verticil

1 (fragmentary verticil associated with Calamostachys sp.

Leaves of Asterophyllites lycopodioides are less curved and pass beyond the internode to touch the base of the next verticil.

2, representing only a fragment of leaf verticil, and pl.

Leaves of Asterophyllites lycopodioides are shorter and less arched; they pass beyond the node above to touch the base of the next verticil.

Verticil showing leaves with a strongly marked vein.

Incomplete verticil showing the long, oblanceolate leaves characteristic of this species.

REMARKS: Annularia and Asterophyllites incorporate small Calamites-type articulate axes bearing leaf verticils at each articulation (node).

Internodes 2.25-3 mm apart, bearing closely spaced verticils that overlap slightly in spread-out preservation.

DESCRIPTION: Ultimate axes apparently smooth, about 1 mm wide, with internodes 25 mm apart, bearing overlapping verticils with 14-16 isophyllous leaves, united at the base so as to form an annulus.

1), shows verticils composed of 14-16 isophyllous leaves, 7 to 14 mm long, with acute, mucronate apices.

In addition, Annularia latifolia shows a tendency towards anisophylly; this is not apparent in the leaf verticils of the holotype of Annularia fertilis.

Verticils on ultimate branches spaced at a little more than leaf length or slightly touching.

Matthew's variety was considered by Bell (1944) to fit the range of leaf length of Annularia latifolia; however, the verticils of the latter are anisophyllous and its leaves are widest in their upper third.

COMPARISONS: Annularia sphenophylloides has anisophyllous verticils with a larger number of leaves (12 to 18) that are spatulate, with a distinct mucron on the rounded apex.

DESCRIPTION: Ultimate axes up to 2.5 mm wide, with internodes 20-25 mm long, bearing slightly overlapping verticils. Verticils with 22-24 leaves, of unequal length, lying in the same plane as the axis and united at the base so as to form an annulus.