8. DAVALLIA, Smith.
Rhizome usually long and creeping, paleaceous. Fronds large or small, usually compound, very variously divided, rarely simple, stipitate; texture coriaceous to membranous. Veins always free. Sori dorsal, but close to or at the margin of the frond, terminating a vein or veinlet, globose or more or less elongated. Indusium oblong or ovate to orbicular or broader than long, attached by a broad base under the sorus, its sides either free or adnate to the frond, open at the top. Sporangia numerous, stalked, girt by an incomplete vertical ring, bursting transversely.
A large genus of over 100 species, most abundant in the tropical and sub-tropical regions of the Old World, rare in America. The three species found in New Zealand are endemic. I have kept up the genus as defined in the "Synopsis Filicum," but the tendency of authors is to separate it into five or six or even more separate genera, mainly based on differences in the indusium. If these views are followed, D. Tasmani is the only one of the New Zealand species that would be retained in the restricted genus Davallia, D. novce-zealandicœ constituting the genus Leptolepia of Mettenius, and D. Forsteri falling into Odontosoria of Presl.
| Fronds 4–12 in., broadly deltoid, thick and coriaceous; ultimate segments oblong, obtuse. Indusium cup-shaped, attached by the sides as well as the base | 1. D. Tasmani. |
| Fronds about 6 in., rhomboid, subcoriaceous; ultimate segments ligulate-cuneate. Indusium pouch-shaped, attached by the sides as well as the base | 2. D. Forsteri. |
| Fronds 12–24 in., ovate-oblong to deltoid, firm but hardly coriaceous, very finely cut; ultimate segments narrow, acute. Indusium broadly ovate, attached by the base only | 3. D. novæ-zealandiœ. |
1. D. Tasmani, Cheesem. in Trans. N.Z. Inst. xxiii. (1891) 416.—Rhizome long, stout, as thick as the finger, wide-creeping, densely clothed with chestnut-brown subulate ciliated scales. Stipes strong, rigid, smooth, 3–9 in. long. Fronds 4–12 in. long, 3–9 in. broad, broadly deltoid or pentagonal, very thick and coriaceous, quite smooth and glabrous, 2–3-pinnatifid. Lower pinnæ much the largest, broadly deltoid or rhomboidal; upper narrower, ovate or lanceolate. Pinnules oblong, cut down nearly to the base into 6–9 segments; segments short, oblong, obtuse. Sori very numerous, usually one to each segment, marginal, the segment usually produced on the outer side into a stout projecting horn. Indusium narrow cup-shaped, attached by the sides as well as the base.—Field, N.Z. Ferns, 75, t. 24, f. 5; Bak. in Ann. Bot. v. (1890–91) 201.
