Fróðskaparrit - 01.01.1963, Page 81

Fossil Metasequoia From Mikines, Faroe Islands
87
with the rock in question which is so crowded with plant
impressions, that the shale becomes extremely fissile. There*
fore some pieces could easily have been Iost.
Some other specimens (No. 7, 10, A, B, C, D and G)
(Pl. 1, figs. 2, 3) also contain parts of long shoots with
or without short shoots attached. For instance, specimens
A, B, C show short shoots, disposed in pairs, while the
specimen no. G shows only a fragment of a long shoot.
The long shoots carry leaves between the nodes. These
leaves are remote, linear, short petiolate and obtusely rounded
terminally and basally. The Ieaves have relatively large
decurrent bases and are opposite, or a Ieaf may be oppo=
site a short shoot. Their average dimensions are: length
10 mm, width: 1,7 mm. The axes of the long shoots show
the impressions of more or less distinct, obliquely decurrent
leaf bases which successively overlap from right and left
in the manner characteristic of Metasequoia. In addition,
the long shoots show opposite short shoots or their scars.
But the phyllotaxy is best studied on the short shoots.
Well preserved short shoots (which are numerous in
the collection) demonstrate that the leaves are opposite
and apparently distichous (i. e. no. 11) (Pl. 1, 2). Just as
observed on the recent Metasequoia glyptostroboides Hu &.
Cheng, the pattern of the leaf bases demonstrates that the
distichous arrangement is only apparent and that originally
it was decussate. This can be definitely confirmed by
studying the well preserved specimens in this collection
(No. 11, 13) (Pl. 1, figs. 1, 3, 4). The characteristic zig*
zag pattern on the impression of the axis of the short
shoots results from the obliquely decurrent bases of the
opposite leaves which are decussately arranged. The leaves
of the short shoots are closely spaced, short petiolate, linear
and obtusely rounded terminally and basally. They have
strong, obliquely decurrent bases which enclose the axis
and even overlap most of the base of the opposite leaf.
In a succession of opposite leaf pairs this successive over*