Blechnum | |
---|---|
Blechnum occidentale in cultivation at Lotusland, Montecito, California | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Division: | Polypodiophyta |
Class: | Polypodiopsida |
Order: | Polypodiales |
Suborder: | Aspleniineae |
Family: | Blechnaceae |
Subfamily: | Blechnoideae |
Genus: | Blechnum L. |
Type species | |
Blechnum occidentale | |
Species | |
Blechnum, known as hard fern, is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, according to the Pteridophyte Phylogeny Group classification of 2016 (PPG I). [1] Two very different circumscriptions of the genus are used by different authors. In the PPG I system, based on Gasper et al. (2016), [2] Blechnum is one of 18 genera in the subfamily Blechnoideae, and has about 30 species. [1] 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. [3] In the PPG I circumscription, the genus is mostly neotropical, with a few southern African species.
Plants in the genus Blechnum (as circumscribed in the PPG I classification) are mainly terrestrial or grow on rocks; few are epiphytes. Their rhizomes may be upright or creeping and have scales with entire margins or at most a few very small teeth. They generally form stolons, 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). [2]
Using the PPG I circumscription, as of December 2019 [update] , the Checklist of Ferns and Lycophytes of the World accepted the following species and hybrids. [4]
Onoclea is a genus of plants in the family Onocleaceae, native to moist habitats in eastern Asia and eastern North America. They are deciduous ferns with sterile fronds arising from creeping rhizomes in spring, dying down at first frost. Fertile fronds appear in late summer. Depending on the authority, the genus contains one to five species.
Blechnaceae is a family of ferns in the order Polypodiales, with a cosmopolitan distribution. Its status as a family and the number of genera included have both varied considerably. In the Pteridophyte Phylogeny Group classification of 2016, the family has 24 genera, and excludes genera placed in the separate family Onocleaceae. The family is divided into three subfamilies, including Blechnoideae s.s. Alternatively, the entire family may be treated as the subfamily Blechnoideae s.l. of a very broadly defined family Aspleniaceae, and include genera others place in Onocleaceae.
Lomaria is a genus of ferns belonging to the family Blechnaceae.
Struthiopteris spicant, syn. Blechnum spicant, is a species of fern in the family Blechnaceae, known by the common names hard-fern or deer fern. It is native to Europe, western Asia, northern Africa, and western North America. Like some other species in the family Blechnaceae, it has two types of leaves. The sterile leaves have flat, wavy-margined leaflets 5 to 8 millimeters wide, while the fertile leaves have much narrower leaflets, each with two thick rows of sori on the underside.
Neoblechnum is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, with a single species Neoblechnum brasiliense, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily; the species is then known as Blechnum brasiliense. It is called Brazilian dwarf tree fern, red Brazilian tree fern, and red dwarf tree fern.
Struthiopteris is a genus of ferns belonging to the family Blechnaceae, subfamily Blechnoideae.
Austroblechnum is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.
Blechnopsis is a small genus of ferns in the family Blechnaceae, subfamily Blechnoideae, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.
Cranfillia is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.
Diploblechnum is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.
Lomaridium is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.
Lomariocycas is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.
Oceaniopteris is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.
Parablechnum is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.
Blechnidium is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, with a single species Blechnidium melanopus, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.
Brainea is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, with a single species Brainea insignis, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.
Cleistoblechnum is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, with a single species Cleistoblechnum eburneum, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.
Icarus is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, with a single species Icarus filiformis, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.