Time-lapse recording of the dehydration motion of a single, detached mature false indusia. S4 Video. Time-lapse recording of the adaxial surface of a false indusium during dehydration. S5 Video. Slow passive nastic annulus movement and fast relaxation entailing spore ejection. S6 Video. Annulus relaxation and spore ejection, recorded with S7 Video. S8 Video. Annulus relaxation and spore ejection recorded with S9 Video.
S10 Video. S11 Video. Annulus relaxation, spore ejection, and spore scattering recorded with S12 Video. Slow return of the annulus towards its almost initial configuration after relaxation. S13 Video. Time-lapse recording of the dehydration motion of a mature false indusium.
Acknowledgments The authors gratefully acknowledge the help of Heidi Petarus, Tillmann Lohff and Joachim Ehlers from the Botanic Garden Freiburg and thank the reviewers for their helpful comments and suggestions. Author Contributions Conceived and designed the experiments: SP. References 1. Phylogeny and evolution of ferns monilophytes with a focus on the early leptosporangiate divergences.
Am J Bot. Pryer KM, Schuettpelz E. Ferns Monilophyta. The timetree of life. New York: Oxford University Press; Influences of life history attributes on formation of local and distant fern populations.
Am Fern J. View Article Google Scholar 4. Schneller JJ. Aspects of spore release of Asplenium ruta-muraria with reference to some other woodland ferns: Athyrium filix-femina , Dryopteris filix-mas , and Polystichum aculeatum. Bot Helv. View Article Google Scholar 5. A classification for extant ferns.
Taxon ; — View Article Google Scholar 6. The contributions of population studies on ferns. View Article Google Scholar 7. Tryon R. Development and evolution of fern floras of oceanic islands. Biotropica ;2: 76— View Article Google Scholar 8. Page CN. Ecological strategies in fern evolution: a neopteridological overview.
Rev Palaeobot Palynol. View Article Google Scholar 9. Kessler M. Biogeography of ferns. Fern ecology. Cambridge: University Press; Klotzsch JF.
Linnaea ; — View Article Google Scholar The ecology of Peruvian ferns. A report on pharmacognostical evaluation of four Adiantum species, Pteridophyta, for their authentication and quality control.
Rev Bras Farmacogn. Quantitative studies of pinnule development in the ferns Adiantum raddianum and Cheilanthes viridis. A morphological assessment of Adiantum hispidulum Swartz and A. New Zeal J Bot. Spore maturation and release of two evergreen Macaronesian ferns, Culcita macrocarpa and Woodwardia radicans , along an altitudinal gradient. J Syst Evol. Is morphology really at odds with molecules in estimating fern phylogeny?
Syst Bot. Simpson MG. Plant systematics. Oxford: Elsevier; Indehiscent sporangia enable the accumulation of local fern diversity at the Qinghai-Tibetan Plateau. BMC Evol Biol. Lyon FM. Dehiscence of the sporangium of Adiantum pedatum. Bull Torrey Bot Club. Atkinson GF. The study of the biology of ferns by the collodion method: for advanced and collegiate students.
New York: Macmillan and Co; Steinbrinck C. Der Oeffnungs- und Schleudermechanismus des Farnsporangiums. Ber Dtsch bot Ges. Ursprung A. King AL. The spore discharge mechanisms of common ferns. PNAS ; — Haider K. Zur Morphologie und Physiologie der Sporangien leptosporangiater Farne. Planta ; — Straka H.
In: Ruhland W, editor. Berlin: Springer Verlag; Ingold CT. Spore liberation. Oxford: Clarendon Press; Xylem Structure and the ascent of sap. New York: Springer; Biomechanics of fern spores discharge: the sporangium opening. In: Thibaut B, editor. Proceedings of the 6th Plant Biomechanics Conference. Cayenne: Ecofog; The acoustic detection of cavitation in fern sporangia. J Exp Bot. The fern sporangium: A unique catapult. Science ; Fiji: an open-source platform for biological-image analysis.
Nat Methods ;9: — Active discharge distance of ascospores of Venturia inaequalis. Phytopathology ; — Meiotic studies in the genus Adiantum. Caryologia ; — Tree fern indusia: studies of development and diversity.
Can J Bot. Skotheim JM, Mahadevan L. Physical limits and design principles for plant and fungal movements. Science ; — Elbaum R, Abraham Y. Insights into the microstructures of hygroscopic movement in plant seed dispersal. Plant Sci. Hydro-actuated plant devices. Nonlinear elasticity and hysteresis: Fluid-solid coupling in porous media. KGaA; Bianchini M, Pacini E. Explosive anther dehiscence in Ricinus communis L. Int J Plant Sci. How the Venus flytrap snaps.
