Verticils of Annularia are usually found as dorsi-ventral adpressions spread out on the bedding plane; leaf whorls in Annularia are either isophyllous or markedly anisophyllous.
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, leaves of Annularia galioides are of near-equal length in almost isophyllous verticils.
Verticils of Annularia fertilis have isophyllous leaf whorls, with oblong, longer leaves, with a greater length/breadth ratio.
She also noted that Annularia acicularis has anisophyllous leaf verticils, in contrast to the isophyllous verticils of Annularia radiata.
COMPARISONS: Annularia fertilis possesses isophyllous verticils with a similar number of leaves to that in Annularia radiata; however, these are oblong, with an acute, mucronate apex.
Annularia radiata has more leaves per verticil (12-16); although these leaves, like those of Annularia ramosa, are linear-lanceolate and in isophyllous verticils, they are longer.
Our analyses suggest that ancestral Gunnera was a small, sympodially branching, cauline herb, producing axes in the axils of its leaves, lacking stolons, and with isophyllous
, opposite leaves.