or on rock, occasionally hemiepiphytic
or epiphytic. Stems creeping
, rarely arborescent
, sometimes climbing
, branched or unbranched, dictyostelic, bearing scales
. Leaves circinate
in bud, monomorphic
usually not articulate
to stem, scales usually persistent
, in cross
with 2--many roundish bundles, or bundles 2 and lunate
to commonly 1--5-pinnate or more divided
, leaf buds
absent or present. Veins pinnate or parallel in ultimate
segments, simple or forked
or anastomosing, areoles sometimes with included
free veinlets. Indument
on blade commonly of glands
, and/or scales, especially on rachis and costae abaxially. Sori borne abaxially on veins or at vein
(but usually not marginal
), or sporangia acrostichoid
and covering abaxial
surface, if in discrete sori then variously shaped (round
, or elongate
) ; receptacle not or only slightly elevated
, with or without indusium, indusium variously linear
, or reniform
, sometimes hoodlike, cuplike, or round. Sporangia with stalk
of 2--3 rows
; annulus vertical
by stalk. Spores all of 1 kind, usually not green (except Matteuccia, Onoclea ), oblong or reniform in outline, monolete, variously ornamented (often broadly winged
), 64 per sporangium (32 in apogamous spp.
) . Gametophytes green, aboveground, cordate, glabrous
or often bearing glands or hairs; archegonia and antheridia borne on lower surface, antheridia 3-celled.
Genera ca. 60, species perhaps exceeding 3000 (18 genera, 79 species in the flora ) : worldwide.
The family Dryopteridaceae has been variously circumscribed; it is here delimited in a manner similar to that of R. M. Tryon and A. F. Tryon (1982) but with the inclusion of Nephrolepis . In many works, the family has gone under the illegitimate name Aspidiaceae. Some authorities define Dryopteridaceae more narrowly, to exclude Athyrium, Deparia, Diplazium, Cystopteris, and Gymnocarpium (Athyriaceae or Woodsiaceae), Woodsia (Woodsiaceae), Lomariopsis (Lomariopsidaceae), Nephrolepis (Nephrolepidaceae or Davalliaceae), Onoclea and Matteuccia (Onocleaceae), and Ctenitis and Tectaria (Tectariaceae) . Characteristics holding Dryopteridaceae (as circumscribed here) together include the bilateral , monolete spores, often broadly winged perispore, absence of needlelike hairs, scaly stem and petiole bases, abaxial (nonmarginal) sori, base chromosome number of 40 or 41 (also 38 and 39 in Woodsia, 37 in Onoclea, 42 in Cystopteris ), and usually indusiate sori. Loss of indusium, dimorphism , areolate venation , and reduced blade dissection have occurred repeatedly along many evolutionary lines in Dryopteridaceae, and in general these characteristics are often not very useful in delimiting genera or assessing intergeneric relationships .
In some genera, especially Phanerophlebia and Polystichum, the blade bears very narrow scales (sometimes called microscales) that resemble uniseriate hairs. These scales may be only one or two cells wide. Every intergradation exists between these filiform microscales and more typical, wider scales, and the two types are the same color, generally tan to brownish. Microscales are probably not homologous with true hairs, which may be either unicellular or multicellular , uncolored or sometimes reddish (as in Tectaria and Ctenitis ), glandular (as in Woodsia ) or not. Hairs in Dryopteridaceae, if present at all, are generally readily distinguishable from the needlelike, transparent ones found in Thelypteridaceae.
. Stems decumbent
, stolons absent. Leaves monomorphic
in P. acrostichoides ), evergreen
1/9--1 times length
swollen or not; vascular bundles
more than 3, arranged in an arc, ± round
. Blade linear-lanceolate to broadly lanceolate, 1--3-pinnate, gradually reduced distally to pinnatifid
apex, somewhat leathery to leathery. Pinnae not articulate
to rachis, segment or pinna margins
spinulose-toothed (except P. lemmonii ) ; proximal
pinnae (several pairs) usually gradually reduced, sessile to short-petiolulate, bases usually inequilateral
; costae adaxially grooved
continuous from rachis to costae; indument
to lanceolate scales on costae and sometimes between veins abaxially (microscales), ± glabrous
or similarly scaly
forming loosely tangled network
over blade and sori in P. dudleyi ). Veins free, forked
, rarely ( P. imbricans ) anastomosing. Sori in 1 row
(to several) between midrib
and margins, round (confluent
, covering abaxial
surface in P. acrostichoides ) ; indusia peltate, persistent
[absent]. Spores yellow or brownish to black, with inflated
Species ca. 180: worldwide.
