Ceterach lolegnamense, with two mutations it was turned fertil

Ceterach lolegnamense fern, also called Asplenium lolegnamense, is an endemism of Madeira absolutely amazing. For its status of allohexaploid hybrid should be sterile and die without issue but managed to evade his fate and survived by two mutations that laugh at the laws of genetics, Apomeiosis or absence of meiosis in the sporangia, resulting in hexaploid spores perfectly viable and Apogamy or Gametophytic Apomixis allowing it to produce a new fern from a somatic cell of the gametophyte, skipping fertilization because their gametes are not viable.

Ceterach lolegnamense in a very damp and shady wall oriented toward the northwest located on the road to Curral das Freiras. Is rooted on a bed of moss, lichen and Selaginella denticulata, which act like a sponge and keep the soil constantly moist. It is very striking resemblance to its ancestor Ceterach aureum.

Interestingly, despite being endemic to Madeira, its origin seems to be in the nearby Canary Islands. Both parents, the allotetraploid Ceterach aureum (Asplenium aureum) and the allo-octoploid Ceterach octoploideum (Asplenium octoploideum synonymous with Ceterach aureum subsp. Parvifolium) only live in the Canaries. It is assumed that several million years ago, perhaps during the Messinian period of Miocene, the spores were able to get to Madeira, or carried by wind or glued to the feathers and feet of sea birds, capable of germinating on the volcanic lava populate this beautiful Portuguese island. It ignores the reasons for the extinction in the Canary Islands.

In its genome is a curious combination of chromosomes from two primordial ancestors: the 66'66% of their genes from its diploid grandfather-great grandfather Ceterach javorkeanum, also called Asplenium javorkeanum, confined for millions of years in the Italian peninsula, the Balkans, Sicily and Turkey and 33'33% from its other diploid grandfather-great grandfather Asplenium semi-aureum, now considered extinct, but their genes survive in their hybrid offspring.

Family tree of the subgenus Ceterach ferns in the shape of their fronds. Drawing taken from the excellent article "Phylogenetic analysis of Asplenium subgenus Ceterach (Pteridophyta: Aspleniaceae) based on plastid and nuclear ribosomal ITS DNA sequences". http://www.amjbot.org/cgi/content/full/90/3/481

Another beautiful example of Ceterach lolegnamense in the same location as above.

  The thick layer of Selaginella denticulata seems to be almost essential for survival. If we start a bit of substrate is to be formed by the decomposed fronds of Selaginella denticulata mixed with remains of mosses and lichens and a few pieces of volcanic lava. The Selaginella denticulata, like plants that produce the mob lives on decomposing waste itself.

 Along with this group of Asplenium lolegnamense can see multiple copies of the Macaronesian endemism Aichryson villosum, a Crassulaceae, to bloom in early May.

New frond of Ceterach lolegnamense in early May. The pinnae are more slender than its parent Ceterach octoploideum.

 Frond last year with a beautiful yellow-green, a legacy of its father Ceterach aureum.

Sori still immature almost invisible under the thick layer of yellowish-white paleae lining the underside of the frond.

Mature sori in early May with conspicuous black sporangia about to disperse the spores. Enlarging the picture by double-clicking the details are better appreciated.

Mature sori after spore dispersal. Sporangia are appreciated and made of brown, protruding above the paleae.

Paleae of Ceterach lolegnamense, formed by a layer of dead and empty cells.

Sporangium of Ceterach lolegnamense with its ring of fire red cells and the bag ripped after spore dispersal.

Ceterach lolegnamense spores of a rather large size, characteristic of polyploid ferns. The spores of the diploid fern family Aspleniaceae never rarely exceed 39 μ, as in Asplenium javorkeanum, one of its ancestors.

