9. Dryopteris Adanson, Fam. Pl. 2: 20, 551. 1763.
Wood fern, shield fern, dryoptère [Greek drys, tree, and pteris, fern]
James D. Montgomery
Warren H. Wagner Jr.
Plants terrestrial, rarely on rock. Stems short-creeping to erect, stolons absent. Leaves monomorphic, green through winter or dying back in winter. Petiole ca. 1/4--2/3 blade length, bases swollen or not; vascular bundles more than 3, arranged in an arc, ± round in cross section. Blade deltate-ovate to lanceolate, 1--3-pinnate-pinnatifid, gradually reduced distally to pinnatifid apex, herbaceous to somewhat leathery. Pinnae not articulate to rachis, segment margins entire, crenate, or serrate, spinulose or not; proximal pinnae reduced (several pairs), same size as or enlarged relative to more distal pinnae, sessile to petiolulate, equilateral or often inequilateral with pinnules on basiscopic side longer than those on acroscopic side; costae adaxially grooved, grooves continuous from rachis to costae to costules; indument of linear to ovate scales abaxially, also sometimes with glands, blades ± glabrous adaxially. Veins free, forked. Sori in 1 row between margin and midrib, round; indusia round-reniform, attached at narrow sinus, persistent or caducous. Spores brownish, coarsely rugose or with folded wings. x = 41.
Species ca. 250 (14 in the flora): mostly in temperate Asia.
The relationships of the North American species are reasonably well understood, but species identifications are complicated by the frequent presence of hybrids in field populations. Sterile hybrids can be distinguished from fertile species by their misshapen spores and intermediate morphology. They are not included in the key, but they may be identified as to parentage by combinations of characters in the key (e.g., marginal sori for Dryopteris marginalis , narrow blades for D . cristata ). Relationships are shown in the accompanying reticulogram.
Carlson, T. J. and W. H. Wagner Jr. 1982. The North American distribution of the genus Dryopteris. Contr. Univ. Michigan Herb. 15: 141--162. Fraser-Jenkins, C. R. 1989. A classification of the genus Dryopteris (Pteridophyta: Dryopteridaceae). Bull. Brit. Mus. (Nat. Hist.), Bot. 18: 323--477. Montgomery, J. D. 1982. Dryopteris in North America. Part II. The hybrids. Fiddlehead Forum 9: 23--30. Montgomery, J. D. and E. M. Paulton. 1981. Dryopteris in North America. Fiddlehead Forum 8: 25--31. Petersen, R. L. and D. E. Fairbrothers. 1983. Flavonols of the fern genus Dryopteris: Systematic and morphological implications. Bot. Gaz. 144: 104--109. Viane, R. L. 1986. Taxonomical significance of the leaf indument in Dryopteris (Pteridophyta): I. Some North American, Macronesian and European taxa. Pl. Syst. Evol. 153: 77--105. Wagner, W. H. Jr. 1971. Evolution of Dryopteris in relation to the Appalachians. In: P. C. Holt, ed. 1971. The Distributional History of the Biota of the Southern Appalachians. Part 2. Flora. Blacksburg, Va. Pp. 147--192. [Virginia Polytechnic Inst. and State Univ., Res. Div. Monogr. 2.] Werth, C. R. 1991. Isozyme studies on the Dryopteris "spinulosa" complex. I: The origin of the log fern Dryopteris celsa. Syst. Bot. 16(3): 446--461.