While planning a group trip to the Carolinas and area for this spring, I've been revisiting some of my photographs from last year. This is a tentative identification for the subject fern in this image. If someone wants to assert that it is instead a species of Athyrium from the area (see A Natural History of Pearson's Falls and Some of Its Human Associations for a species list), I could be swayed. Unfortunately, the foreground stream along with considerations for the rental car (wet shoes) and the property (Pearson's Falls) precluded a closer look.

Dryopteris marginalis is endemic to eastern North America, extending southwest from the southern tip of Greenland to Kansas and Oklahoma. According to the Flora of North America for Dryopteris marginalis, it is a species of "Rocky, wooded slopes and ravines, edges of woods, stream banks and roadbanks, and rock walls". It appears to me that this plant is periodically submerged by the stream during periods of high waterflow.

The etymology of the specific epithet is explained by HardyFernLibrary.com (Dryopteris marginalis): "Marginalis means margined, referring to the position of the sori". A photograph illustrating the location of these spore-producing receptacles on the frond is also available on that site, or on the Ferns and Fern Allies of Wisconsin: Dryopteris marginalis.

From a series assembled and written by Alexis over the summer:

The prehistoric plant series continues today, and we progress through the geologic time scale to the Triassic period. Much thanks to Keith Board for sharing his photo of Osmunda claytoniana, which was taken in a swamp forest at the Indiana Dunes State Park in Porter County, Indiana. Keith is a contributor at this neat blog, Get Your Botany On!.

Osmunda is a genus of about six terrestrial fern species. Osmunda species grow in open, wet environments such as bogs, swamps, and lake edges. The genus has a wide distribution throughout the globe, though it is limited by climates that are too cold or dry (Tryon & Tryon's Ferns and Allied Plants (1982)).

Osmunda claytoniana has the "oldest known fossil record of any living fern", and can be traced back to the Triassic period. This species can also be considered a living fossil, because it appears almost identical to a fossil fern species from 200 million years ago, Osmunda claytoniites. It has gained the common name interrupted fern because of the appearance of its fronds, on which the brown fertile pinnae "interrupt" the green sterile pinnae.

Alexis continues with the prehistoric plant series she assembled in the summer:

Thank you to Forest & Kim Starr for sharing their photos from Maui, Hawaii via Wikimedia Commons (photo 1 | photo 2). Psilotum nudum grows in subtropical and tropical conditions and can be epiphytic.

Plants of the Psilotales, such as the pictured Psilotum nudum, are recognized as the most primitive plants currently living. Psilotum species are known as whisk ferns and though they do not appear in the fossil record, they share characteristics with extinct flora like Cooksonia.

The Rhynie Chert in Scotland is a sedimentary rock formation that contains a variety of fossilized plants and animals from the Early Devonian period, about 400-412 million years ago. It contains very well-preserved specimens of early vascular plants like Aglaophyton, which, like today's Psilotum, had no true leaves or roots, possessed rhizomes and sporangia, and a dichotomous branching pattern. Additionally, there is evidence that Aglaophyton species were myco-heterotrophic, having a symbiotic relationship with arbuscular mycorrhizal fungi that helped the plant to absorb nutrients; fungi often associate with present-day members of the Psilotales in the same way. Because of their similarities to Devonian flora, whisk ferns are uniquely significant for research purposes.

Alexis wrote today's entry:

The endemic Hawaiian plant series continues today with this photo from Forest and Kim Starr, via Wikimedia Commons. Thank you, Forest and Kim!

The genus Cibotium belongs to Dicksoniaceae, a family of tropical ferns with trunk-like stems that dates back to the Triassic, between 251 and 199.6 million years ago. There are four Cibotium species native to Hawaii; all are endemic to the islands and all are called Hawaiian tree ferns or hapu'u. Cibotium menziesii can be found growing in the ground or as an epiphyte in moist or wet forests on all the major Hawaiian Islands. This species is sometimes called the "male tree fern", while Cibotium glaucum is called the "female tree fern", although they are two different species. Cibotium menziesii is the largest tree fern of Hawaii, ranging from about 2 to 8 m in height but sometimes growing over 10m tall.

