Monday, June 27, 2011

Ceratonia siliqua, the fodder of Lapland reindeers

Indeed, the reindeers that throw of the sleighs of Lapland´s Eskimos feed on the nutritious sheaths of the carob tree, Ceratonia siliqua, a leguminous arboreal tree cultivated for several millenia in all the coastal zones that border the Mediterranean Sea. The poor and monotonous diet of the reindeers with coriaceous Arctic lichens complement themselves successful with triturated sheaths of the carob beans. The hard seeds were separated to use them like thickeners in the human feeding, pharmaceutical products and the chemical industry.   

Old and imposing carob tree of more than 150 years seeded by my great-grandfather in a cereal field of Majorca. It surpasses the 12 meters of height and its trunk measures more of a meter of diameter. During its long life it has given abundant harvests of carob beans. Making a simple calculation, if a normal year produces between 200 and 400 kilos of fruits, multiplying it by last the 130 years of its adult life, it gives a total of 40 tons of carob beans.

On the other hand, the mycorhizes of their roots in their average century and of life have fixed several hundreds of kilos of atmospheric nitrogen in the form of underground nodules that have enriched the poor, argillaceous, calcareous and stony ground where the roots are introduced.

Every spring is born several broods from small birds in the nests that the birds construct on their branches. A pair of hoopoes year after year takes advantage of a hole in the doubling trunk to bring to world one or two broods. The carob tree is, really, a complete ecosystem where hundreds of species of insects, arachnids, birds, small lizards and rodents find a comfortable habitat where to live, to feed themselves and to procreate.

Its dense foliage of dark and coriaceous leaves has given shade to my ancestors during many decades. At noon they sat down, we sat down, in the ground on coats of stuffed esparto of straw in the fresh shade of the old carob tree to eat bread with tomato, salt and olive oil, accompanied by sobrasada, parched cheese, botifarrones, camaiot, bacon roast on live coals, olives flavored with salt and fennel and a few figs dessert droughts, all this watered with a jet of red wine of own production drunk directly of a pumpkin of slim waist, Lagenaria siceraria, with a cork done with a small branch of olive tree. Memory with nostalgy the many sweet hours that I happened playing under this tree in my childhood and the flavorful thing and that felt like their carob beans to me. A pair of them filled the stomach to me and they cleared the hunger to me. They were my picnic. It accompanied sometimes them with some crude almond, that I cracked on a stone.

Carob tree of about 30 years loaded of still green fruits at the height of summer. These trees usually seed themselves in poor lands where they prosper without problems. Sometimes they are combined with other fruit trees like the fig trees, the almonds tree, the olive trees, the plum trees and the apricot trees, all of them very rustic trees that support well  poor and stony soil.

The carob tree is original of the Eastern Mediterranean. The Phoenicians and the Arabs extended their culture by all the Mediterranean river basin. It is a very resistant tree that supports very well the drought and the torrid sun of the summer. It prefers the good drained limestone grounds since their roots do not support flooded lands. The micorrhizal symbiontic fungi that surround their roots need to breathe to live. The static water prevents the soil oxygenation and drowns to the symbiotic fungi. Without filamentous and white hyphae of the fungus, the carob tree cannot absorb the water and the minerals of the ground and the nodules by the roots cannot fix the nitrogen of the air. It is understood since this enormous leguminous support better one releases drought that the water suspended in its roots, which would drown the micorrhizal fungi and it would suppose the death of the tree by starvation.

This dependency easily verifies when seeding seeds of Ceratonia siliqua in individual flowerpots. If the land of the flowerpot lacks spores of the symbiotic fungus, the small tree just born, after consuming the nutrients that the seed contained, stops growing, yellows, it languishes slowly and it ends up dying. In order to avoid that the young carob tree dies literally of hunger, it is sufficient with adding to the flowerpot a little earth picked up of underneath an old carob tree that contains thousands of spores of the symbiotic fungus, which germinate quickly, his hyphae surrounds the roots of the dying little tree and in few days the miracle takes place. The apical yolk appears vigorously and its growth is spectacular. If a few months later migrates the little tree to a greater flowerpot, is verified like its roots are surrounded by a species of white spiderwebs that smell of good earth. They are hyphae of the micorrhizal symbiontic fungi. Also small stuck gray small balls are the roots. They are the nodules locking devices of atmospheric nitrogen that contribute natural installment to the carob tree.

