Sunday, February 27, 2011

Osmunda regalis, a cosmopolitan with the feet in the water

Its primitiveness is perhaps the feature that best defines and because of its survival over millions of years. Not only has he been able to get to this day almost unchanged, but has been so successful that today is one of the most cosmopolitan ferns of the Earth, it dwells in every continent temperate, subtropical and tropical regions, except Australia and New Zealand. It is found throughout Europe, the Americas (North, Central and South America), in Asia, Africa, Madagascar and the Mascarene Islands, located in the southwest Indian Ocean. 

Fronds of an old Osmunda regalis with nearly two feet long in the bed of the Arroyo del Parron in the Natural Park of Los Alcornocales in the province of Cadiz in mid-May. (Double click on the photo to enlarge)

The origin of its name is very confusing, there are many theories, but most accepted the result makes the generic name of King Osmund, who reigned in Lower Saxony to the year 758 ac. The species name "regalis" (roial) would thus have the same origin and translates as: "Fern of King Osmund." Produces heteromorphic fronds: sterile and fertile. Its spores are a unique feature among the ferns, are green chlorophyll content, which facilitates germination.

The family Osmundaceae is an isolated group unrelated to other ferns. They have found fossils of primitive osmundaceae Permian strata dated between 289 and 248 million years old. Fossils of modern Osmunda have been found in Cretaceous sediments dated at about 65 million years. The Osmundaceae family includes four genera: Leptopteris, Todea, Osmundastrum and Osmunda.

Beautiful sterile frond above Osmunda regalis. Is very striking green color, highlighting the aqueous background on which it is rooted. The sterile fronds of this fern in optimal conditions can reach eight feet. (Double click on the photo to enlarge) 

New frond of Osmunda regalis the above, at first it upright stems and leaves as they grow leaning until its tip touches the water. Double clicking on the picture to enlarge you can see the very shaded aquatic habitat where they live. Just behind the frond is an outbreak of Equisetum telmateia. 

Young cultivated Osmunda regalis in the Botanical Garden El Aljibe of the province of Cadiz, which preserves and reproduces this relatively rare botanical treasure in Andalucia.

Frond of fern above cultivated with the feet in the water as he likes. The fronds are lanceolate, bipinnate. The pinnules are oblong and asymmetrical. 

Osmunda regalis sprouting in May after overwintering in the summit crater of a volcano in the center of the island of Faial in the Azores Archipelago, called Caldeira do Faial. To the left of the photo are several flowers of the ericaceae Daboecia azorica, Azorean endemic that grows like a carpet. On the frond are water droplets left by the passage of moisture-laden sea breeze, typical natural Macaronesian phenomenon called Horizontal Rain, which drains several times a day this wonderful archipelago lost in the Atlantic Ocean. 

Osmunda regalis grown in the magnificent Botanical Garden of Faial in the island of the same name of the Azores Archipelago. In this garden is planted in full sun and does not seem to affect him negatively, perhaps because of the high humidity of these Atlantic islands. 

Tender frond newly sprouted with the typical form coiled new growth of all ferns, which follow the Fibonacci mathematical principle. Is appreciated as a web fibrous sac that protects as it expands. The Osmunda regalis is deciduous, it loses its fronds in winter and resprout the following spring. 

Osmunda regalis fertile frond that grows upright and has two types of pinnae, the lower are similar to those of the sterile fronds, while the upper or apical pinnae are formed by groups of sporangia filled with green spores. Sporangia of the photo are still immature. (Double click on the photo to enlarge) 

Beautiful fertile fronds with mature sporangia, photographed in the Jardim Botânico do Faial in mid-May. If we give a small hit with a finger go out a cloud of spores that are dispersed by wind and water.

Another fertile frond of Osmunda regalis with mature sporangia. (Double click on the photo to enlarge)

Details of the sporangia frond above, which, unlike most ferns, not arranged in sori, but develop directly on the midrib of the pinnules.