Hawaiian tree ferns are known and valued for their pulu, the soft wool that covers the bases of the stipes. Traditionally, Hawaiians used this material to embalm bodies and dress wounds. It was also exported to California for use as pillow and mattress stuffing (Hillebrand's Flora of the Hawaiian Islands (1888)). In addition, the starch-filled core of the plant is eaten by wild pigs and is considered a famine food for humans. More pleasing to the taste buds are the fiddleheads or furled fronds, which can be boiled and eaten.

A bona fide native of Japan is featured today, with the photograph courtesy of Eric in SF@Flickr: Cyrtomium caryotideum. Thanks once again!

Cyrtomium caryotideum has a number of common names: dwarf holly fern, dwarf netvein hollyfern, and fishtail holly fern, to name a few in English. Though fronds can reach approximately 70 cm, the "dwarf" part of the common names refers to how this species compares to others in its genus (Cyrtomium falcatum is about twice the height). Holly and fishtail are both allusions to how the pinnae resemble such things.

In today's photograph, dozens of sori, or clusters of spore-producing structures, are obvious beneath each pinna. Fern spores when homosporous (all spores are roughly the same size and type), as they are in Cyrtomium, can permit long-distance dispersal. Light and very easily airborne, the spores of Cyrtomium caryotideum have likely helped this species disperse across a wide range: not only is the species native to Japan, but also China, Bhutan, India, Nepal, Sri Lanka, Taiwan, Philippines and Hawaii (link contains many photographs of the species).

Today's photograph was taken on a January visit two years ago to the impressive Ferns Conservatory at the Montréal Botanical Garden, Canada's largest botanical garden. The scanned illustration (and the accompanying text in the first comment below) are from a public domain work by Sir William Jackson Hooker, Garden ferns; Or, Coloured figures and descriptions: with the needful analyses of the fructification and venation, of a selection of exotic ferns adapted for cultivation in the garden, hothouse, and conservatory. This book was digitized by Google and can be downloaded in its entirety as a PDF or viewed online.

Adiantum is broadly distributed worldwide, with centres of diversity in Andean South America and eastern Asia. Representatives of the genus are also found in North America (Adiantum aleuticum), Europe, Africa, Australia and New Zealand.

It is difficult to find much information online about this particular species. Native from Venezuela to Peru, Adiantum polyphyllum was scientifically described and published in 1810 by the German botanist Carl Willdenow. However, the specimens he described were likely collected by the "founder" of biogeography and plant explorer, Alexander von Humboldt. For an excellent overview on the topic of ferns and biogeography, see: Barrington, D. 1993. Ecological and Historical Factors in Fern Biogeography. Journal of Biogeography. 20(3): 275-27. (might be a restricted-access link).

Known commonly, perhaps, as either giant maidenhair or many-leaved adiantum, Adiantum polyphyllum is a sizable fern (see this photograph), with a stipe to perhaps 0.6m (2ft) in height and fronds reaching an additional 1m (3ft) in length. I was struck, as Hooker describes it, by the "intensely ebeneous-black stipites and rachises".

Asplenium scolopendrium or hart's tongue fern is an evergeen limestone-loving plant. Two varieties of the genus exist. They are nearly impossible to distinguish by form—the clearest distinction is that the American variety is tetraploid and var. scolopendium is diploid. Variety scolopendrium is found primarily in Europe, but is also found in parts of Asia and northern Africa. Variety americana is rare and found in isolated populations in North America. Some botanists place one of these populations, found in Mexico, into a third variety—lindenii. Our plants and virtually any found in cultivation are of var. scolopendrium—var. americanum performs poorly in cultivation—it barely survives in the wild. Plants are quite variable and the species hybridizes with other Aspleniums. Several forms have been selected for ornamental use.

Asplenium scolopendrium spreads by rhizomes to form drifts in shady areas, growing slowly, but needing little attention from the gardener. The erect leaves are 10-60 cm long and 3-6 cm wide—in extreme cases they may grow to 90 cm by 10 cm. The two rows of lines of sori arranged along the rachis of the leaf were thought to resemble a centipede. The species takes its name from this appearance—scolopendra is Greek for centipede.

Eric La Fountaine wrote and posted today's photographs and entry.

The bird's nest fern is a tropical species native to southeast Asia, Japan, Taiwan, Australia, eastern Africa, and Polynesia, including Hawaii, where this photo was taken. It can be found growing in soil or as an epiphyte on trees. The fronds can grow to 150 cm long and 20 wide. It is easily grown indoors and is a common house plant. Typically a very bright green, the colouration of the plant in these photos is that of winter, as the photo was taken in late December.

