keys to the vascular plants of east texas - Botanical Research ...

340 DENNSTAEDTIACEAE
AA genus of 14 species of North America, Central America, Mediterranean Europe, and e Asia
(Cranfill 1993b). Some authorities (e.g., Nelson 2000) attribute the name chain fern “to the conspicuous
netted, chain-like areoles that parallel both sides of the mid-vein on the lower sides of
the pinnae and most pinnules, and impart a distinctive, chain-like appearance to the sori.
These ‘chains’ are easily seen without magnification, especially when held up to light …”
(Named for Thomas Jenkinson Woodward, 1745–1820, English botanist)
REFERENCES: Correll 1956, 1966a.
1. Leaves conspicuously dimorphic, the pinnae of fertile leaves contracted and linear in comparison
with the much wider lanceolate pinnae of the sterile leaves; sterile blades 1-pinnatifid, with
a wing of blade tissue several mm wide along much (at least upper half ) of the rachis; pinnae
themselves not pinnatifid, sometimes sinuate, the margins serrulate ________________________ W. areolata
1. Leaves monomorphic or nearly so, the pinnae of fertile and sterile leaves essentially the same;
blades 1-pinnate, with no leaf tissue along the rachis; pinnae deeply pinnatifid with entire
margins _______________________________________________________________________ W. virginica
Woodwardia areolata (L.) T. Moore, (with a network, checkered), NETTED CHAIN FERN, CHAIN
FERN, NARROW-LEAF CHAIN FERN. Sterile leaves few, 40–58 cm long; pinnae of sterile leaves in 7–
12 alternate pairs, 1–2.5 cm wide, the veins anastomosing into 2 or more rows of areoles (= small
vein-enclosed areas) between midvein and margin; fertile blades with sori nearly completely
covering surface of blade. Low, wet, usually sandy areas; Pineywoods and n Gulf Prairies and
Marshes w to Fannin Co. (BRIT) in Red River drainage and Bastrop (Turner et al. 2003), Freestone
(BAYLU), Milam, and Van Zandt (TAES) cos. near w margin of Post Oak Savannah; also n
edge of Gulf Prairies and Marshes; e U.S. from NY s to FL w to IL, OK, and TX. Sporulating Mar–
Nov. This species has sometimes been segregated into the genus Lorinseria [as L. areolata (L.) C.
Presl]. The sterile leaves resemble those of Onoclea (subopposite pinnae with entire margins),
except W. areolata usually has alternate pinnae with serrulate margins.
Woodwardia virginica (L.) Small, (of Virginia), VIRGINIA CHAIN FERN. Leaves numerous, 50–100
cm long; pinnae in 12–23 pairs, the middle pinnae 1–3.5 cm wide, the veins anastomosing to
form a single row of areoles near midvein; rachis straw-colored, sometimes darkly so; sori covering
only a small part of the blade surface. Low areas; Pineywoods and n edge of Gulf Prairies
and Marshes w to Bastrop, Lee (TAMU), Gonzales (Turner et al. 2003), and Milam (Correll 1956)
cos. on w margin of Post Oak Savannah; se Canada and e U.S. from ME s to FL w to IL, AR, and
TX. Sporulating Apr–Dec. According to Nelson (2000), this species is sometimes “confused at a
glance with Osmunda cinnamomea, with which it is sometimes found, but distinguished at
some distance by the dark brown base of the petiole, mostly darker rachis, and by the fronds
being well spaced rather than clump forming.”
DENNSTAEDTIACEAE Lotsy
BRACKEN OR CUPLET FERN FAMILY
AAs currently recognized, the Dennstaedtiaceae is a cosmopolitan but mostly tropical family
of ca. 20 genera and ca. 400 species (Cranfill 1993a). It has been variously circumscribed to include
as few as 8 genera or in other cases nearly half the genera of higher ferns (Mickel 1973).
Family name from Dennstaedtia, CUP FERN, a cosmopolitan but mostly tropical genus of ca. 70
species. (Named for August Wilhelm Dennstaedt, 1776–1826, German botanist, physician, and
director of the Belvedere Garden)
FAMILY RECOGNITION IN THE FIELD: the single East TX species is a terrestrial plant with large
leaves with 3 main divisions, each of these being 2-pinnate-pinnatifid; sori linear, along margins
of the ultimate leaf segments (= smallest subdivisions of leaf) with the leaf margins recurved
over sori to form a false indusium.
REFERENCES: Mickel 1973; Kramer 1990b; Cranfill 1993a; Wolf 1995.