Woodsiaceae |
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Plants epipetric, or occasionally terrestrial; roots blackish, wiry, inserted radially, non-proliferous; rhizomes short-creeping, horizontal to suberect, commonly unbranched, bearing scales; rhizome scales lanceolate, nonclathrate, the margins glandular or eglandular, without distinct pubescence, entire to denticulate or ciliate, the teeth when present formed by two adjacent cells, or not; leaves green and not covered in mucilage during any stage of development, usually spirally arranged, monomorphic, closely spaced, bearing scales and hairs, the hairs catenate or terete, sometimes gland-tipped (e.g., Woodsia mollis (Kaulf.) J. Sm.), sometimes the scales forming a reduction series that terminates in broad-based, catenate, hair-like scales (e.g., Woodsia mollis); petioles stramineous, castaneous or dark purple throughout, or proximally darkened, the base thin, not forming trophopods, persistent, usually forming a thick mantle of old petiole bases, without conspicuous aerophores, in some species with a petiolar articulation, the articulation usually proximal (e.g., Woodsia ilvensis (L.) R. Br.) or just below the lamina; petiolar vascular bundles two, the bundles with hippocampiform-shaped xylem, distally uniting to form a single U-shaped bundle; laminae herbaceous, 1-pinnate to 2-pinnate-pinnatifid, usually broadest in the middle, the base with a series of reduced pinnae or not, the apex non-conform, the leaf marginal cells differentiated into nodulose hyaline cells or not; pinna axes not articulate, sessile or slightly petiolate; rachis axes sulcate adaxially, lacking a free central ridge, the grooves not continuous; veins free, terminating before the leaf margin, the vein endings usually expanded and forming hydathodes; sori dorsal along veins, sub-terminal, or terminal (e.g., Woodsia elongata Hook.), round, indusiate; soral receptacle distinctly flat; indusia basal, composed of a series of scalelike or filamentous segments or sometimes sac-like globose, glandular, pubescent, or not; sporangia with stalks two or three cells wide in the middle; spores monolete, non-chlorophyllous, tan or brown, the perispore echinate, tuberculate, or with broad folds or narrow crests, these sometimes forming a reticulum; chromosome base numbers x = 33 (Woodsia manchuriensis Hook.; Kurita, 1965), 38, 39, or 41 (Manton, 1950; Brown, 1964). The family Woodisaceae is interpreted here as having one genus, Woodsia, and about 35 species. In the past, these species have sometimes been placed in four different genera, one of the genera being Woodsia. When fertile, members of the Woodsiaceae are easily diagnosed by the unique basal indusium composed of multiple scale-like or filamentous segments (occasionally as a single globose structure enclosing the sorus), which is unique among ferns. Many Cyatheaceae (in Cyatheales; see Fig. 1) have basal scale-like indusia, but these are generally more robust, are often spherical or cup-shaped, and do not consist of multiple segments. Some other taxa in Cyatheaceae have sori protected by scaly indument (e.g., Sphaeropteris subsect. Fourniera (J. Bommer ex Fourn.) P.G. Windisch); in these cases the scales resemble those of the lamina whereas in Woodsia they do not. Sterile leaves of Woodsiaceae, however, are not as easily characterized. When present, the petiolar articulation is a powerful diagnostic character, because it is unique in Eupolypods II, and rare outside of this clade. However, its utility is hindered by its absence from most species. Nonetheless, all species tend to accumulate large mats of persistent petiole bases, which are characteristic. In addition, the combination of 1-pinnate to 2-pinnate-pinnatifid leaves with sessile or short-petioled pinnae, laminae usually bearing scales and hairs (that are not acicular), and veins that terminate before the leaf margin in hydathodes serve for identifying Woodsiaceae. Sterile plants of Cystopteris can appear surprisingly similar to those of Woodsia, however, they can be distinguished by having veins that reach the leaf margin. Global distribution of Woodsiaceae. CAUTION: GBIF records include introduced and cultivated plants. In addition, GBIF may follow a different taxonomic interpretation from that adopted in the treatments presented here. For all three reasons, the distribution shown may differ from statements presented here about a taxon's native distribution.
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