For further reading on ferns, take a look at A Brief Introduction to Ferns from the American Fern Society.

This entry was schedule to appear yesterday. Unfortunately an unknown problem arose and it did not appear as scheduled. My apologies.

Today's entry was written by Randal Mindell, a botanist working on a special project at UBCBG. Randal took the close-up photo and I took the full view. Randal writes:

Fronds of Osmundastrum cinnamomeum (cinnamon fern) come in two forms: tripinnate vegetative fronds and tripinnate reproductive fronds. This differs from the coupling of reproductive structures on vegetative, photosynthetic leaves common to the vast majority of filicalean ferns. The distinction between the two frond types is easy to see in the picture, with tan fertile material encircled by traditional, verdant foliage. If you feel like you have seen this before, perhaps you are thinking of other erect and iconic ferns such as Blechnum spicant (deer fern), Onoclea sensibilis (sensitive fern) or Matteuccia struthiopteris (ostrich fern).

Among living ferns, the family Osmundaceae has one of the longest fossil records. It traces back to the Paleozoic, and is widely distributed across the northern hemisphere during the Mesozoic. Given the widespread nature of Osmunda cinnamomea in the present (North & South America, Asia), I would like to reflect on the reproductive potential that fuels its dispersal. Plants here at the garden give off anywhere from 5-10 fertile fronds. An informal count revealed that these fronds produce anywhere between 11-19 pairs of primary pinnae (primary divisions of the leaf), which in turn give off anywhere between 13-20 pairs of secondary pinnae. Counting the tertiary pinnae (the sterile tissue on to which the sporangia are borne) is too painful, but a count of sporangia on a few secondary pinnae averaged 45 per pinna. Putting these loose numbers together (fertile fronds × primary pinnae × secondary pinnae × sporangia per secondary pinna) and multiplying them by the 64 spores per sporangium that is standard for the Dryopteridaceae, we see that one individual has the potential to produce anywhere from 8-43 million photosynthetic spores.

I'm on vacation, so please accept my apologies for the brief entries. -- Daniel.

Thank you to Weekend Gardener@UBC Botanical Garden Forums for contributing today's photograph via this thread on the Botany Photo of the Day Submissions Forum. It's very much appreciated, once again.

This species underwent a name change in 2003 from Leuzea conifera to the now-accepted Rhaphonticum coniferum. It is native to southwestern Europe and northwestern Africa. The reason for the epithet, coniferum, should be obvious with this photograph -- the involucre's resemblance to a coniferous cone is unmistakable. It reminds me of another member of the aster family: Centaurea macrocephala.

Thank you to Jackie Chambers, UBC Botanical Garden Horticulturist, for both today's photograph and write-up!

Close inspection of this photo reveals what appears to be the remains of a fern nestled in the rock crevice -- there are no obvious signs of life, no green photosynthetic surface is visible, and the leaves are curled inward revealing the rusty coloured trichomes or hairs that line the undersides. At first glance, the fern in this photo may appear somewhat uninspiring; however, Asplenium ceterach (syn. Ceterach officinarum) is a fascinating little plant.

A fern with a preference for dry places, the rustyback fern has an amazing drought tolerance. The vegetative organs of the plants can dry out completely when moisture is lacking, and then revive without injury when water becomes available. When not in its desiccated state, the fern has shiny green fronds that range from 3-20cm long, depending on environment. The leaves are pinnate and leathery, with the rusty-brown hairs hidden on the undersides. It also has a short rhizome, which serves to secure the plant to cracks in walls or rocky surfaces. The Skye Flora's page on Asplenium ceterach gives an excellent idea of what the plant looks like when fully hydrated.

Asplenium ceterach has a native range that extends across parts of Europe, northern Africa, and into temperate Asia. This means it can be found in a range of countries and locations: from dry stone walls in parts of the UK to the hot, rocky outcrops along the coast of southern Spain like the one above.

Ferns differ from angiosperms or flowering plants in that they do not rely on flowers or seeds for reproduction -- part of their life cycle includes a sporophyte (spore-producing entities) phase and a portion of their life cycle include as gametophyte phase (or gamete-producing organism). This is called alteration of generations, and is described more fully in Wikipedia's section on ferns.