The mating systems of Polystichum seem to be highly outcrossing (P. S. Soltis and D. E. Soltis 1987; P. S. Soltis et al. 1989) ; hybrids are frequent where two or more species occur. Sterile hybrids are discussed under one of their putative parents.
Sterile hybrids are best recognized by their misshapen sporangia, which produce little black dots at the end of the season instead of forming the fuzzy brown bump typical of sori after spores have been expelled. In many cases the intermediacy and robustness of hybrids make them stand out as odd. At least one or two hybrid plants are to be expected in large, mixed populations. The allopolyploids, having hybrid origins , present particular problems. They exhibit the Vavilov effect: allopolyploids tend to resemble one of their parental species when they grow with, or in the habitat typical of, that species (D. S. Barrington et al. 1989).
In the flora there are six diploids, five tetraploids , one hexaploid , and three species whose chomosome number is unknown. Relationships among the diploids are generally not very close; that is, each is probably more closely related to a species outside the flora than to one of the other species in the flora. The exception to this is the group composed of Polystichum acrostichoides, P. imbricans, and P. munitum. Polystichum acrostichoides appears to share a Tertiary common ancestor with P. munitum, and P. imbricans is more recently derived from P. munitum. All of the polyploid species are fertile allopolyploids. One of these species ( P. braunii ) is also involved in the formation of the hexaploid P. setigerum (see below).
Relationships among Polystichum Species
Allopolyploid Presumed Originating Crosses: andersonii kwakiutlii × munitum californicum dudleyi × imbricans or dudleyi × munitum kruckebergii lemmonii × lonchitis scopulinum lemmonii × imbricans or lemmonii × munitum setigerum braunii × munitum
The morphological similarity among Polystichum species may make identification difficult, particularly among the species with more divided leaves. The keys presented here are designed for mature , typical individuals. Some of the characters mentioned in the keys and descriptions require the use of a microscope. The microscales (small trichomes that occur on the abaxial leaf surface of all species and adaxially in some) are best observed by peeling them off with cellophane tape and mounting the tape on a slide , sticky side up, under a coverslip. The tape can also be used to lift off the components of the sori. Polystichum acrostichoides, P. andersonii, P. lemmonii, and P. munitum are known to have sclereid clusters in their pith . Polystichum imbricans lacks such clusters, and data are not available for the other species.
- Whittaker & Margulis,1978
- Haeckel, 1866
- Cavalier-Smith, 1981
- Sinnott, 1935 ex Cavalier-Smith, 1998
- Vascular Plants
- Kenrick & Crane, 1997, Nom. Nud.
- Cronquist et al.
- Ching, 1965, nom. cons.
- Wood Fern Family
- A.W. Roth, 1799, nom. cons.
- [Sword fern, Christmas fern, holly fern [Greek poly, many, and stichos, row, presumably in reference to the rows of sori on each pinna]
- Specific epithet:
- Botanical name: - Polystichum grande Fee
- Specific epithet: grande - Fee
- Genus: Polystichum () - A.W. Roth, 1799, nom. cons. - [Sword fern, Christmas fern, holly fern [Greek poly, many, and stichos, row, presumably in reference to the rows of sori on each pinna]
- Family: Dryopteridaceae () - Ching, 1965, nom. cons. - Wood Fern Family
- Order: Polypodiales () - Link
- Class: Polypodiopsida () - Cronquist et al.
- Infraphylum: Moniliformopses () - Kenrick & Crane, 1997, Nom. Nud.
