consists of four different types of cells: 1) Thick-walled cells of semi-apical annulus, 2) thick-walled apical polygonal cells, 3) thick-walled cell of dehiscence area, and 4) thin-walled ordinary cells. Microspores are trilete laevigate, microgranulate, microspinate to finely reticulate.

Etymology

The name is derived from the Czech word for hairy rachis “chlupatý”.

Stratigraphy

Carboniferous, Pennsylvanian
Whetstone Horizon of the Radnice Member, Kladno Formation; Pennsylvanian, lowermost Moscovian (late Duckmantian).

Locality

Czech Republic
Doubrava locality (near Nýřany); Pilsen Basin (Carboniferous of Central Bohemia).