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]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

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]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun 1. [画像: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
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
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References in periodicals archive ?
Although diversity decreased towards the Griesbachian (basal Early Triassic) the Gymnosperms continued dominating the vegetation mosaic shared with pteridosperm. Cuticles recovered from the uppermost white sandstone beds of the Chhidru Formation resemble those of the peltasperm Lepidopteris, which also had been associated with Cycadopites and other younger groups.
Permo-Triassic climate change and faunal turnover in the Salt and Surghar ranges, Northern Pakistan
Architecture of the upper Carboniferous pteridosperm frond Macroneuropteris macrophylla.
A revision of Annularia and Asterophyllites species from the lower Westphalian (Middle Pennsylvanian) of the Maritime Provinces of Canada
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.
A Macroneuropteris scheuchzeri tree preserved in growth position in the Middle Pennsylvanian Sydney Mines Formation, Nova Scotia, Canada
This is followed by a rather coarse volcanic ash band with large fragments of the presumed pteridosperm Alethopteris brevis Weiss.
El permico inferior de Valdeviar (Sevilla), SW de Espana: geologia historica de la cuenca e implicaciones climaticas y paleogeograficas
Some pteridosperm stems and fructifications with particular reference to the Medullosae.
The telome theory
Less commonly recorded are medullosan pteridosperm axes, rare foliage (Alethopteris sp.) and seeds (Trigonocarpus cf.
Stratigraphy and sedimentology of early Pennsylvanian red beds at Lower Cove, Nova Scotia, Canada: the Little River Formation with redefinition of the Joggins Formation
Cuticular analysis appears to be especially valuable for elucidating pteridosperm scrambling/climbing aids (cf.
How Paleozoic vines and lianas got off the ground: on scrambling and climbing Carboniferous--early Permian pteridosperms
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.
Foliar forms of Macroneuropteris scheuchzeri (Pennsylvanian, Sydney Coalfield, Nova Scotia, Canada)
Fossil orbicules are also found in pteridosperm pollen organs (e.g., Taylor, 1976; Stidd, 1978).
Orbicules in angiosperms: morphology, function, distribution, and relation with tapetum types
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.
The "medullosalean forest" at the Lloyd Cove Seam (Pennsylvanian, Sydney Coalfield, Nova Scotia, Canada)
Among different plant groups Pteridosperms were also trying to coope with theenvironment as shown by their morphographic features like radial monosaccate construction helpful in floating of pollen during dispesal , leathery saccus construction and saccus enclosing the corpus from all sides for the protection of microgametophte .
MONOSACCATE POLLEN FROM EARLY TRIASSIC STRATA (MIANWALI FORMATION) WESTERN SALT RANGE, PAKISTAN
Evidence for pollination-drop mechanism in Paleozoic pteridosperms. Science 198: 1251-1252.
Degradome and secretome of pollination drops of Ephedra

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