Friday fabulous fern - for real

A small track off the highway is all there is at the Kaimai Summit track.  This little loop to the summit on the North Island is one of the ferniest places TPP has ever been.  Filmy ferns are everywhere, and over all TPP saw nearly 3 dozen species of ferns, although he could not identify more than a handful.  Here's a nice whorl of new fronds, and this if probably a Blechnum discolor, but that may take some confirmation.  Generally this fern is called a dwarf tree fern although it really doesn't get very tall.

The forest floor was spongy with litter and it was quite damp as might be expected where filmy ferns abound.  

Millions of ferns

The Phactors are attending Botany2017 in Ft. Worth TX.  Among the many things learned already was Casa Flora (actually SE of Dallas) is one of the largest wholesale producers of ferns in the world.  They propagate around 150 different species of ferns using either tissue culture or spore culture.  Both are quite impressive operations resulting in vast numbers of ferns - acres of ferns.  If you buy a decent sized fern in the USA, chances are it started it's life here.  Here's a room (only partly shown) of trays, under artificial light where trays of spores are grown, in remarkable numbers, so the trays are filled with very young plants, and then they are transplanted into trays of 72 plants and further grown in a greenhouse area, one of many.  The images show the trays, the young ferns in the trays (photo taken through the saran wrap) and then the flats of small ferns filling a large greenhouse.  Even the catalog, available at the link above is impressive.

Fiddlehead crown

Our gardens can generally be classified as shady, so TPP has been working at increasing our fern diversity while keeping the ostrich ferns and sensitive ferns in check. Winter hardiness is not so much a problem as is the hot, dry summers of the upper midwest and the clay content of our soils. In addition to the usual garden ferns, a couple of more unusual ferns have managed to hang on even if not particularly flourishing.  Here's a Hart's Tongue fern (Asplenium scolopendium) sending up it's spring fiddleheads. As you can readily see, the fronds are long, un-divided, straps, and often persist through the winter.  Given the rather tricky conditions needed for its culture, it's a bit of a surprise that this fern has survived under a Japanese maple although it has remained a fairly small plant and is kept caged to prevent it from becoming bunny candy and much smaller. Since it is native in Michigan and New York, it's no surprise it doesn't like our summers. Our local fern growing guru says it's doing well. His fern and moss garden/collection is impressive, but requires watering and quite a bit of care.  And he's just offered us some new plants. Nice!

Growing some haploid ferns

Today's task is to have students start growing some haploid ferns.  Your familiar ferns are diploids and they are asexual producing spores.  Novices often think they have spores but really they have sporangia, which have 128, 256, or 512 spores, there abouts, in them.  They are looking for something small, but they don't realize how small.  If you want to do this yourselves, here's how.  Find a fern with mature sporangia.  The sori, clusters of sporangia, usually look brown at this stage. Take two pieces of white paper.  Fold one into corners and crease it, then flatten the paper back out.  Place the fern frond on the paper sporangia side down.  Cover with the other piece of paper and leave it over night.  As the specimen dries out, the spores are shed onto the paper; look for brownish dust.  The creases make it easy to gather the spores by tapping the paper.  Go to a local garden store and buy a Jiffy 7; they cost about 15 cents.  It's a little compressed pellet of peaty soil in a little mesh bag.  Soak it in water overnight and it will expand.  Get a wide mouth pint canning jar, or an empty peanut butter jar, or something similar.  Turn it upside down and place the Jiffy 7, now more like a Jiffy 42 on the lid to produce a growth chamber terrarium.  Tap spores sparsely onto the surface of the Jiffy 7.  Cover with the jar, screw into the lid and place in a north window.  You don't want direct sunlight, so you also could place it back a ways from a brighter window.  A couple of weeks later you should see green growth.  It's OK to take them out to examine them, and should they need a bit of water place the Jiffy 7 in some shallow water for a few minutes, then return it to its growth chamber.  In 2 months you should have flat haploid ferns about the size of your little finger nail; they are actually called a gametophyte thallus, but it's still a fern, just haploid.  This is the sexual stage of the fern.  A mist of water will cause mature antheridia to release sperm and should a mature egg be around, fertilization will occur and a bit later you'll see the first frond of a diploid fern appear (the familiar phase).  With some patience this can will grow to maturity. 

Going Gaga over a fern

Honorifics are either generic or specific epithets that honor someone by using their name.  They are quite common actually, and sometimes they can be humorous or down right mean.  Consider Ruiz and Pavon who named the genus Galinsoga after a Dutch rival saying that the beauty and size of the flower matched his botanical accomplishments, except the flowers were small and not very attractive.  So this is pretty funny actually, a new fern genus, Gaga, yes, an honorific for Lady Gaga, and it was done by one of my good colleagues, Kathleen Pryor, in the most recent issue of Systematic Botany.  Now they could have done better with the title of the article, “Going Gaga over ferns” or something like that, but it’s still pretty catchy.  The resemblance is pretty obvious in this illustration except they are comparing this haploid fern to the diploid singer.  HT to AoB blog and No seeds, no fruits, no flowers; no problem blog. 

Horsetails are not ferns!

