Christella Leveille

Terrestrial ferns of moderate to large size, sometimes small. Rhizome an erect or ascending, less often long-creeping, radially symmetric caudex, dictyostelic, almost always bearing narrow scales with many superficial and marginal acicular hairs. Fronds long-stipitate, the stipe with 2 vascular bundles at the base uniting upward into a single U-shaped vascular strand, lamina pinnate with crenate to deeply pinnately lobed pinnae, in almost all species several pairs of basal pinnae gradually reduced and almost always auricled on the acroscopic side, aerophores at bases of pinnae not swollen, margins entire, midribs of pinnae grooved above, but the grooves not confluentwith rachis groove, erect, unicellular, acicular hairs and abundant on abaxial surface, mostly alsoon adaxial surface, short capitate hairs often present, thick orange-red glandular hairs sometimes present below, sessile spherical glands lcaking, veins in a pinnate group in each pinna-lobe or crenation, mostly at least the basal pair of each group anastomosing to form an excurrent vein terminating in the sinus membrane, the remaining veinlets simple, free, terminating in the magin above the sinus membrane, in a few deeply lobed species all veins free. Sori round, indusiate, rarely exindusiate, medial or distal on the veins; sporangi on a 2-seriate stalk bearing an elongate unicellular glandular hair for an acicular hair) or not, the annulus longitudinal interrupted. Spores monolete, dark, nearly black, variously tuberculate or ridged, without thin wings.

Sect. Christella: plants of normal size, not restricted to limestone; veins nearly always anastomosing, at least the basal pair to form an excurrent vein terminating in the sinus membrane, rarely all veins free; hairs on sporangia stalks elongate-glandular. (Paleotropics).

Sect. Leptochristella: reduced plants (pinnae mostly less than 4 cm long of limestome; veins free or infrequently anastomosing; hairs on sporangium stalks, if present, acicular. (Papuasia).

Sect. Pelazoneuron: plants of normal size, not restricted to limestone; veins always free, the basal acroscopic vein terminating the sinus membrane, the basiscopic vein of the next group terminating above the sinus, rarely the two casually anastomosing in some pinnae to form an excurrent vein; hairs on sporangia stalks acicular. (Africa and Neotropics).

Key modified ex Holttum 1981, F1. Males. ser. 2, 1:553 and 1977, Allertonia 1:216.

Species in Papuasia