| ** Under-surface of frond green. | |
| Trunk 20–50 ft. Fronds 8–20 ft., coriaceous; stipes and rhachis conspicuously muricate beneath. Fertile segments lobulate or pinnatifid | 2. C. medullaris. |
| Trunk 20–40 ft. Fronds 6–18 ft., not so coriaceous; stipes and rhachis rough but hardly muricate, clothed with yellow-brown tomentum. Fertile segments obscurely serrate, not lobulate | 3. C. Milnei. |
| Trunk 8–20 ft. Fronds 6–10 ft., almost membranous; stipes and rhachis slightly asperous, clothed with strigose hairs above. Fertile segments lobulate or pinnatifid | 4. C Cunninghamii. |
1. C. dealbata, Swartz, Syn. Fil. 140, 356.—Trunk 10–30 ft. high, seldom more, 9–18 in. diam. at the base, clothed above the middle with the short light-brown bases of the old stipites. Fronds numerous, horizontally spreading, 6–12 ft. long, 2–4 ft. broad, 2–3-pinnate, subcoriaceous, green or yellow-green above, pure-white beneath from a coating of deciduous powder. Stipes rather slender, slightly asperous, clothed at the base with shining dark-brown linear scales, elsewhere (together with the rhachis and costæ) more or less covered with yellow-brown deciduous tomentum, becoming almost glabrous when old. Primary pinnæ 1–1½ ft. long, oblong, acuminate; secondary 2–4 in., linear-lanceolate, acuminate or almost caudate, deeply pinnatifid or pinnate towards the base. Segments or pinnules ¼–½ in. long, linear-oblong, acute or subacute, more or less falcate, serrate. Sori small, globose, copious, but often confined to the lower half of the segments. Indusium small, membranous, only covering the sorus in a very early stage, persistent at the base as a shallow cup.—A. Rich. Fl. Nouv. Zel. 77, t. 10; A. Cunn. Precur. n. 226; Raoul, Choix, 38; Hook. Sp. Fil.i. 27; Hook. f. Fl. Nov. Zel. ii. 7; Handb. N.Z. Fl. 349; Hook. and Bak. Syn. Fil. 26; Thoms. N.Z. Ferns, 28; Field, N.Z. Ferns, 45, t. 10, f. 2. C. tricolor, Col. in Trans. N.Z. Inst. xv. (1883) 304. (?)Hemitelia falciloba, Col. in Trans. N.Z. Inst. xxiv. (1892) 394. Polypodium dealbatum, Forst. Prodr. n. 454.
North and South Islands, Chatham Islands: Abundant in woods from the North Cape to Foveaux Strait. Sea-level to 2000 ft. Ponga; Silver Tree-fern.
Perhaps the most generally distributed of the New Zealand tree-ferns. It can usually be identified at a glance by the milk-white under-surface of the fronds, although individual specimens are occasionally seen in which the under-surface is obscurely glaucous or even quite green. Very young plants are always green beneath; the white first appearing in irregular patches, giving the under-surface a curious piebald appearance. Outside New Zealand it occurs in Lord Howe Island, and a barren plant collected at Penang is assumed to be the same.
2. C. medullaris, Swartz, Syn. Fil. 140, 366.—Trunk 20–50 ft. high or even more, in old plants furnished at the base with a hard and thick conical buttress formed of densely compacted aerial root-
