Sunday, March 13, 2011

Davallia canariensis, the Macaronesian rhizomatous fern

It is a fern lover of light, mild temperatures and frost-free rather dry acid soil. Not support the shade or excessive moisture. Its rhizomes succulent full of water and nutrients help to withstand long periods of drought. I like living on rocks covered with moss and lichens and also as an epiphyte, especially oaks, holm oaks, cork oaks and laurel trees, as garoés, barbusanos, Viñátigo and laurels. Its adaptability also allows clear walls and colonize faial-heath. It ranges Galicia, Asturias, northern Portugal, Cadiz, Madeira and the Canary Islands. Belongs to the family of Davalliaceae and chromosome is 2n = 80. 

Several copies of Davallia canariensis growing in full sun among the stones of a wall of the Villa de Mazo on the island of La Palma. 

In Andalusia, Davallia canariensis is protected by law and the cork corkscrews respect it when found growing as an epiphyte on the cork. The image has its roots tucked between the ridges of cork. Photo taken in the Natural Park of Los Alcornocales in the Cadiz province near the town of Jimena de la Frontera. 

Davallia canariensis group on a wall of volcanic rock of Los Llanos in the island of La Palma. Are several fronds of endemic Polypodium cambricum ssp. macaronesicum. 

Davallia canariensis growing as an epiphyte on a Canary Island date palm, Phoenix canariensis, in the municipality of Barlovento north of the island of La Palma.

Davallia canariensis growing as an epiphyte on a high branch of Garoe, Til or Arbol-fuente, Ocotea foetens, in the lush Bosque de Los Tiles of the Island of La Palma.

This fern also lives in the forest clearings of faial-brezal, like the photo was taken in the town of Los Llanos de Aridane. 

Young Davallia canariensis with rhizome rooted in the moss on a rock of Monte Poiso Madeira Island. The rhizome of this fern grows on the substrate surface always, never shed, because moisture does not support. He needs to touch the air and light. Can measure up to 2 cm in diameter. From the bottom, which is in contact with the ground, sprouting roots that set the rhizome, which is growing and branching out so that it can form a small colony with multiple shoots, all from a single individual.

Details of previous rhizome paleas covered up to 12 mm long, lanceolate, glossy, hyaline and ciliate margin. As it grows and branches to form buds sprout fronds that can reach 50 cm in length, with the petiole as long as the blade, red-brown, paleae covered, darker at the base. The petiole is seen in the picture is green because it belongs to a frond still tender. It will darken as time passes. 

Davallia canariensis fronds with 3-4 pinnate blade, subdeltoid, glabrous, with the last order segments lanceolate or ovate-oblong, dark green, lighter in the tender fronds. 

Davallia canariensis sori, apical submarginal, at the end of the nerves, with cup-shaped indusium.

Sporangium of Davallia canariensis now empty after the dispersal of spores. .

 
 A long sporangiophore sporangium of Davallia canariensis, which serves as the umbilical cord. It consists of several tubular cells and binds the sporangium to the pinnules, which supplies water and nutrients the sporangiophore sporangium takes the ring, which has a function similar to the mammalian placenta and nourish the spores while growing inside the bag of the sporangium. 

Davallia canariensis spores oblong-reniform, hyaline, large, a beautiful lemon-yellow color.



Sunday, March 6, 2011

Phyllitis scolopendrium, deer tongue

Deer's tongue, Phyllitis scolopendrium synonymous with Asplenium scolopendrium owes its popular name to the shape of their fronds that look like long, narrow tongue of the deer. Its scientific name is composed of a Greek word "Phyllitis" of phyllon, meaning leaf, by its  simple and not pinnate fronds and a Latin word "scolopendrium" which refers to the shape of its fronds centipede, which tend to be similar to undulations of the body segments of the worm. Belongs to the great family of the Aspleniaceae. Its chromosome number is diploid with 2n = 72, n = 36. 

Copy of deer tongue grown in the Botanical Garden of Soller on the island of Mallorca. On this island Phyllitis scolopendrium fern is extremely low. The mother's copy of the photo, from which spores were obtained for culture, lives in a deep ditch in a vertical cave in Majorca called "Sa Cova des cero" (The Deer Cave) that is in the Serra de Na Burguesa. To access the ferns should be climbing down with ropes. Only under these conditions of humidity and permanent shadow survives the hot and dry summers of Mallorca. 

Unlike the exemplary Mallorca, this vigorous Phyllitis scolopendrium lives in broad daylight in a clearing in a laurel forest of the island of Faial in the Azores Archipelago. These Atlantic islands enjoy a warm and humid climate throughout the year thanks to a constant supply of moisture from the horizontal rain, typical of the Macaronesia. Particularly striking is the mark of sori in the face of the fronds, which gives them a segmented or striatum. 

Two other individuals on a slope of the volcano crater called Caldeira do Faial in the Azores. To the left are several sheets of the Azorean endemism Hedera azorica and right down a few fronds of invasive alien Deparia petersenii.
The Phyllitis scolopendrium live in Europe, the Mediterranean, the Azores and Madeira. The farther south than its presence is rare. Their preferred habitat is forests, caverns, caves, ravines, gullies and shady and cool walls with constant humidity throughout the year. 


One of the characteristics of the Phyllitis scolopendrium the base cordate with rounded divaricated auricula and petiole no shorter than the lamina, which is lanceolate in adult and oblong-lanceolate in young copies and can reach up to 60 cms. The base with rounded and not divaricated auricula distinguish it from the Phyllitis sagittata, which in the adult specimens usually have acute and divaricated. .

Underside of a frond with large mature sori arranged parallel to each side of midrib of the blade. 

Detail of linear, parallel to each other and unequal sori that can reach up to 3 cm. Indusium entire margin in the photo is not because it has been opened and the sporangia are deployed, towering above the indusium.

Sporangium of Phyllitis scolopendrium already deployed with the empty bag after the dispersal of spores.

Small spores deer tongue. Its size is generally not exceed 33 microns, which indicates a diploid ferns.

Tiny sporophytes of Phyllitis scolopendrium with his first frond, which has sprung from a fertilized oosphere of a gametophyte. 

Luxuriant population of Phyllitis scolopendrium gametophytes after mass germination of spores dispersed sporangia of an old copy which is a few meters above. Picture taken at Caldeira do Faial in the Azores. They are some sporophytes with fronds at different stages of growth.