Nature ; — Faster than their prey: New insights into the rapid movements of active carnivorous plants traps. Bioessays ; — Mechanics without muscle: biomechanical inspiration from the plant world. Integr Comp Biol. Aspects of spore dispersal in Selaginella. Buller AHR. Researches on fungi. London: Longmans; Gregory PH. The dispersion of air-borne spores. T Brit Mycol Soc. A differential thickening of the cell walls causes the curved annulus to straighten, thus ripping apart the thin-walled lip cells and releasing the spores.
Germination of a spore produces a minute heart-shaped prothallus gametophyte. The birth of a fern: A tiny fern sporophyte S emerging from a transparent, thalluslike fern gametophyte G. Small rootlike rhizoids can be seen on the lower side of the gametophyte. Fern spores germinate and grow into a transparent gametophyte before the typical fern sporophyte appears.
This is how all ferns start, including the first fern spores that ever reached the Hawaiian Islands by strong winds and air currents, long before the arrival of the first Polynesian sailors. The head of an ordinary straight pin is shown as a size relation. Signs have been placed in Palomar Mountain State Park to discourage the picking of young, uncurling fronds called fiddleheads. Right: Closeup view of immature, uncurling frond called a fiddlehead or crosier. In Asian countries, fern fiddleheads of a related species are steamed and eaten with rice as a side dish or mixed with other vegetables.
Fresh fiddleheads have a pleasant buttery, nutty flavor. Considering that each fiddlehead develops into a large compound leaf, numerous people foraging for fern fiddleheads on Palomar Mountain could decimate the population of this lovely fern. Australian tree fern Alsophila australis showing the uncurling frond called a fiddlehead or crosier.
Smaller divisions of the compound leaf called pinnae also uncurl as the large leaf expands. Mother Fern Asplenium bulbiferum , an interesting Australian fern that produces miniature plantlets or bulblets on its leaves. The red arrow points to the tiny fiddlehead of a plantlet.
Sometimes the term viviparous is used for plants that bear live young. A petrified trunk from the extinct tree fern Psaronius brasiliensis. The central stele region contains arc-shaped vascular bundles of xylem tissue. The stem is surrounded by leaf bases which formed the leaf crown of this fern, similar to present-day Cyathea tree ferns of New Zealand.
This petrified stem has been cut and polished to make a pair of bookends. A well-preserved stem section from the extinct tree fern Psaronius brasiliensis. Note the central stele region containing arcs of xylem tissue vascular bundles.
The structure of this stem is quite different from the concentric growth rings of conifers and dicots, and from the scattered vascular bundles of palms. Clover-leaf Fern Marsilea vestita , showing the characteristic compound leaves divided into 4 leaflets. Pillworts Pillularia americana , an interesting member of the division Pterophyta Order Marsileales in vernal pool areas of southern California. The simple, filiform leaves are usually less than 6 cm long. The small, pill-like structures are sporocarps that contain male microsporangia and female megasporangia.
The generic name is derived from the Latin pilula little ball , referring to the globose shape of the sporocarp. Like the quillworts Isoetes , this plant is often overlooked because of its small, grass-like appearance. Two adder's tongue ferns Ophioglossum californicum , an interesting and uncommon member of the division Pterophyta Order Ophioglossales. Each fern has a basal leaf and upright reproductive stalk.
Probably the most difficult feature of the zygomycotan sporangium for most students to understand is the bulb-like structure called a columella. The columella is simply the end of the sporangiophore, enlarged so that it extends up into the sporangium. The picture of Rhizopus domesticus at near-left shows these relationships fairly well. The columella can be seen as a spherical body inside the large spherical sporangium. If you examine the photo carefully you will see where the columella connects to the sporangiophore on the right side.
The spores inside the sporangium surround the columella but are never inside it. The photo at far-left shows a sporangiophore of Absidia spinosa. Here the sporangium has ruptured and released all of its spores. What is left is the sporangiophore topped by a columella, with the remnants of the sporangial wall remaining as a cup. The columella of Absidia spinosa , and that of some other Zygomycota as well, is characterized by the presence of an apophysis , a small pointed extension on its upper surface.
It is these "naked" columellae, free of the sporangium and spores, that cause beginners so much confusion.
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