''Blechnum'', known as hard fern, is a
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
fern
The ferns (Polypodiopsida or Polypodiophyta) are a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissue ...
s in the family
Blechnaceae, subfamily Blechnoideae, according to the
Pteridophyte Phylogeny Group classification of 2016 (PPG I).
[ Two very different circumscriptions of the genus are used by different authors. In the PPG I system, based on Gasper et al. (2016),][ ''Blechnum'' is one of 18 genera in the subfamily Blechnoideae, and has about 30 species.][ Other sources use a very broadly defined ''Blechnum'' s.l., including accepting only two other genera in the subfamily. The genus then has about 250 species.][ In the PPG I circumscription, the genus is mostly neotropical, with a few southern African species.
]
Description
Plants in the genus ''Blechnum'' (as circumscribed in the PPG I classification) are mainly terrestrial or grow on rocks; few are epiphyte
An epiphyte is a plant or plant-like organism that grows on the surface of another plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphyt ...
s. Their rhizome
In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and Shoot (botany), shoots from its Node (botany), nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from ...
s may be upright or creeping and have scales with entire margins or at most a few very small teeth. They generally form stolon
In biology, a stolon ( from Latin ''wikt:stolo, stolō'', genitive ''stolōnis'' – "branch"), also known as a runner, is a horizontal connection between parts of an organism. It may be part of the organism, or of its skeleton. Typically, animal ...
s, which is a characteristic of the genus. The sterile and fertile fronds are usually of the same form or at most slightly different. The blades of the fronds are of one colour and are usually pinnatisect or unipinnate, rarely entire. The leaf veins are usually free, dividing one to three times, each ending near the frond margin in an enlarged tip. The sori have indusia (scale-like coverings).[
]
Species
Using the PPG I circumscription, , the ''Checklist of Ferns and Lycophytes of the World'' accepted the following species and hybrids.[
*'' Blechnum anthracinum'' R.C.Moran
*'' Blechnum appendiculatum'' Willd.
*'' Blechnum arcuatum'' J.Rémy ex Fée
*'' Blechnum areolatum'' V.A.O.Dittrich & Salino
*'' Blechnum asplenioides'' Sw.
*'' Blechnum auriculatum'' Cav.
*'' Blechnum australe'' L.
*'' Blechnum austrobrasilianum'' de la Sota
* ''Blechnum'' × ''caudatum'' Cav.
* ''Blechnum'' × ''confluens'' Schltdl. & Cham.
* ''Blechnum'' × ''falciculatum'' C.Presl
*'' Blechnum gracile'' Kaulf.
*'' Blechnum gracilipes'' (Rosenst.) M.Kessler & A.R.Sm.
*'' Blechnum guayanense'' A.Rojas
*'' Blechnum hastatum'' Kaulf.
*'' Blechnum heringeri'' Brade
*'' Blechnum laevigatum'' Cav.
*'' Blechnum lanceola'' Sw.
* ''Blechnum'' × ''leopoldense'' (Dutra) V.A.O.Dittrich & Salino
*'' Blechnum longipilosum'' V.A.O.Dittrich & Salino
*'' Blechnum ludificans'' Herter
*'' Blechnum malacothrix'' Maxon & Morton
*'' Blechnum meridense'' Klotzsch
*'' Blechnum occidentale'' L.
* ''Blechnum'' × ''pampasicum'' de la Sota & M.L.Durán
*'' Blechnum polypodioides'' Raddi
*'' Blechnum punctulatum'' Sw.
*'' Blechnum tomentosum'' M.Kessler & A.R.Sm.
]
References
Further reading
* Huxley, A., ed. (1992). ''New RHS Dictionary of Gardening''. Macmillan
* Moore, D. M. (1983). ''Flora of Tierra del Fuego''
External links
Trees and shrubs in the Andes of Ecuador: ''Blechnum''
{{Taxonbar, from=Q2049575
Blechnaceae
Fern genera
Taxa named by Carl Linnaeus