Monday, February 21, 2011

Asplenoceterach barrancense, a small treasure

It is a hybrid extremely low. In the Soller Valley of Mallorca Island I know only a single individual in a crack in a limestone in the bed of a stream flowing down from the mountains surrounding the valley. Share the crack with one parent, the Ceterach officinarum ssp. officinarum and a Asplenium trichomanes ssp. quadrivalens. In its allotetraploid genome has 50% of chromosomes of Ceterach officinarum ssp. officinarum, 25% of Asplenium fontanum and 25% of Asplenium petrarchae ssp. bivalens. It is therefore a trihybrid with  chromosomes of three different ferns Aspleniaceae family, an allotetraploid with 144 chromosomes (2n = 144, n = 72).

Asplenoceterach barrancense in early June with the new well-developed fronds.

This hybrid was described to science in 1972 by German botanist Dieter E. Bennett and Wilfried Meyer, who gave the name "barrancense" to have found in the Barranco de Biniaraix in the Serra de Tramuntana, Mallorca Island. 

In this picture the three ferns are sharing the same crack: the Asplenoceterach barrancense, its parent Ceterach officinarum ssp. officinarum and a copy of Asplenium trichomanes ssp. quadrivalens.

Habitat of Asplenoceterach barrancense. At the same rock, in a more shaded area, there is a large population of its parent Asplenium majoricum. The torrent remains dry for most of the year. (Double click on the photo to enlarge) 

The probability of a spontaneous hybridization as it is as low as that for a person to touch the first prize in the Euromillions lottery. To place this wonder of nature was no need to fall into the same crack a spore of Asplenium majoricum and Ceterach officinarum. Should then germinate at the same time and give rise to two gametophytes, which were each a female oosphere and many antherozoids. Subsequently an antherozoid one of the two gametophytes swam in soil moisture with the movement of their flagella to the gametophyte oosphere other, that drew him with irresistible aroma of fitoferomone malic acid and fertilization took place. The fertilized oosphere generated a hybrid embryo, the Asplenoceterach barrancense, which grew very slowly until after 3 or 4 years its fronds lean over the edges of the crack.

Combined photography with the family, both parents and child trihybrid

Frond well developed in December. 

Like their parents, the Asplenoceterach barrancense supports the long months of torrid heat and extreme drought of Majorcan summer entering  in aestival lethargy, aestivation, completely dehydrating its fronds, which are rolled, shrink, take on a grayish-brown and appear dead. With the first autumn rains, at 24h, rehydrated fronds, are green, they expand, as if nothing had happened, so much so that the sporangia of sori just grow up and take advantage of the humidity to disperse the spores. 

Underside of two basal pinnae with sori Asplenoceterach barrancense about to mature and paleae covering the petiole, rachis and the underside of the pinnae, the legacy of his father Ceterach officinarum ssp. officinarum. (Double click on the photo to enlarge) 

Microscopic photograph of the rachis with paleae having an intermediate structure between the trichomes or glandular hairs of Asplenium majoricum and large paleae of Ceterach officinarum.

Photomicrograph of the underside of a pinna with sori partly covered by indusium and abundant paleae more narrow and filiform than the Ceterach officinarum. (Double click on the photo to enlarge)

Underside of another Asplenoceterach barrancense pinna of view at 40 magnification. 

Palea of Asplenoceterach barrancense in microns.

Mature Sori very similar to those of its parent Asplenium majoricum. Comparing the size of the frond with thumb that says we get an idea of the tiny size of the fern, which breaks all the schemes of the genetic probability. Its combination chromosome in a similar animal, equivalent to the spontaneous hybridization of a mule (a hybrid between a horse and donkey), which is the Asplenium majoricum, and an African zebra with double chromosome ( impossible between animals, but in plants ), which is the Céterach officinarum ssp. officinarum, autotetraploid of ancestral Asplenium javorkeanum.