Common names cause a lot of grief, but they remain friendly, although often uninformative or misleading, easy to remember, and at times they are useful as shorthand references.  They certainly have their place in teaching and outreach.  Now here's the particular problem.  Molecular data nests the horsetails within the lineage of what traditionally have been called ferns.  OK, fair enough, but that does not make horsetails into ferns.  In a classification of extant (living) ferns published in 2006 my colleagues label the whole lineage "ferns".  Right now the Phactor does not wish to argue about whisk ferns (also called psilophytes) in this same context.  But horsetails have been  distinct from ferns back to the point when there were neither ferns nor horsetails, but merely a group of plants that were the likely common ancestors of ferns and horsetails, and even within this group their respective ancestors were different.  Traditionally, the lower vascular plants (those without seeds) were called the pteridophytes - the fern-like plants.  Now this is fine and everyone understood what was meant, but the beautiful people have decided that because pteridophytes used to include the clubmosses, the term must be avoided.  True, the clubmosses are a separate lineage, so you must re-define pteridophyte to exclude the clubmosses, and this type of thing is done all the time.  Pteridophyte always had a broader connotation than the term "fern"; it basically meant the "ferns and fern allies (which also included clubmosses)".  When you say fern, the image your mind forms is not at all what you see when someone says "horsetail".  Until people get used to the narrower definition of pteridophyte there will be some confusion, but certainly that produces no greater confusion than calling horsetails "ferns".  Part of the trouble is that the plants traditionally considered "ferns" do not form a single lineage; no lineage of ferns exists unless you include the whisk ferns and horsetails, but now you've got pteridophytes.  So the Phactor still sees considerable utility to pteridophyte to label the whole lineage, although now redefined to exclude clubmosses, because he cannot bring himself to call a horsetail a fern. If anyone wants this publication, go to this link (Kathleen Pryer's web page), scroll down to 2006; it's the 1st entry.  What think you RE ferns and horsetails?

Branching out - tree architecture

Plants truly became trees when two innovations coincided: woodiness and axillary branching, a continuation of growth from buds that arise in the angle between leaves and stems, leaves being modified lateral branches anyways. Before axillary branching, branching took place only at the apex, and this very much restricts the forms that can result, but axillary branching allows new modules, iterative growth, and this and only this produces a true trees, although clubmosses and ferns produce, or did produce, a type of arborescent growth. Hmm, this is very hard to explain without a lot of diagrams, a lot of fossils, and quite a bit of knowledge of plant anatomy. But sometime in the late Devonian, true trees appeared, and they appeared before seeds!
Here's another way to think about it. If you cut the top out of a coleus, all the axillary buds begin growing and the plant bushes out as all the new modules grow and develop, with the modules producing new modules. But if you cut the top out of a tree fern, or a cycad, or some conifers, well, that's basically it. It cannot produce new modules because there are not lateral buds to produce new modules, no interative growth. Sorry, too tired to figure this out any better. But it was a good talk, although quite technical.

Chlorofilms - Contest and Previous Winners

Chlorofilms sounds like some kind of green cellophane, but actually is an annual contest for videos about some aspect of plant biology; some are animated, some are documentaries, some are time-lapse, all are pretty creative. Among my favorites, although by no means the most sophisticated, are several films featuring Deedra McClearn, Director of La Selva Biological Station in northeastern Costs Rica, a facility run by the Organization for Tropical Studies. The Phactor conducts research there when time and money (and Mrs. Phactor) allow, and this is also where my rain forest ecology class goes for its annual field trip. These little videos focus on the fern flora from the surrounding rain forest and there's are lots of pterrific little bits included. Perhaps someone out there will get inspired to enter this year's contest.

A real resurrection (fern)

Is there a plant grower anywhere who has never accidentally let a plant dry out and die? Doh! Dehydration is such an annoyance. Yet there are a number of organisms that can dry out and survive quite well. Slime molds and yeasts can be dehydrated and survive for months. Some mosses and leafy liverworts can dehydrate, and rehydrate, on a daily basis, and sometimes for even longer periods of time. But when you get to vascular plants the ability to survive dehydration becomes rare perhaps because the whole idea of vascular tissue, cuticle, and stomata is to maintain a hydrated state, as long as the roots can replace the water being continually lost through transpiration. Of course comparing vascular plants to mosses and liverworts is not fair because the former are diploids and the latter haploids (explanatory link). But the point is that among vascular plants the ability to dehydrate and survive is rare, and no matter what, no one really seems to understand how even a slime mold can dehydrate into a brittle piece of yellow cytoplasm and then blob itself back to life when water is added.
One exception among vascular plants is the resurrection fern, Polypodium polypodioides. Sometimes they are sold as novelty items; just add water and the brittle fern rehydrates and greens up (see image). Cool. A recent report suggests that this ability is linked to appropriately named proteins called dehydrins, which appear to prevent cell wall damage from the “wrinkling up” that occurs when cells dry out. Could such a gene be used to engineer drought resistant crops? Maybe. And this is another example of why the powers that be, and that includes all of the people holding the purse strings, should encourage, rather than discourage, biologists to study a diversity of organisms. You can just imagine the derision a grant proposal would get from the USDA if you said you were going to study a cute little fern. Sure kid, how nice, now if you want money from us study corn, which never, ever suffers from droughts.

Ever seen a fern this pretty?

Here's a pretty image of a fern. Have you ever seen a fern like this one? No question about it, this fern is pretty small, about the same size as a neatly trimmed nail on your little finger, and at that size, a fern can be over looked pretty easily.

You may think that this fern doesn't look very fern-like, but in this you are wrong. Your experience with ferns is just too limited. Granted this fern has no ferny fronds, and no vascular tissue either, but I assure you it is quite typical. The most interesting thing about this fern is that it is haploid. The nucleus in each of its cells has only a single set of chromosomes. All of the ferns with which you are familiar have two sets of chromosomes. And what a difference this makes.

This haploid fern is the sexual phase of its life cycle. It makes sex cells, eggs and sperm, and after fertilization, it nutures, for a short while, an embryonic fern, which can grow into a typical appearing fern. So this haploid fern is not some strange, exotic beast, but just the alternate phase of the fern life cycle, the gametophyte phase, the gamete (sex cell) producing plant. Like all other vascular land plants, the familiar fern is the diploid phase, the sporophyte phase, the spore producing plant. And with that I am off to sow some spores and raise some haploid ferns.