Lindsaea viridis Colenso

Rhizomes erect to short-creeping, up to 30 mm long (in herbarium specimens), 1.5–2 mm diameter, with stipes closely inserted; bearing scales. Rhizome scales narrowly ovate, 2–5 mm long, 0.2–0.5 mm wide, red-brown or golden brown. Fronds monomorphic, 40–400 mm long, laxly arching or pendent. Stipes 10–140 mm long, purple-brown or red-brown, glabrous. Rachises purple-brown or red-brown, becoming pale brown distally, narrowly winged distally, glabrous. Laminae 2-pinnate to 3‑pinnate-pinnatifid, narrowly elliptic or narrowly ovate, tapering to a pinnate apex, 30–300 mm long, 8–80 mm wide, bright green on both surfaces, herbaceous, glabrous. Primary pinnae in 7–20 pairs below terminal pinna, widely spaced especially proximally, arising at a narrow angle to the rachis and often overlapping, ovate or narrowly ovate; the longest below the middle, 5–90 mm long, 3–24 mm wide, apices acute or obtuse, bases short-stalked, divided into secondary pinnae. Secondary pinnae gradually decreasing in length along each primary pinna to the distal end; the longest secondary pinnae elliptic, 3–22 mm long, 1.5–11 mm wide, apices obtuse, bases stalked, sometimes divided into tertiary segments. Tertiary pinnae narrowly obovate, 4–7 mm long, 1–4 mm wide, apices truncate, bases stalked or adnate. Sori oblong or broader than long; indusia extending laterally 1–3 mm, more or less straight, free margin entire or slightly toothed.

Lindsaea viridis is recognised by its monomorphic fronds, purple-brown stipes and rachises, and narrowly elliptic to narrowly ovate laminae that are 2-pinnate to 3-pinnate-pinnatifid. The primary pinnae arise at a narrow angle to the rachis and often overlap. The ultimate segments are narrowly obovate and truncate. The indusia are oblong or slightly wider than long, and straight rather than curved.

Lindsaea viridis is a terrestrial fern that grows in dark podocarp and broadleaved forest, on damp banks and rock faces, on rocks and boulders in streams, on river banks, beside waterfalls, and on road cuttings, often with mosses. It is an uncommon species, most frequently found above c. 100 m.

n = c. 88 (Brownlie 1961).