Asplenium fontanum--> X <--A.  petrarchae ssp. bivalens            Asplenium javorkeanum
( FF                             (PP)                                                        ( CC )
                              l                                                                                                                           l
                              l                                                                                                                           l
       ( Hibridación interespecífica )                                                                               ( Apomeiosis )
                                                   l                                                                                                                          l                      
                              l                                                                                                                          l
                                V                                                                                                                        V 
            Asplenium majoricum -------> X <------- Ceterach officinarum ssp. officinarum 
  ( FFPP )                                   l                                ( CCCC )
        ( Hibridación interespecífica ) 
                                                 Asplenoceterach barrancense      .........................
                ( FPCC )

Detail of mature sori indusium lifted revealing the sporangia. (Double click on the photo to enlarge) 

Sori of the parents of Asplenoceterach barrancense.

And to finish the proof of sterility, aborted spores, dead and partially decomposed unfeasible. Under the microscope there are very few spores and the few that seem to be practically empty or broken. Cultivating the spores in a lunch box after three years there was no germination.

Saturday, February 12, 2011

Armillaria mellea, a silent killer

The fungus Armillaria mellea is a serious problem in arboriculture, it kills large numbers of trees in both orchards and in afforestation. It all begins with a spore in the wind. If on a small wound in the bark of a tree base sensitive, germinates and begins the nightmare. The germinating spore gives rise to a white mycelium that grows like a web beneath the bark and feeds on the cambium under bark. In its growth has a predilection for roots and respects the bark and branches, ie, attacks the underground parts of the tree.

Mushrooms of Armillaria mellea in November growing on the roots of a tree in the farm Monnaber of the Serra de Tramuntana in Mallorca. (Double click on the picture to enlarge) 

The mycelium continues to grow from the base of the tree towards the main roots, then secondary and finally the finest. If the road is with a root of another tree encroaches too sensitive, so progress to involve large tracts of land, going from tree to tree like an oil slick. It could be called silent killer because it is not, but there is underground killing thousands of trees, shrubs and lianas. 

Armillaria mellea mushrooms tender in November growing on the root surface of a tree in a mixed forest of pines, oaks and olive trees of the Coll de Soller in Mallorca. This image explains why it was given the name "mellea", ie the color of honey. The tender mushrooms hat is covered with darker scales, which fall off as it grows.

The mycelium of a single individual can come to invade several acres, calculated in tonnes total weight of a single fungus. During the summer heat and drought keep it in aestivation, waiting patiently for the first autumn rains. When the land returns to be wet and temperatures are cooler, restart your nourished invasive activity of the cambium of all that live roots in its path. When you have accumulated enough nutrients, in November or December, laden mushrooms produce spores to reproduce. 

Armillaria mellea in December to grow at the base of an apricot. The color of mushrooms varies by plant parasites, ranging from olive, beige, brown or reddish. 

Previous mushroom close-up views. The hat is between 4 and 12 cms. in diameter and is somewhat darker in the center. The shoots of apricot tree was still alive. In late winter, just when it started to sprout and flourish, died struck with the half-open flowers, as their roots could not feed the buds. 

A previous mushrooms seen by the bottom. The foot is very fibrous and slightly darker than the rest of the mushroom. It is appreciated membranous ring around the foot at its closest to the hat. The mushroom gives off a pleasant aroma. 

Armillaria mellea blades decurrent unequal. Its color darkens as they age. Among the films are developed basidium type sporangia, each of which produce 4 spores white, elliptical, maximum diameter no greater than 9 microns. Sporulation is abundant and covered with a white cloth hats that are below. (Double click on the photo to enlarge)

Base of previous apricot mushrooms aside. Emission is abundant rubber as a reaction to the aggression of the fungus. The rubber stops the upward growth of the mycelium, but can not prevent that attack the roots. 

Base of a plum killed by Armillaria mellea. You see the white mycelium under the bark off a strong pungent smell is very characteristic and unpleasant. Plum struck died after spring bud break. 

Armillaria mellea mushrooms growing on the stump of an old rose that killed a year earlier.

Base of a stalk of banana garden, Musa "Orinoco", killed by the stroke of Armillaria mellea mycelium. 

Cross section of stem above completely invaded by the mycelium, which in this herbaceous plant adopts a different arrangement to woody plants. 

Base of the trunk of a Cherimoya, Annona cherimolia, killed by Armillaria mellea. It looks great as the mycelium fails to grow up, while it grows down, invading the cortex of the base of the tree and all roots. You can see the bark still alive in the aerial part of the trunk, and struck the tree died by not receiving water and nutrients that dead roots could not provide. 