Bipennate leaves of carob tree, brilliants and coriáceas like of plastic, that is darkened as they age and they persist on the tree during several years before falling. The nutrients that contain incorporate to the ground when being disturbed they enrich and it and they puff up. Each leaf is formed by 5 pairs of leaflets. Raquis and the petiole of the tender leaves and the stem of the new buds have an alive dark pink color. 

Still immature carob beans in the middle of the summer. In this state they contain many bitter and astringent tannins that they avoid that the herbivores eat them before their complete maturation.

Branches of Ceratonia siliqua loaded of mature carob beans at the end of the summer. Usually they fall by themselves at the beginning of the autumn, but it is preferable to knock down them with twig blows at the end of summer on ample fabrics prepared under the tree, so that the first rains of the autumn do not rot them.

Fleshy cases of carob tree of a beautiful dark brown color at the beginning of the autumn. Usually they measure between 15 and 25 centimeters in length. The brown pulp that surrounds the seeds is very rich in sugars (until a 30%), proteins, fats, vitamins, pectine, mucilage and tannins. The reason is understood by which most of the production of carob beans of Majorca is exported towards Finland to feed the reindeer of Laponia, since they constitute an excellent very complete and nutritious fodder.

The pulp also is used in confectioner's like substitute of the chocolate. Mixed with wheat flour rich very spongy buns take control of her. The modern ices-cream dealer include the flour of carob bean in their chocolate ice creams and most bold they exclusively make ice creams of carob bean. Also an excellent sweet liquor can be done almost black letting ferment the flour dissolved in water to which grape grains are added to him to contribute necessary leavenings for the fermentation.

The carod seeds, calls "garrofines", are very hard and are surrounded by one cuticle shining raincoat to the humidity. This makes very refractory to the germination and at the same time it allows them to conserve his viability during 4 or 5 years. In the nature a short cut exists to accelerate the germination of the seeds: the passage by the alimentary canal of the herbivores that swallow them whole when not being able them to chew and disperses soon them with their lees. The acid of its gastric juice dissolves hard cuticle partially and facilitates the later hydration of the embryo that germinates quickly.

In the zone of Spanish Levante, for the production of establishments of carob trees in the breeding grounds, usually they are used the seeds gathered of the excrements of the cattle, since one knows that its germination is almost of the 100%. In industrial arboriculture on a large scale it is put under the seeds to the action of a sulfuric acid solution concentrated during one or two hours. Another method to break cuticle and to make it permeable to the water consists of submerging garrofines in boiling water and leaving them in soaking while it cools off during 24 - 48 hours. A simple very effective homemade method consists of cutting to a small piece of cuticle with a nail clippers to each carod seed in the cleared part opposed the germinal yolk. This simple method less than accelerates the germination in 10 days.

Carod seeds have a very uniform size and a weight. This characteristic drew attention of the old Arab and Jewish jewelers, used who them as unit of weight for their transactions of gold and precious stones. KIRAT called it with the Arab word = Carat. From KERATONIA comes the scientific name there to him = Ceratonia, that is to say, tree of the carats.

The carob trees can be masculine, feminine and hermaphrodite. Generally the nurserymen reject the masculine feet or graft by the methods of small shield or Majorcan chip with feminine or hermaphrodite yolks. Knowing him sexuality the carob tree is intelligent intercalary some masculine copy in the plantations from feminine carod trees. 

Inflorescences in the form of swab of a carob tree of masculine sex composed by finished lengths stamens in yellow anthers full of pollen, that leave in groups of six small cleared bases formed by the nectaries.

