Rarer Calamite cone species Calamostachys tuberculata - poor but not common !

Description

My specimens are genuine and will be delivered with a "Certificate of authenticity, age and origin"  and scientific papers allowing plant identification !!!
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Specimen
:
R
are calamite cone
Calamostachys tuberculata
( STERNBERG 1825 ) WEISS 1884
!
Locality:
All detailed data will be provided with the specimen
Stratigraphy:
Upper Carboniferous - Upper Pennsylvanian / Westphalian B
Age:
ca. 310 Mya
Matrix dimensions:
ca.
7,5 x 5,0 x 2,0 cm ( white square on pictures is 1,0 x 1,0 cm )
Description:
Rare Calamite spore cone:
Calamostachys tuberculata
( STERNBERG 1825 ) WEISS 1884
Systematic:
Phylum:        Tracheophyta
Division:       Gymnospermatophyta
Class:           Equisetinae
Order:          Calamitales
Family:         Calamariaceae
Genus:         Calamostachys
Species:
Calamostachys tuberculata
( STERNBERG 1825 ) WEISS
Calamostachys
represents the reproductive organ of
cone
-shaped fructifications and peltate sporophylls growing of the Calamite tree ( mother plant -
Calamites sp.
preserved on specimen). These cones have jointed axes and are composed of whorls of alternating sterile leaves and sporangia. Like cones of modern trees, the cones of the Calamite tree swelled and opened up as they matured.
The trunks of
Calamites
had a distinctive segmented, bamboo-like appearance and vertical ribbing. The branches, leaves and cones were all borne in whorls. The leaves were needle-shaped, with up to 25 per whorl.
Their trunks produced secondary xylem, meaning they were made of wood. The vascular cambium of
Calamites
was
unifacial
, producing secondary xylem towards the stem center, but not secondary phloem.
The stems of modern horsetails are typically hollow or contain numerous elongated air-filled sacs.
Calamites
was similar in that its trunk and stems were hollow, like wooden tubes. When these trunks buckled and broke, they could fill with sediment. This is the reason pith casts of the inside of
Calamites
stems are so common as fossils.
Calamites
is a genus of extinct arborescent (tree-like) horsetails to which the modern horsetails (genus
Equisetum
) are closely related.
Unlike their herbaceous modern cousins, these plants were medium-sized trees, growing to heights of more than 30 meters (100 feet). They were components of the understories of coal swamps of the Carboniferous period.
Annularia
are the leaf whorls of an extinct horsetail. They would have grown on plants with stems like
Calamites
. A genus of fossil plants; star-leaf: so called from the stellated disposition of the leaves around the branches. They abound in the coal measures, and are believed to be the branches of the
Calamites
or
Calamodendron.