Base of the trunk of a mango, Mangifera indica, killed by Armillaria mellea. The tree was 8 years old and had given several abundant crops of fruit. It was very well adapted to the climate of the Valley of Soller, but could not overcome the relentless attack of the fungus. In the picture you see white mycelium after starting a piece of bark. On the right you can also see an infected root. 

Intensely white mycelium handle base above. The smell is so strong and characteristic that once smelled never be forgotten. (Double click on the photo to enlarge) 

Fortunately not all plants succumb to attack by this silent killer, because few have learned to be respected and have gained strength in the form of toxins or antibodies that prevent invasion or destroy the mycelium after they have been attacked. Usually native plants that, after living for millions of years with Armillaria have been adaptive mutations that protect them from fungal attack by fungal toxin synthesis.  

Other plants, although not native, they are able to fight back in the early stages of invasion and destroying fitoanticuerpos produce mycelium. These champions of survival languish for years without even die, the fungus produces mushrooms at the base for three or four autumns, until a spring sprout vigorously, survive the disease and stop producing mushrooms. This dramatic recovery I've seen in avocados, figs, Cryptomeria, palm of fortune, elders, loquat, etc ... 

I had a fig tree "Coll de Dama Negra" I was so upset that for several years gave very few figs, which ripen well, they looked appetizing, but tasted nasty to rot. The leaves were small, yellowish, and in small numbers. Each fall out a good bunch of Armillaria mellea mushrooms at the base of the trunk. One spring there was a miracle and came out big sheets with unusual vigor, in late summer gave a large crop of figs taste great and no more mushrooms out again at its base. It has been 15 years and the fig tree is huge and fully recovered. 

Loquat recovered from the attack by Armillaria mellea. The mycelium was to rot the roots and trunk base. However roots survived emitting sound directly from the bark of the trunk, which have not been attacked by the mycelium which clearly persists in the field and at the rotten roots. In the picture looks very good the rotting remains of the base of the trunk and aerial roots that emerged almost a 10 cms. soil and introduced into the earth to save the tree. The effort had to do was titanic medlar, having no more than a little water and nutrients stored in its trunk and branches dying, which he used with great wisdom to take the aerial roots and saved from certain death. Currently produces large crops of sweet, juicy fruits and appearance is excellent.

Base completely rotten trunk of a willow tree, Sambucus nigra, which also survived a vicious attack of Armillaria. After the sprouting spring began to wilt, leaves turn yellow and fell off in the middle of July. Luckily a few weeks later, in August, it rained for several days and this was what enabled him to survive. Concentrating all the little water and nutrients that he still had in the trunk white rootlets issued directly from the healthy bark, which were introduced recently in the ground moist and miraculously his body in September issued new outbreaks, fed by roots issued. The mycelium of the subsoil and could not attack because the elder had learned his lesson and had synthesized fitoanticuerpos against mycelium. Had autovaccine. 

Despite the apparent evil of Armillaria mellea, it is known that some forest trees that grow in areas infested with the mycelium, not only are not attacked by the fungus, but have learned to benefit from each other in an incredible symbiosis, acting Armillaria as a mycorrhiza. 

Fight this silent killer is totally ineffective. There is no point starting the infected trees, burn their trunks and roots, plowing, treating the soil with fungicides, biological methods used to fight enemies of Armillaria microorganisms entering the field and attack the mycelium. 

Apparently all these methods at first seem to work, but the vast mycelium of several tons, which occupies the ground as a giant underground and invisible web that reaches to cover several acres, is always the best cards to win the game. Cleverly hidden under the protective bark of infested roots or spores remain dormant for years without germinating. Once the danger has passed, when fungicides and have become inactive by oxidation or chemical neutralization or when biological control organisms have died from lack of food (her, its mycelium), then reviving like the phoenix and again do what he does best: killing all plants survive unprotected to be put forward. 

So bad and cunning is the honey mushroom.