- Subphylum: Euphyllophytina ()
- Phylum: Tracheophyta () - Sinnott, 1935 ex Cavalier-Smith, 1998 - Vascular Plants
- Subkingdom: Viridaeplantae () - Cavalier-Smith, 1981
- Kingdom: Plantae () - Haeckel, 1866 - Plants
Members of the genus Polystichum
ZipcodeZoo has pages for 61 species, subspecies, varieties, forms, and cultivars in this genus:
P. acrostichoides (Christmas Fern) · P. acrostichoides f. crispum (Christmas Fern) · P. acrostichoides f. demittens (Christmas Fern) · P. acrostichoides f. gymnosorum (Christmas Fern) · P. acrostichoides f. incisum (Christmas Fern) · P. acrostichoides f. ligulatum (Christmas Fern) · P. acrostichoides f. multifida (Christmas Fern) · P. acrostichoides f. recurvatum (Christmas Fern) · P. acrostichoides f. spathiforme (Christmas Fern) · P. acrostichoides f. ventroperaferens (Christmas Fern) · P. acrostichoides var. acrostichoides (Christmas Fern) · P. acrostichoides var. crispum (Christmas Fern) · P. acrostichoides var. incisum (Christmas Fern) · P. acrostichoides var. lonchitoides (Christmas Fern) · P. aculeatum (Hard Shield Fern) · P. aleuticum (Aleutian Holly Fern) · P. andersonii (Anderson Holly-Fern) · P. bonseyi (Bonsey's Hollyfern) · P. braunii (Braun's Holly-Fern) · P. braunii f. alaskense (Braun´s Holly Fern) · P. braunii var. andersonii (Braun´s Holly Fern) · P. calderonense (Monte Guilarte Hollyfern) · P. californicum (California Sword-Fern) · P. dudleyi (Dudley's Sword Fern) · P. echinatum (Rusty Swordfern) · P. falcatum var. falcatum (Japanese Holly Fern) · P. hagenahii (Hagenah's Polystichum) · P. haleakalense (Island Swordfern) · P. hillebrandii (Hillebrand Holly-Fern) · P. imbricans (Narrow-Leaf Swordfern) · P. imbricans curtum (Narrowleaf Swordfern) · P. imbricans imbricans (Narrowleaf Swordfern) · P. imbricans subsp. curtum (Narrowleaf Swordfern) · P. kruckebergii (Kruckeberg's Hollyfern) · P. kwakiutlii (Kwakiutl's Hollyfern) · P. lemmonii (Lemmon's Hollyfern) · P. lonchitis (Hollyfern) · P. makinoi (Makinoi's Holly Fern) · P. microchlamys (Attu Holly Fern) · P. munitum (Sword Fern) · P. munitum f. flabellatum (Western Sword Fern) · P. munitum f. inciso-serratum (Western Sword Fern) · P. munitum f. nudatum (Western Sword Fern) · P. munitum subsp. solitarium (Western Sword Fern) · P. muricatum (West Indian Hollyfern) · P. neolobatum (Long-Eared Holly Fern) · P. ovatopaleaceum (Polystichum) · P. platyphyllum (Flatleaf Hollyfern) · P. polyblepharum (Holly Fern) · P. polystichiforme (Antilles Hollyfern) · P. potteri (Potter's Polystichum) · P. proliferum (Mother Shield Fern) · P. rhizophyllum (Tailed Hollyfern) · P. scopulinum (Eaton's Hollyfern) · P. setiferum (Alaskan Fern) · P. setiferum Plumosomultilobum Group (Soft-Shield Fern) · P. setiferum 'Congestum' (Dwarf Soft Shield Fern) · P. setiferum 'Divisilobum' (Soft Shield Fern) · P. setigerum (Alaska Holly Fern) · P. tripteron (Trifid Holly Fern) · P. tsus-simense (Korean Rock Fern)
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- Wagner, D. H. 1979. Systematics of Polystichum in western North America north of Mexico. Pteridologia 1: 1--64.
- Wagner, W. H. Jr. 1973. Reticulation of holly ferns (Polystichum) in the western United States and adjacent Canada. Amer. Fern J. 63: 99--115.
- Welsh, S. L. 1974. Anderson's Flora of Alaska and Adjacent Parts of Canada. Provo.
- Yatskievych, G., D. B. Stein, and G. J. Gastony. 1988. Chloroplast DNA evolution and systematics of Phanerophlebia (Dryopteridaceae) and related fern genera. Proc. Natl. Acad. Sci. U.S.A. 85: 2589--2593.
- Brands, S.J. (comp.) 1989-present. The Taxonomicon. Universal Taxonomic Services, Zwaag, The Netherlands. Accessed January 9, 2012.
Accessed through GBIF Data Portal November 27, 2007:
- Missouri Botanical Garden, Missouri Botanical Garden
- Biodiversity Heritage Library NamebankID: 3418156
- Global Biodiversity Information Facility Taxonkey: 15460000
- Globally Unique Identifier: urn:lsid:ipni.org:names:17354690-1
- Zipcode Zoo Species Identifier: 1101366