The interesting lives of spore-bearing plants are celebrated in verse on this website, Cryptogams: Poems, where the author has dedicated a poem to the resurrection abilities of Asplenium ceterach (listed under a synonym, Ceterach officinarum).

Thank you again to Krystyna Szulecka for sharing another of her excellent photographs (posted in this thread in the BPotD submissions forum). If you like, see more of Krystyna's images by searching for “Krystyna” on the FLPA web site.

Given its distribution, it's doubtless that Dicranopteris linearis has dozens of common names. Four names frequently used are Uluhe fern, climbing fern, false staghorn and Old World forked fern. According to GRIN, it can be found in tropical and subtropical areas throughout the Old World. That left me puzzled for a bit, as Plants of Hawaii Volcanoes National Park lists it as indigenous and the USDA PLANTS database displays it as native to Hawaii The mystery was partially resolved when I looked at GRIN's entry for Dicranopteris linearis f. marginata, noted to be found in Hawaii. So, it appears to be a small oversight that Hawaii isn't included in the broader distribution list.

The Plants of Hawaii Volcanoes National Park has a photograph clearly illustrating the reason for one of the common names, climbing fern. More photographs, particularly with respect to propagation, are available in the PDF suggested by Krystyna: The Propagation and Production of Uluhe Fern (Dicranopteris linearis) for Potential Use as a Restoration Species (a presentation given to the International Plant Propagators' Society).

The New South Wales Flora Online provides a small scientific description of the species.

First-time contributor Dana Cromie (a UBC BG Friend of the Garden) has shared today's image from a visit to Hawaii (original | BPotD Flickr Group Pool). Thank you, Dana!

I've decided to post the photograph from what I believe to be accurate orientation as well as the flip; a visit to the image on Flickr will also show it in a horizontal perspective. The strong lines of the image gave me a few minutes of enjoyment as I examined the photo in different orientations, so that was my reason for posting it like this.

Commonly known as amau or ‘ama‘u in Hawaiian (and sometimes known as rasp fern), Sadleria cyatheoides is an endemic to the archipelago. It is a plant of wet habitats that can be found from near sea-level to 2135m (7000 ft.). For a small factsheet about the plant, visit Plants of Hawaii Volcanoes National Park. Many more photographs are available from the Plants of Hawaii site, Sadleria cyatheoides.

Thank you to Stephen B of Scotland aka stephenbuchan@Flickr for another couple photographs shared with BPotD (original 1 | original 2 | BPotD Flickr Pool). As always, it is very much appreciated, Stephen.

Bracken fern can be found throughout most of the world. The advantage of featuring one of the most widely distributed vascular plants is that there is a wealth of information online.

On its classification: Is it one species with many subordinate taxa (i.e., subspecies and varieties)? Or is there now enough evidence to break up the one species into ten or so distinct species? The Flora of North America's entry on Pteridium aquilinum notes the “disagreement existing among taxonomists” with a summary of evidence pointing to splitting up the one species into multiples, but still opts for a single-species approach. This illustration from the Flora of North America shows the variability of form between taxa.

On edibility: The Plants for a Future database, as always, details the edibility and other economic uses, but accompanies it with a warning about potential health risks of ingestion. The Nova Scotia Museum simply labels it carcinogenic, with the suggestion that it is to be avoided. Wikipedia summarizes how bracken is used (and eaten) by several cultures.

Peeking at the undersides of licorice fern fronds at this time of year often rewards you with a display of their orange, naked sori. The sori are clusters of sporangia, or spore-containing structures (see this illustration of the fern life cycle). The term naked is used because the sori lack a protective covering called the indusium; for comparison, here's a photograph of sori (partially) covered by indusia on Polystichum.

The epithet glycyrrhiza means sweet root and refers to the genus Glycyrrhiza, a member of the bean family. The root of Glycyrrhiza is better known as licorice (or liquorice). The rhizomes and stems of Polypodium glycyrrhiza are similarly flavoured, hence the common name of licorice fern.

Polypodium glycyrrhiza is distributed along the coastal regions of western North America, as well as the Kamchatka region of Asia. The Hardy Fern Library provides a detailed description of licorice fern.