Studies on a lower carboniferous flora from kingswood near Pettycur, Scotland. II. Phacelotheca, a new synangiate fructification of pteridospermous affinities

Abstract

Phacelotheca pilosa gen. et sp. nov. is described from Kingswood, a locality of Upper Visean age near Pettycur. The fructification was borne laterally on a stalk and dichotomizes several times in a cruciate arrangement. Presumed reduction and overtopping has resulted in aggregation of the synangia which are arranged in tiers at the extremity of foreshortened branch axes. Each synangium is composed of two to four elongate sporangia with longitudinal and ventral dehiscence. Each sporangium is supplied at its base by a single vascular strand. The spores are small, spherical and trilete with a wall differentiated into a nexine and sexine; the sexine is granular to granular-alveolar. In many features, Phacelotheca pilosa resembles pollen organs attributed to Lyginopteridaceae. The current status of the genus Telangium is discussed.