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Paleozoic Seed Studies: On the Genus Hexapterospermum

Thomas N. Taylor
American Journal of Botany
Vol. 53, No. 2 (Feb., 1966), pp. 185-192
Stable URL: http://www.jstor.org/stable/2440087
Page Count: 8
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Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Paleozoic Seed Studies: On the Genus Hexapterospermum
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Abstract

The petrified Paleozoic seed Hexapterospermum is discussed. A new species, H. delevoryii, is described from several seed specimens collected from Middle Pennsylvanian deposits in southern Illinois. The new species is radially symmetrical; approximately 2.5 cm long and 1.3 cm in diam at the widest region. Six primary ribs extend from the integument and give the seed the configuration of a hexagon when sectioned transversely. A thin plate of cells is present at the region of the commissure in each of the ribs. Additional features, not included in the original description of the genus, are described including the occurrence of a pollen-receiving mechanism consisting of a collar-like nucellar extension surrounding a central column. Relationships with other Paleozoic seeds are also discussed.

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