Pinnation is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in patterns of erosion or stream beds.
Dryopteris expansa, the alpine buckler fern, northern buckler-fern or spreading wood fern, is a species of fern native to cool temperate and subarctic regions of the Northern Hemisphere, south at high altitudes in mountains to Spain and Greece in southern Europe, to Japan in eastern Asia, and to central California in North America. The species was first described from Germany. It prefers cool, moist mixed or evergreen forests and rock crevices on alpine slopes, often growing on rotting logs and tree stumps and rocky slopes. It is characteristically riparian in nature, and is especially associated with stream banks.
Dryopteris filix-mas, the male fern, is a common fern of the temperate Northern Hemisphere, native to much of Europe, Asia, and North America. It favours damp shaded areas in the understory of woodlands, but also shady places on hedge-banks, rocks, and screes. It is much less abundant in North America than in Europe. The plant is sometimes referred to in ancient literature as worm fern.
Gymnocarpium dryopteris is a deciduous fern of the family Cystopteridaceae. It is widespread across much of North America and Eurasia. It has been found in Canada, the United States, Greenland, China, Japan, Korea, Russia, and most of Europe.
Osmunda regalis, or royal fern, is a species of deciduous fern, native to Europe, Africa and Asia, growing in woodland bogs and on the banks of streams. The species is sometimes known as flowering fern due to the appearance of its fertile fronds.
Polystichum aculeatum, the hard shield-fern, is an evergreen fern native to Europe. It is most abundant in upland regions of the British Isles and western France, where it benefits from the combination of mild winters and moist summers, but also occurs more locally across most of Europe except northern Scandinavia, northern Russia; in the Mediterranean region it is confined to high altitudes. It grows on steep slopes in woodlands.
Polystichum setiferum, the soft shield fern, is an evergreen or semi-evergreen fern native to southern and western Europe. They remain lush and fresh-looking throughout the season. The stalks and most midribs are coated with attractive cinnamon-brown scales. The Latin specific epithet setiferum means “with bristles”.
Dryopteris erythrosora, the autumn fern, Japanese wood fern, or copper shield fern, is a species of fern in the family Dryopteridaceae, native to east Asia from China and Japan south to the Philippines, growing in light woodland shade on low mountains or hills.
Polystichum acrostichoides, commonly denominated Christmas fern, is a perennial, evergreen fern native to eastern North America, from Nova Scotia west to Minnesota and south to Florida and eastern Texas. It is one of the most common ferns in eastern North America, being found in moist and shady habitats in woodlands, stream banks and rocky slopes. The common name derives from the evergreen fronds, which are often still green at Christmas.
Dryopteris carthusiana is a species of fern native to damp forests throughout the Holarctic Kingdom. It is known as the narrow buckler-fern in the United Kingdom, and as the spinulose woodfern in North America.
Asplenium trichomanes is a small fern in the spleenwort genus Asplenium. It is a widespread and common species, occurring almost worldwide in a variety of rocky habitats. It is a variable fern with several subspecies.
Asplenium bradleyi, commonly known as Bradley's spleenwort or cliff spleenwort, is a rare epipetric fern of east-central North America. Named after Professor Frank Howe Bradley, who first collected it in Tennessee, it may be found infrequently throughout much of the Appalachian Mountains, the Ozarks, and the Ouachita Mountains, growing in small crevices on exposed sandstone cliffs. The species originated as a hybrid between mountain spleenwort and ebony spleenwort ; A. bradleyi originated when that sterile diploid hybrid underwent chromosome doubling to become a fertile tetraploid, a phenomenon known as allopolyploidy. Studies indicate that the present population of Bradley's spleenwort arose from several independent doublings of sterile diploid hybrids. A. bradleyi can also form sterile hybrids with several other spleenworts.
Fern sports are plants that show marked change from the normal type or parent stock as a result of mutation. The term Morphotype is also used for any of a group of different types of individuals of the same species in a population. Fern fronds in sports are typically altered in several ways, such as the frond apex divided and pinnae similarly duplicated.
Adiantum viridimontanum, commonly known as Green Mountain maidenhair fern, is a rare fern found only in outcrops of serpentine rock in New England and Eastern Canada. The leaf blade is cut into finger-like segments, themselves once-divided, which are borne on the outer side of a curved, dark, glossy rachis. These finger-like segments are not individual leaves, but parts of a single compound leaf. The "fingers" may be drooping or erect, depending on whether the individual fern grows in shade or sunlight. Spores are borne under false indusia at the edge of the subdivisions of the leaf, a characteristic unique to the genus Adiantum.
Dryopteris macropholis is a species of fern. It is distributed on the Marquesas Islands.
Gleichenia alpina, commonly known as alpine coral-fern, is a small fern species that occurs in Tasmania and New Zealand. It grows in alpine and subalpine areas with moist soils and is a part of the Gleichrniaceae family.
Cyathea borbonica is a tree fern endemic to Mauritius, Réunion and the islands of the south-western Indian Ocean. There are several natural forms and varieties.
Dryopteris dilatata, the broad buckler-fern, is a robust species of deciduous or semievergreen fern in the family Dryopteridaceae, native to Europe, particularly western and central Europe. In southern Europe, it is mostly found in mountainous regions. It is also found between the Black Sea and the Caspian Sea. It grows to 90 cm (35 in) tall by 120 cm (47 in) wide, with dark green tripinnate fronds, the ribs covered in brown scales.
Dryopteris inaequalis is an Afrotropical fern species that ranges from tropical and southern Africa to Madagascar. It has been recorded in Tanzania, Zambia, Malawi, Mozambique, Zimbabwe and South Africa, where it is present in the Western Cape, Eastern Cape and KwaZulu-Natal. It is found on forest floors and along forest margins, from middle to high altitudes.
Dryopteris aemula, the hay-scented buckler-fern or hay-scented fern, is a species of perennial leptosporangiate fern.
