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Blechnum alpinum

Description

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Family Blechnaceae

Plants perennial , mostly terrestrial , occasionally on rock or epiphytic. Stems creeping to suberect or ascending , sometimes climbing [rarely arborescent ], slender to stout, dictyostelic, scaly . Leaves monomorphic or dimorphic , large and coarse , generally greater than 30 cm, often exceeding 1 m. Petiole not articulate , generally more than 2 vascular bundles arranged in arc, generally scaly at least at base . Blade often anthocyanic (reddish) when young, pinnatifid [rarely simple ] to pinnate-pinnatifid or 2-pinnate [rarely decompound ], glabrous or occasionally bearing scales or capitate glands . Rachis frequently grooved adaxially. Veins of sterile leaves generally free , rarely anastomosing, veins of fertile leaves united to form sorus-bearing secondary vein parallel to costa or costule (vascular commisure), sometimes anastomosing further. Sori elongate along secondary vein; indusia present [rarely absent], opening along costal side of fertile vein, frequently hidden by dehisced sporangia; sporangial stalk of 3 rows of cells . Spores monolete, reniform ; perine present, variously ornamented. Gametophytes green, cordate, sometimes bearing capitate hairs, antheridia and archegonia borne on lower surface.

Genera ca. 10, species ca. 250 (2 genera, 6 species in the flora ) : mostly tropical and south temperate (except Woodwardia, which is north temperate) .

Circumscription of genera is controversial, especially as to placement of those species now included in Blechnum . Characteristics holding the family together include the anastomoses of veins along the axes of the blade to form a series of areoles or a single continuous vein along which the sorus is borne, elongate sori with indusia opening toward midvein , bilateral spores, and chromosome base numbers of generally x = 28--36. Relationships of the family with both dryopteroid and athyrioid ferns have been suggested.[1]

Genus Blechnum

Plants terrestrial or rarely on rock. Stems creeping to ascending or erect , slender to stout, sometimes climbing [rarely subarborescent]; scales brown or black. Leaves monomorphic or variously dimorphic , cespitose to scattered . Blades pinnatifid to 1-pinnate, rarely simple or 2-pinnate. Rachis and costae glabrous , scaly , or hairy abaxially. Veins free , often forked . Sori borne on vascular commissures parallel to costae, 1 per side, normally uninterrupted, linear , continuous along length of costa. Spores with perine smooth to variously winged or rugose . x = 28, 29, 31, 32, 34, 36.

Species ca. 220: mostly tropical , especially Southern Hemisphere.[2]

Taxonomy

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Notes

Publishing author : Mett. Publication : Fil. Lips. 64. 1856 1856 Basionym : Blechnaceae Stegania alpina R.Br.Basionym author: (R.Br.)

Similar Species

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Members of the genus Blechnum

ZipcodeZoo has pages for 396 species, subspecies, varieties, forms, and cultivars in this genus. Here are just 100 of them:

B. acanthopodum · B. acrodontum · B. acuminatum · B. acutiusculum · B. acutum · B. adnatum · B. aggregatum · B. alpinum · B. amabile · B. ambiguum · B. andicola · B. andinum · B. angustatum · B. angustifolium · B. angustifrons · B. anthracinum · B. antillanum · B. appendiculatum (Hammock Fern) · B. araucanum · B. arborescens · B. archboldii · B. arcuatum · B. articulatum · B. asesorale · B. asperum · B. asplenioides · B. asplenoides · B. atherstoni · B. atropurpureum · B. attenuatum · B. aurantum · B. auratum · B. auratum subsp. columbiense · B. auriculatum · B. auriculatum var. genuinum · B. australe · B. australe subsp. auriculatum · B. australe var. aberrans · B. austrobrasilianum · B. bakeri · B. bamlerianum · B. banksii · B. bicolor · B. biforme · B. binervatum · B. binervatum subsp. acutum · B. binervatum subsp. fragile · B. blechnoides (Salt-Spray Fern) · B. blechnoides var. gracilipes · B. blumei · B. bolivianum · B. boreale · B. borneense · B. bradei · B. 'Brasila' · B. brasiliense (Red Brazilian Tree Fern) · B. brasiliensis · B. brassii · B. brevifolium · B. brownei · B. bruneum · B. buchtienii · B. calophyllum · B. camfieldii · B. campylotis · B. capaense · B. capense · B. capense var. acuminatum · B. capense var. minus · B. carolinianum · B. cartilagineum (Gristle Fern) · B. castaneum · B. caudatum · B. ceteraccinum · B. chambersii (Lance Water-Fern) · B. chauliodontum · B. chilense (Chilean Hard-Fern) · B. chiriquanum · B. chordatum (Chilean Hard Fern) · B. christii · B. ciliatum · B. circulatum · B. cochabambense · B. cognatum · B. colensoi · B. colombiense · B. columbiense · B. confluens · B. confusum · B. contiguum · B. corbassonii · B. corcovadense · B. cordatum · B. coriaceum · B. corralense · B. costaricense · B. crispum · B. cunninghamii · B. cycadifolium · B. dalgairnsiae

More Info

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Notes

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Contributors

Identifiers

Footnotes

  1. Raymond B. Cranfill "Blechnaceae". in Flora of North America Vol. 2. Oxford University Press. Online at EFloras.org. [back]
  2. Clifton E. Nauman "Blechnum". in Flora of North America Vol. 2. Oxford University Press. Online at EFloras.org. [back]
Last Revised: 7/2/2009