326 articles
Diphasiastrum
Diphasiastrum, ground cedars, is a genus of clubmosses (Lycopodiaceae) published by Holub in 1975, with flattened fan-like branches, underground mycorrhizal gametophytes, x=23, and extensive hybridization in Central Europe; sometimes synonymized with Lycopodium.
Diphasiastrum digitatum
Diphasiastrum digitatum (Dill. ex A. Braun) Holub, southern ground-cedar or fan clubmoss, is a North American clubmoss (Lycopodiaceae) with flat fan-shaped branches, 15–50 cm erect shoots, and 2–5 strobili, native from eastern Canada to the eastern and north-central USA, globally secure (G5).
Doodia
Doodia (rasp fern, hacksaw fern) is a genus of Blechnaceae ferns from Asia to Australasia and Hawaii, with scabrous fronds and linear sori; taxonomically merged into Blechnum by some treatments, retained by PPG I.
Doodia aspera
Doodia aspera (prickly rasp fern), Blechnum neohollandicum, a rough-fronded Blechnaceae fern from eastern Australia with pink new growth; probably extinct in New Zealand, 2n = 64.
Dryopteridaceae
Dryopteraceae, the wood fern family, is one of the largest terrestrial and epiphytic fern families, typified by Dryopteris, containing over 2,100 species and x=41 spores.
Dryopteris
Dryopteris (wood ferns, buckler ferns), genus Adanson 1763 in Dryopteridaceae, about 400 species, x=41, scaly rhizomes and reniform indusia; includes male fern D. filix-mas and absorbed genera Acrophorus, Diacalpe, Dryopsis, Nothoperanema, Peranema.
Dryopteris filix-mas
Dryopteris filix-mas, the male fern, a circumboreal deciduous wood fern (Dryopteridaceae) with 2-pinnate fronds to 1.2 m; allotetraploid from D. caucasica and D. oreades; RHS Award of Garden Merit; NatureServe G5.
Dryopteris marginalis
Dryopteris marginalis, marginal wood fern or marginal shield fern, is an evergreen Dryopteridaceae fern native from Greenland and Canada to the USA, growing in rocky, boulderfield temperate forests with sori along pinna margins.
Ecological roles of ferns
Ferns act as chemical-defended foliage for insects, facultative hosts of root fungi, nitrogen-fixing partners with Azolla in rice paddies, and microclimate engineers that enrich soils and shelter tree seedlings.
Ecology of filmy ferns
Ecology of filmy ferns (Hymenophyllaceae): over 600 hygrophilous, poikilohydric ferns with one-cell-thick leaves lacking cuticle and stomata; mostly epiphytic in humid tropical montane forests, richest in Central and South America and Southeast Asia.
Ecology of Marsileaceae
The ecology of Marsileaceae, water clovers and pillworts, is shaped by unreliable wetlands: sporocarps survive decades to a century dry, then germinate within hours of wetting.
Elaphoglossum
Elaphoglossum (tongue ferns), a Dryopteridaceae fern genus of 600 to 1,100 species with simple fronds and acrostichoid sori, mostly American tropical epiphytes, five molecular clades, Miocene amber fossil.
Epiphytic ecology of Polypodiaceae
The epiphytic ecology of Polypodiaceae, the polypody family of over 1,600 fern species, covers canopy strategies: foliar water uptake, desiccation tolerance, humus collecting, and ant mutualisms in tropical forests.
Epiphytic ferns
Epiphytic ferns are ferns that grow rooted on the surface of another plant, making up roughly 10% of vascular epiphyte species worldwide, mostly in tropical forests.
Equisetaceae
Equisetaceae, the horsetail family, is a spore-bearing vascular plant family whose sole living genus Equisetum has 15 species in three subgenera, a Carboniferous fossil record, and a cosmopolitan distribution.
Equisetales
Equisetales, the horsetail order of ferns (Polypodiopsida, Equisetidae), dates to the Devonian; only Equisetaceae and the genus Equisetum survive, with mid-Paleogene crown age and Triassic fossil relatives.
Equisetum
Equisetum (horsetails) is a spore-producing vascular plant found globally (except Antarctica), distinguished by hollow aerial stems and nodes. It is the sole living genus of Sphenopsida.
Equisetum arvense
Equisetum arvense, field or common horsetail (Equiseti herba), a spore-bearing perennial of Equisetaceae native to the temperate Northern Hemisphere, with silica-rich jointed sterile stems, spring fertile cones, EU herbal monograph use, and weed status.
Equisetum palustre
Equisetum palustre, the marsh horsetail (French prêle des marais), is a poisonous perennial horsetail of temperate Northern Hemisphere wetlands, toxic to livestock through thiaminase and alkaloids.
Eusporangiate and leptosporangiate sporangia compared
Eusporangiate and leptosporangiate sporangia are the two fern sporangium types: eusporangiate ones form from many cells and shed thousands of spores, leptosporangiate ones from a single cell.
Eusporangiate ferns
Eusporangiate ferns: ferns whose sporangia develop from multiple initial cells, covering Equisetales, Psilotales, Ophioglossales, and Marattiales; a non-monophyletic grouping contrasted with the single-initial, stalked sporangia of leptosporangiate ferns.
Eusporangium development
A eusporangium is a fern sporangium that develops from a group of cells rather than a single mother cell, with a several-layered wall, very large spore output, and no annulus.
Evolutionary history of Equisetum
The evolutionary history of Equisetum, the horsetails, shows striking morphological stasis: molecular clocks place the genus's origin in the Early Jurassic or earlier, making it the oldest living vascular plant genus.
Fern
Fern: vascular spore-producing plants (Polypodiopsida) with fronds, sori, and a two-stage alternation-of-generations life cycle; over 300 million years old, on every continent except Antarctica, distinct from fern allies like horsetails.
Fern allies
Fern allies is a traditional, informal grouping of spore-bearing vascular plants that are not ferns, covering whisk ferns, clubmosses, spikemosses, horsetails, and quillworts; now abandoned as polyphyletic.
Fern biogeography
Fern biogeography is the study of where ferns and lycophytes occur worldwide and how dispersal, climate, and history shape those patterns, with richness peaking in wet montane tropics.
Fern cultivation
Fern cultivation is the practice of growing ferns as ornamental garden or container plants; most are woodland subjects wanting shade, moisture-retentive well-drained soil, and little feeding.
Fern propagation
Fern propagation is the set of techniques for creating new ferns: sowing spores through a two-generation life cycle, or cloning by rhizome division, bulbils, and runners.
Fern rhizome
A fern rhizome is the fern's stem, usually creeping underground, bearing roots and fronds; in tree ferns it can form a trunk up to 20 m tall.
Fern spike
A fern spike is an abrupt, short-lived rise in fern spores in the fossil record, marking rapid recolonization of devastated land by ferns after a catastrophe.