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Polystichum bulbiferum

Overview

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Endangered

Threat status

Interesting Facts

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Description

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Family Dryopteridaceae

Plants perennial , terrestrial or on rock, occasionally hemiepiphytic or epiphytic. Stems creeping to erect , rarely arborescent , sometimes climbing , branched or unbranched, dictyostelic, bearing scales . Leaves circinate in bud, monomorphic or dimorphic . Petiole usually not articulate to stem, scales usually persistent at base , in cross section with 2--many roundish bundles, or bundles 2 and lunate . Blade simple to commonly 1--5-pinnate or more divided , leaf buds absent or present. Veins pinnate or parallel in ultimate segments, simple or forked , free or anastomosing, areoles sometimes with included free veinlets. Indument on blade commonly of glands , hairs , and/or scales, especially on rachis and costae abaxially. Sori borne abaxially on veins or at vein tips (but usually not marginal ), or sporangia acrostichoid and covering abaxial surface, if in discrete sori then variously shaped (round , oblong , or elongate ) ; receptacle not or only slightly elevated , with or without indusium, indusium variously linear , falcate , or reniform , sometimes hoodlike, cuplike, or round. Sporangia with stalk of 2--3 rows of cells ; annulus vertical , interrupted 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.[1]

Genus Polystichum

Plants terrestrial . Stems decumbent to erect , stolons absent. Leaves monomorphic (dimorphic in P. acrostichoides ), evergreen . Petiole 1/9--1 times length of blade , bases swollen or not; vascular bundles more than 3, arranged in an arc, ± round in cross section . 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 with acroscopic lobe ; costae adaxially grooved , grooves continuous from rachis to costae; indument of linear to lanceolate scales on costae and sometimes between veins abaxially (microscales), ± glabrous or similarly scaly adaxially (scales 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 or caducous [absent]. Spores yellow or brownish to black, with inflated folds. x = 41.

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.[2]

Habitat

Biome: Terrestrial [3].

Ecology: Occurs in low Andean forest (1,500–2,000 m ).[3].

List of Habitats :

Taxonomy

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Similar Species

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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)

More Info

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Further Reading

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Notes

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Contributors

Identifiers

Footnotes

  1. Alan R. Smith "Dryopteridaceae". in Flora of North America Vol. 2. Oxford University Press. Online at EFloras.org. [back]
  2. David H. Wagner "Polystichum". in Flora of North America Vol. 2. Oxford University Press. Online at EFloras.org. [back]
  3. Navarrete, H. & Pitman, N. 2003. Polystichum bulbiferum. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 04 February 2012. [back]
Last Revised: 7/22/2012