Ptisana fraxinea (Sm.) Murdock

Plants terrestrial. Stems large, erect, to 200 mm in diameter, to 300 m tall, often forming plantlets near the base; roots fleshy. Fronds caespitose, arching, to 2.8 m long, up to 12 per plant; stipe terete, with persistent fleshy stipules and a basal pulvinus, to 1.7 m long, to 35 mm in diameter, sparsely and minutely tuberculate towards the base, also with simple uniseriate or branched non-glandular hairs, and short-stalked, filiform, many-branched scales; lamina to 2-pinnate, paripinnate or imparipinnate, ovate, to 1.1 m long, to 1.52 m wide, with up to 10 pinna pairs; rachis adaxially flattened, narrowly winged towards the apex, sparsely tuberculate and sparsely set with scales similar to those on the stipe; pinnae petiolate, petiole to 61 mm long, alternate, 1-pinnate, oblong-acute, to 85 mm long, to 310 mm wide, with up to 20 pinnule pairs; pinna-rachis with a basal pulvinus, adaxially shallowly sulcate, narrowly winged towards the apex, initially set with indumentum similar to that on the stipe, becoming glabrous later; pinnules petiolate, petiole to 3 mm long, alternate, dark green, firmly herbaceous, oblong-acuminate, basiscopically broadly cuneate, acroscopically broadly cuneate to dimidiate, unevenly serrate to crenate, glabrous, to 170 mm long, to 19 mm wide; costa adaxially raised, shallowly sulcate; aerophores occur as scattered short lines laterally and abaxially along the stipe and rachis, and a continuous line ventral of the secondary rachis wing between the pinnules. Venation simple or forked once, free, ending in the margin in the teeth. Synangia elongate, to 1.5 mm long, submarginal, usually on the anadromous vein branches. Spores ellipsoidal, monolete or trilete, rugate, exospore up to 37 µm long.