Friday, February 11, 2011

Diplazium caudatum, the beauty of the black colour

This beautiful fern is an Iberian-Macaronesian endemic species living in all the islands of Macaronesia: Canary Islands, Azores, Madeira and Cape Verde and in the region of Algeciras in the Cadiz province, including in the Natural Park of Los Alcornocales, which persists a habitat similar to the laurel forest, warm and humid throughout the year. Belongs to the family of Athyriaceae and its genome contains 82 chromosomes (2n = 82, n = 41). It is a relic of the Miocene, like other Iberan-Macaronesian or African-Iberian-Macaronesian ferns, such as Woodwardia radicans, Culcita macrocarpa, Asplenium hemionitis, Davallia canariensis, etc.. During the Tertiary these ferns filled the greater part of the Mediterranean.

Fine example of Diplazium caudatum growing in the Caldeira do Faial in the Azores Archipelago. Double clicking on the picture to enlarge you can see the bright eye-catching black rachis of the fronds, characteristic of this fern.

Diplazium caudatum group growing in shaded, moist slope of a rush of Faial Island. We can see the rhizomes and leaves some alien invasive Hedychium gardneranum, competing for the same habitat and endangers the survival of this beautiful little paleomediterranian fern

Young specimen of Diplazium caudatum grown in the Jardin botanico del Aljibe, located in the town of Alcalá de los Gazules where retain endemic ferns more representative of the laurel forest of Cadiz.

Laurel understory, shady, moist habitat ideal for Macaronesian fern. Photograph taken in the beautiful Bosque de Los Tiles on the Canary island of La Palma. Enlarging the picture with a double click we can see a large population of Diplazium caudatum. These relict forests are impressive silence, broken only by the tinkling of drops of the horizontal rain falling from tops of the trees and the guttural singing the beautiful endemic laurel rabiche and turque pigeons. The air smells good soil, healthy and fresh. It is a pleasure to breathe deeply to oxygenate the blood.

Old copies of Diplazium caudatum of Bosque de Los Tiles. We can see the creeping shoots of endemic Hedera canariensis.

In the Canary Archipelago live in Tenerife, Gran Canaria, La Gomera and La Palma in ravines and forests of laurel permanently damp, shady, deep, between 250 and 800 meters. It needs warm temperatures throughout the year without sudden changes or frost. It is classified as vulnerable on the IUCN Red List of Spanish Vascular Flora of 2008.

Beautiful new Diplazium caudatum frond can reach 190 cm, which makes this fern in the third largest in the Macaronesia, behind Woodwardia radicans and Culcita macrocarpa. We can see how the black spine is changing to green as it approaches the apex of the blade. On its underside the black color reaches almost to the apex. The blade is ovate or ovate-lanceolate, tripinnate and glabrous on both sides, dark green when fully developed.

In this picture we can see the long thin caudate or acuminate apex of the pinnae, detail for which was given the name "caudatum". (Double click on the photo to enlarge)

Details of the pinnules of Diplazium caudatum. It is very striking and bright deep black color of the spine, which changes to green as it approaches the apex of the blade and pinnae.

Detail of the spine stained black and shiny. (Double click on the photo to enlarge)

Long shiny and black petioles, blackish brown or brown-green of Diplazium caudatum, which can exceed the 80 cms. and are shorter than the blade. At the bottom are covered with dark-brown and opaque paleae. The rhizome is creeping and may reach up to 40 cms. long and 10 cms. in diameter in older individuals. Sprout fronds at intervals of 1 cm. each other.

Immature oblong sori of Diplazium caudatum with the indusium not yet lifted, arranged in two parallel rows along the midrib of each pinnules.

Mature sori with raised indusium and deployed sporangia, dispersing the spores.

Sporangium of Diplazium caudatum with the bag ripped, but still without dispersing spores.

Diplazium caudatum spores under the microscope at 400 magnification.

Diplazium caudatum spores germinate easily. In the picture we can see a small staff of young specimens newly transplanted to individual flowerpots, from spores of the fern of the first picture of this article. The strongest who survived the transplant, donated to the Botanical Garden of Soller to enrich its magnificent collection of Macaronesian plants.