Fossil plants, Vol. 3 : $b A text-book for students of botany and geologySeward, A. C. (Albert Charles)
Science
Fossil plants, Vol. 3 : $b A text-book for students of botany and geology
Seward, A. C. (Albert Charles)
Paleobotany
Renault founded this Permian species as _Antholithus permiensis_[357]
on a specimen from Lodève; it consists of an incomplete inflorescence
6·4 cm. long bearing four lateral branches with stalks 1·5 to 2 cm.
long terminated by clusters of small oval bracts 5 mm. long. Renault
compares the fossil with the recent Conifers _Glyptostrobus_ and
_Tsuga_, but it exhibits a much closer resemblance to _Schützia
anomala_.
The genus _Schützia_, originally described from Permian strata, is
recorded also from Westphalian strata in North Africa[358] as well
as from Lower Carboniferous rocks in Scotland. The data at present
available are insufficient to determine the morphological nature of the
fertile branches: the evidence adduced by Goeppert in support of the
occurrence of seeds is not convincing and the interpretation of the
bract-like appendages is still an open question; they may have formed
a cupular investment to seeds, but in the Scotch species the general
appearance rather suggests that they may be microspore-bearing organs
comparable with those of _Codonotheca_[359]. There are no adequate
grounds for supposing _Schützia_ to belong to the Coniferales, a view
advanced by some authors; it is much more likely to represent the
fertile shoots of a Pteridosperm.
=WHITTLESEYA=. Newberry.
The genus _Whittleseya_, referred by many authors to the _Ginkgoales_,
has no substantial claim to be regarded as allied to that group: its
position is still uncertain, but the recent discovery of fertile
specimens suggests the probability of a relationship to _Potoniea_ and
an identification of Whittleseya as another form of microsporophyll of
a Pteridosperm.
[Illustration: Fig. 428.
A, C. _Whittleseya elegans_. A, single leaflet, from Pennsylvania.
(After Lesquereux; ⅚ nat. size.) C, diagrammatic sketch of part
of a leaflet showing the teeth, the striated texture of the
carbonised layer, and the vein-like markings on a lower
surface. (After Thomas; enlarged.)
B. _Whittleseya brevifolia_. (After White; the smaller figure ⅚ nat.
size.)]
The generic name was given by Newberry[360] to some leaves, or possibly
leaflets, originally described by C. Whittlesey from the Coal Measures
of Ohio. Whittleseya is represented by species from several North
American localities[361] in Ohio, Pennsylvania, Arkansas, Nova Scotia,
and New Brunswick[362]; it occurs in Silesia and has recently been
found in the English Coal Measures[363]. The genus is confined to Upper
Carboniferous strata.
The leaves are fairly thick; the lamina is oblong, cuneate, broadly
triangular or linear, usually rounded and truncate (fig. 428, A,
C), generally dentate at the distal end, the proximal portion being
gradually or abruptly contracted and occasionally prolonged into a
short pedicel. The veins or ribs are parallel to the sides of the
lamina and except near the base unbranched.
_Whittleseya elegans_ Newberry.
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