orbicular, attached by a central stalk, flat or convex, membranous, concealing the sorus when young. Sporangia stalked, bursting transversely, girt by an incomplete vertical ring.
A genus of about 70 species, found in most parts of the world. The New Zealand species all belong to the subgenus Polystichum, characterized by the free veins, coriaceous habit, and usually sharply toothed segments. Of the 7 species enumerated in this work, 3 are very widely distributed, 1 is American and antarctic, another extends to Fiji, the remaining 2 are endemic.
| A. Rhizome short, stout, erect. Fronds tufted at the top of the rhizome. | |
| Fronds 1–3 ft., oblong-lanceolate, coriaceous, narrowed below, 2-pinnate; segments sharply toothed. Stipes shaggy with large dark scales mixed with hairs | 1. A. aculeatum |
| Fronds 4–8in., oblong-lanceolate, coriaceous, pinnate; segments obtusely toothed. Stipes clothed with blackish-brown scales | 2. A. mohrioides. |
| Fronds 9–18 in., ovate-deltoid, rigid and coriaceous, not narrowed below, 1–2 pinnate; segments sharply toothed. Stipes clothed with narrow black scales | 3.A. Richardi. |
| Fronds 10–20 in., ovate-obloug, coriaceous, not narrowed below, 2-3 pinnate; segments obtusely toothed. Stipes clothed with large black scales margined with white. Indusium with a large black disc | 4. A. oculatum. |
| Fronds 4–12 in., oblong-lanceolate, soft and flaccid, 2-pinnate. Stipes clothed with large pale membranous scales. Indusium large, very convex | 5. A. cystostegia. |
| B. Rhizome long, creeping. Fronds distant along the rhizome. | |
| Fronds 1–3 ft., deltoid, 2–3-pinnate. Ultimate segments obtusely lobed or toothed | 6. A. capense. |
| Fronds 1–3 ft., deltoid, 2–3-pinnate. Ultimate segments with aristate teeth or lobes | 7. A. aristatum. |
1. A. aculeatum, Swartz in Schrad. Journ. ii. (1800) 37; var. vestitum, Hook. f. Handb. N.Z. Fl. 375.—Rhizome short, stout, erect or ascending, sometimes produced into an erect caudex 1–4 ft. high. Stipes 6–18 in. long, stout, erect, densely clothed with spreading scales; many of the scales large, over 1 in. long, ovate-lanceolate or subulate-lanceolate, long-acuminate, lacerate, straight or curved, glossy, black or dark-brown with a pale margin; others bristle-like or woolly, pale-ferruginous or tawny. Fronds numerous, forming a spreading crown at the top of the caudex, 1–3 ft. long without the stipes, 4–9 in. broad, oblong-lanceolate or linear-oblong, acute or acuminate, narrowed towards the base, rather coriaceous, dark-green, glabrous above when mature, under-surface more or less fibrillose, bipinnate; rhachis usually densely scaly like the stipes, but sometimes the broader scales are wanting. Primary pinnæ numerous, close-set, horizontally spreading, 2–5 in. long, ½–1 in. broad, linear-lanceolate or lanceolate, acuminate. Pinnules numerous, close, shortly stipitate, ovate-rhomboidal, unequal-sided, more or less auricled on the upper side near the base, toothed or lobed or pinnatifid, the lobes acute or pungent. Sori 6–8 to a
