pteridosperm


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Related to pteridosperm: seed fern

pteridosperm

(ˈtɛrɪdəˌspɜːm)
n
1. (Plants) any extinct seed-producing fernlike plant of the group Pteridospermae. Also called: seed fern
2. (Palaeontology) any extinct seed-producing fernlike plant of the group Pteridospermae. Also called: seed fern
[C19: from Greek pteris a fern + -sperm]

seed′ fern`


n.
any of various fossil plants of the order Lyginopteridales (or Cycadofilicales) that had fernlike leaves and reproduced by means of seeds. Also called pteridosperm.
[1925–30]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.pteridosperm - an extinct seed-producing fernlike plant of the order Cycadofilicales (or group Pteridospermae)pteridosperm - an extinct seed-producing fernlike plant of the order Cycadofilicales (or group Pteridospermae)
gymnosperm - plants of the class Gymnospermae having seeds not enclosed in an ovary
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References in periodicals archive ?
Here I describe an upright tree of Macroneuropteris scheuchzeri rooted above the Point Aconi Coal in the Middle Pennsylvanian Sydney Mines Formation of Nova Scotia--the first example of an autochthonous pteridosperm described in the literature.
Some pteridosperm stems and fructifications with particular reference to the Medullosae.
Cuticular analysis appears to be especially valuable for elucidating pteridosperm scrambling/climbing aids (cf.
From Sydney Coalfield, one pteridosperm seed attached to foliage Of Neuropteris flexuosa is known (Zodrow and McCandlish 1980) which emphasizes the rarity of attached female organs to determinable foliage.
The evidence, such as it is, of preserved alethopterid biomass favours that the undetermined alethopterid foliage was borne on the interpreted 5-7 m tall pteridosperm tree.
Fossil orbicules are also found in pteridosperm pollen organs (e.
Evidence for pollination-drop mechanism in Paleozoic pteridosperms.
8h) with minor contributions from lycopsids (Lepidodendron and Lepidophloios), sphenopsids (Calamites), and possible tree ferns and pteridosperms (Ielpi et al.
Evidence for a pollination-drop mechanism in Paleozoic pteridosperms.
Late Gzhelian pteridosperms with callipterid foliage of the Donets Basin, Ukraine.
Drifted lycopsid plants predominate in the basal limestones, whereas overlying siltstones and sandstones contain a mixed suite of drifted gymnosperms (cordaitaleans), sphenopsids (primarily calamiteans), pteridosperms and putative progymnosperms (Falcon-Lang 2003a).