Dryopteris guanchica, an allotetraploid hybrid fern of Miocene

The Miocene was the cradle of a large number of existing plants, many of them the result of interspecific hybridization and subsequent successful adaptive mutations that allowed them to survive the sudden changes of that tumultuous period. One of these plants is the fern Dryopteris guanchica, an allotetraploid hybrid fruit cross between Dryopteris aemula and Dryopteris maderensis. Belongs to the family of Aspidiaceae. Its chromosome number is 2n = 164, n = 82.

Magnificent specimen of Dryopteris guanchica in early May in the path of Vueltas de Taganana in Anaga Massif located in the far north of the island of Tenerife. The fern was old fronds and new fronds, having just sprouting spring issue. The Dryopteris guanchica, like most ferns arose during the Miocene, it grows in the Macaronesian region and the Iberian Peninsula (humid forests of Northern Spain, Galicia, Sierra de Sintra and Sierras de Algeciras), in one day was a vast region covered with forests of laurel. About 6 million years ago, during a very cold and dry period in that the water of Atlantic Ocean descended about 100 meters below the current level (in the Great Messinian salinity crisis that lasted a million years), land shallower European and African coasts and the Macaronesian islands emerged out of the sea and, having little water to separate them, facilitated the exchange of plant and animal species and interspecific hybridization between related plants. This allows us to understand why the genes of an endemic fern to Madeira, the Dryopteris maderensis, found on a fern Dryopteris guanchica as in regions as distant from Madeira. Dryopteris guanchica curiously does not grow in this beautiful Portuguese island, where live nevertheless both diploid parents, Dryopteris aemula and Dryopteris maderensis.

Another issue of Dryopteris guanchica on the same path of Taganana Turns. We will see the new fronds sprouting vigorously. The photos are very bright due to camera flash, as really living in a twilight intense in the understory of a thick, almost impenetrable rain forest of laurel. Dryopteris guanchica is one of the most demanding habitat type of Aspidiaceae, then it need to live in a very dark habitat on a acid substrate permanently wet. Other Aspidiaceae of Anaga Massif as Dryopteris oligodonta and Polystichum setiferum are less demanding environments and can tolerate more light and less humid.

 Dryopteris guanchica in the forest track along the trail of Pijaral that goes from Roque Anambra to the viewpoint of Cabezo del Tejo. In the Canary Islands, besides Dryopteris guanchica, grows also its ancestor Dryopteris aemula, as well as Dryopteris affinis and Dryopteris oligodonta. Some botanists say they have found also Dryopteris maderensis in the Canaries, but in any case would be very few copies. Its existence outside of Madeira could be explained by recent colonization by spores carried by wind or stuck in the feathers and feet of sea birds or an old land-land settlement during the Messinian period in that the Canary archipelago and maderense archipelago sometime came to form a continuum without water than separated.

Wide triangular-lanceolate frond of Dryopteris guanchica an intense dark green color, soft touch and consistency pinnae very crisp tender. Can reach 115 cm in length. Its petiole yellowish-brown with abundant brown lanceolate paleae in their basal part is longer than the blade.

The frond of Dryopteris guanchica consists of asymmetrical pinnae especially the pair of basal pinnae frond (seen in the photo below), as acroscopic pinnules are less developed than basiscopic. Both the rachis of the frond and rachis of the pinnae and the pinnules are grooved on its upper surface along its entire length.

In this new clear color frond can be seen perfectly the asymmetry of the basal pinnules clearly larger the basiscopic than the acroscopic.

The pinnae are divided three to four times in petiolulate pinnules, triangular-lanceolate, with serrated edge and corner teeth convergent or directed toward the apex of the pinnules. It looks great channel that runs along the top of the spine.

 Immature sori of Dryopteris guanchica in early May. Enlarging the picture double click the details look better.

All Dryopteris sori are reniform (kidney shaped). In the photo of these immature sori we see the white and transparent indusium that covers the sporangia.

Dryopteris guanchica mature sori in early May. These sori matured at the end of last summer and the sporangia have already dispersed spores.

 In these mature sori the indusium is looming up leaving the tiny sporangia months ago deployed and dispersed the spores at the optimum time for germination.