Sunday, February 6, 2011

It loves the sources built by the Moors


At the black maidenhair fern, Adiantum capillus-veneris, likes to live with the roots in water, so the spores germinate only if they fall on a permanently wet floor or wall, wells, fountains, aqueducts, canals,  oozing rocks and walls, banks of rivers and streams, reservoirs exterior walls, etc ... Usually forms a large colony with many individuals growing together as a hanging hair. Belongs to the family of Adiantaceae. Its genome contains 60 chromosomes (2n = 60, n = 30).  
 
 
Hanging fronds of Adiantum capillus-veneris in a dripping wall of a terrace of Soller Valley on the island of Mallorca. 

Black maidenhair beautiful hair covering this endearing fountain in the gardens of The Alcazar of Seville. (Double click on the photo to enlarge) 

Adiantum capillus-veneris has a radicant rhizome that grows horizontally and is densely covered with brown linear paleae. Its fronds, depending on the degree of light they receive, may be more or less long, reaching 50 cms. The petiole and rachis are black, sometimes brown-blackish, with a vivid bright of jet and very brittle. The blade is ovate-lanceolate with light green pinnae and delicate texture. Running the hand over the hair that form their fronds we notice his smoothness and softness. Formerly used in syrups and infusions to treat respiratory problems for its expectorant properties.

 Former fountain with black maidenhair built during the Muslim domination of the Balearic Islands for over 800 years, located in the beautiful Arabian Gardens of Alfabia in the Mallorcan town of Bunyola

The Adiantum capillus-veneris is widely distributed cosmopolitan, growing in tropical, subtropical and temperate zones of all the earth, which indicates its high adaptive capacity.

Close-up image of the previous source of green adorned by a large colony of Adiantum capillus-veneris. (Double click on the photo to enlarge) 

Beautiful dressed in green Arabic source in the Partal Gardens of the Palacios Nazaries of the Alhambra in Granada. It is very striking the tendency of this fern to live in sources. (Double click on the photo to enlarge)

Another ancient fountain built during the Muslim domination of Mallorca, located in the village of Randa, in a fertile valley at the foot of a small mountain in the center of the island. The ferns have their roots anchored in the thick layer of moss.

Irrigation canal collects water from the previous source, locally called Font de Randa, with a large colony of Adiantum capillus-veneris. Mallorca Arabs who built the fountain and the irrigation canals more than 8 centuries dominated the art of using water. It is only fair to acknowledge the great legacy left to those who expelled them from their beloved island. With the near certainty to take a little blood in my veins arrears of almost 3,000 descendants of the Moors Mallorcan left as slaves in their own land and were forced to be baptized, I dedicate this article in appreciation of the immense work done by converting a dry and unproductive island in an orchard

Black maidenhair ferns growing on the rocks bordering the Torrent Biniaraix in the Serra de Tramuntana in Mallorca. (Double click on the photo to enlarge).

Adiantum capillus-veneris between the stones of a bank of a banana of Tazacorte on the Canary island of La Palma. 

Fine specimen of Adiantum capillus-veneris with deeply lobed pinnae growing on the rocks bordering the Torrent de Pareis of Sa Calobra on the northwest coast of Mallorca.

 
Typical pinnae of black maidenhair fern. Each pinna is divided into several pinnules separated by a notch. Picture taken in a garden of Mallorcan town of Sóller. 

Underside of the pinnae of the previous photo with immature sori covered by a false membranaceous indusium, pseudoindusium, inserted at the edge of the pinnules. 

Mature sori, one on each pinnules, with raised pseudoindusium exposing the sporangia, which are already being deployed and dispersed the spores. Shows the lattice structure of the pinnae fan-shaped, typical of the genus Adiantum. 

Microscopic photograph of a sporangium of Adiantum capillus-veneris, now empty after the dispersal of spores. You can see the torn bag containing the spores. 

Trilete spores, tetrahedral-globose, finely granular of Adiantum capillus-veneris. Draws attention to its beautiful golden color.









