Higher Plants in the Rhynie chert

The Higher Plants found in the Rhynie chert are assumed to differ so much from each other and from any other plant that every one has been given another genus name. (Hence, the species name is omitted here, for simplicity.)
None of them has been found elsewhere. It is not known whether they represent a widespread flora of that time or an endemic flora possibly consisting of Silurian relics. This contributes to the fascination emanating from the Rhynie chert.
Until now, 7 species have been found. They are listed below in the sequence of their discovery.

Aglaophyton
( = Rhynia major)

twice re-named

Most common plant in the Rhynie chert,
cause of some confusion and errors up to now,
unique creeping mode,
shoots about 4mm across, forking,
often with "hollow straw" aspect owing to persistent fraction of tissue;
spindle-shaped twisted sporangia at the top.

Aglaophyton cross-section of unique aspect

Rhynia

More similar to Aglaophyton than to any other plant,
smaller in all parts, shoots about 1-2mm across,
often with well preserved tissue,
occasionally in densely spaced stands.

Horneophyton

originally named Hornea after the palaeobotanist
J. Horne

Forking shoots with odd-shaped branching sporangia at the top,
stout rhizome consisting of fused tubers persisting in the soil like onions (see picture, 4mm wide) after wilting of the shoots.

Asteroxylon

named after the "star-shaped" xylem cross-section

Most complex plant in the Rhynie chert
with roots (or root-like shoots ?), small leaf-like enations,
appearance similar to some clubmoss,
big central strand with odd-shaped cross-section with scalariform tracheid wall pattern,
surrounding tissue nearly always decayed,
sporangia laterally attached, rarely seen.

Nothia

named after the conspicuous hill "Tap o' Noth" overlooking Rhynie

Creeping rhizome, upright forking shoots,
central strand forking much earlier than shoot,
misinterpreted as Asteroxylon branches until 1961,
surface with bulges, sporangia laterally attached.

Trichopherophyton

means "hairy plant",

family zosterophylls

Creeping rhizome, upright shoots with curled-up tip,
central strand forking far below branching of shoot,
branching often asymmetrical and peculiar,
upper parts beset with stiff pointed hairs,
sporangia laterally attached.

Ventarura

means "windy field" after the Windyfield farms near the chert subcrop,
family zosterophylls

Creeping rhizome, upright shoots with curled-up tip,
upper parts with unique tube of rot-resistant cells,
tisue within and without nearly always decayed,
sporangia laterally attached.

Another zosterophyll ?

Sporangium laterally attached, short spines ( ? poorly preserved fragment ).