Friday, February 4, 2011

Woodwardia radicans, the giant of laurel forest


Woodwardia radicans is the largest fern of laurel forests. Their fronds can reach 2.5 meters in length, beating the other giant, Culcita macrocarpa. Precisely these two large ferns, along with Selaginella balansae, are considered the oldest settled during the Late Cretaceous in the western Mediterranean region from ancient African and Asian ferns, perhaps over a period of warm subtropical climate. Its current natural distribution seems to support this hypothesis, since it lives in the Macaronesian Islands: Canary Islands, Madeira and Azores (except in the Cape Verde Islands), the Cantabrian-Atlantic coast of the Iberian peninsula: Galicia, Asturias, Cantabria and Basque country, in northern Algeria and also in the south of the Italian peninsula, Sicily, Corsica and Crete. Existing populations in the Serra de Sintra in Portugal are not natural.

Beautiful example of Woodwardia radicans in a clearing of a laurel forest of Madeira Island near Funchal at the beginning of May. (Double click on the photo to enlarge)

Because of its great beauty has been cultivated in many countries around the world, existing feral populations in Asia and North America, for example, in Florida and California. Belongs to the family of Blechnaceae, like the Doodia caudata, the Blechnum brasiliense and Blechnum spicant. Its chromosome number is 2n = 68. The genus Woodwardia was devoted to English botanist Thomas J. Woodward (1745-1820), specialized in cryptogamic plants.

In the Canary Islands it is called Pijara, Penco labrado, Pirgua and Helecho de cumbre, in Portugal is called Feto de botâo and in Galicia Feto de botón, in Italia Felce bulbifera and in English Chain fern or Rooting chainfern.

Its scientific name refers to the ability of this fern to reproduce vegetatively from small bulblets, buds and shoots, that as small rhizomes brown paleae covered grow in the apical end of the fronds. When these bulblets come into contact with the ground, take root and begin to grow as independent ferns. Thus botanists gave it the name "radicans" =  that takes roots.

Great Woodwardia radicans fronds hanging on the wall of a ravine of Bosque de los Tiles on the island of La Palma. The older fronds were arching to looking for a contact point on the land of the wall and then the small bulblets that grows at the end of the frond takes root and gives rise to a new identical clonal fern his mother.

Their preferred habitat are the moist and shady ravines and forests, both vertical walls, as in the understory and in deep crevices of rocks. In the Cantabrian coast, when massive forest clearing and the forest is naked without the protective cover from the tops of the trees, Woodwardia are left to frost and die with fronds burned from the cold.

Three young specimens of Woodwardia radicans in the northwest slope of the volcanic mountain called Caldeira do Faial in the island of the same name of the Azores Archipelago. Can see the thick brown rhizome paleae covered.

Impressive frond of two meters long hanging in the Bosque de los Tiles on the Canary island of La Palma. The blade is ovate-lanceolate, sometimes triangular, caudate pinnae more than 30 cms. The pinnules are subfalcate slightly serrulated. (Double click on the photo to enlarge)

Woodwardia radicans new frond displaying their pinnae in early May.

Here you can see the reason for the name "radicans", a bud or bulbil that grow on the tips of the fronds and when it touches the ground it takes root and gives rise to a new fern. In this way it can produce an entire population of Woodwardia radicans genetically identical to the original fern that was born from a spore.

This photo shows bulbils already rooted in the tip of a frond of Woodwardia radicans grown in a garden of Mallorca. These clonic shoots can be left grow around their mother or are cut from the frond and transplanted to another site partially shaded and sheltered from cold winds from the north. In summer, they need regular watering if it not rains. For cutting and transplanting is not necessary to wait to take root. You can also put a flowerpot near the mother holding the bulblets on the ground of the flowerpot and, when it is rooted, already you can cut the tip of the frond.


Same small bulbil after planted. A few weeks begin to sprout new fronds and two years after reaching maturity.

Woodwardia radicans mature sori in January with the indusium sporangia up to be deployed and disperse the spores.

Details of previous sori, which are typical of the family Blechnaceae and are embedded deep into the underside of the pinnae, forming two parallel rows attached to the midrib of each pinna. Double clicking on the photo for a larger look great displayed sporangia, peeking below the convex and leathery indusium.

Microscopic photograph of a sporangium of Woodwardia radicans now empty after the dispersal of spores. Above left is the sporangiophore formed by  tubular cells, which is attached to the pinna and makes the role of umbilical cord, feeding the sporangium which form the spores in the transparent bag.

Dark yellowish spores of Woodwardia radicans with subreticulated perispore, viewed to the microscope at 400 magnification.