Masculine inflorescence of Ceratonia siliqua. The red central stem is seen very well del that they leave the cleared nectaries, each one of as surrounded by 6 stamens and its respective yellow anthers. The abundant nectar of the nectaries attracts the pollenizer insects, coverall to the bees that produce an excellent dark honey. I recommend to extend the photo with a double click. 

Inflorescences of a feminine carob tree, with the flowers without petals that leave a red central stem. Each flower has a nectary in its base, del that slightly arises pistilo curved and finished in a heavy sticky stigma, on whose surface stick grains of pollen transported by the bees.

Another feminine inflorescence at the end of summer, with the flowering slightly more delayed than the previous ones, because the nectaries without unfolding and nectar are still seen. 

Inflorescences of a hermaphrodite carob tree with stamens and pistils distributed throughout the red central stem. In order to avoid the self-fertilization, in the first place the feminine flowers with their nectaries filled with rich nectar are opened to attract the bees with the body covered with the pollen of the masculine flowers of another carob tree.

Another hermaphrodite inflorescence in feminine phase. Masculine stamens remains without developing with closed anthers to avoid the self-fertilization. The feminine stigmata wait for grains of pollen taken by the bees. Once the majority of feminine flowers has been fertilized, the stigmata are closed hermetically, their nectaries stop producing nectar and the growth of the small fruits begins.

After the fertilization of the feminine flowers, the masculine phase in the hermaphrodite inflorescences begins. Stamens are extended and the anthers of their ends are opened and begun to disperse pollen. In their base the nectaries produce abundant nectar so that the bees go and the pollen grains take on their body towards the stigma of the feminine flowers of another carob tree, feminine ones as hermaphrodite ones.

Detail of a hermaphrodite flower in feminine phase with the base round and flattened of the nectary with five stamens and the pistil. Stamens get ready around the nectary with orange anthers in their end. Pistil arises from the center of the nectary with a long curved style and the receiving stigma of pollen in its end.

The maturation of the fruits agrees with the flowering. In the photo the mature inflorescences of a feminine carob tree and their fruits at the end of the summer are seen.

After several decades of declivity in their culture, in the last years become to seed young, single or mixed carob trees with olive trees, almond trees and fig trees, because its operation is a business with few expenses and little manpower that can be profitable as of the second decade of the life of the trees. 

Sunday, June 19, 2011

Extrafloral nectaries, a candy for ants

The nectaries are vegetal organs that produce secretions rich in sugars, fats or amino acids or a combination thereof. They can be floral nectaries secreting nectar from flowers and extrafloral more geared to reward the insects that defend the plant from herbivores. 

Tiny extrafloral nectaries in the internode of the stem of a shrub of the red variety castor, Ricinus communis var. sanguineus. In each of them can see the stoma or navel-shaped opening through which a droplet of nectar secreted when stimulated by touch from the jaws of an ant. This detail is best zoom with a double click.

The extrafloral nectaries appeared millions of years long before the first primitive plants develop flowers. It is believed that its formation was initiated by a need for plants excrete excess sap, either through the stomata or pores of the leaves or the microtubules of the glandular hairs or trichomes. Over millions of years of evolution plants learned they could use this excess sap their advantage with two very different purposes:

A-The first purpose was to fend off enemies in association with the ants in an intelligent symbiosis. It all started when the ants in his eternal wandering in search of food found droplets of sap that had to excrete excess plant. Tried it and liked it, so that gradually his visits to the source of sap became more frequent. For a simple rule of economic transaction: I give you what you want to change what you have and I will, slowly excreted sap was concentrated more and more becoming sweeter and richer in amino acids and lipids. At the same time the ants were becoming increasingly dependent on this valuable source of food until they could no longer survive without it.

 Another image of the extrafloral nectaries of castor plant. The symbiosis with ants is not complete, since their nourishment does not depend exclusively on nectar, but manages to rise to their branches and go through all the leaves and shoots, deterring phytophagous insects that are immune to castor poison. Herbivorous mammals avoid eating this plant because they instinctively know it is toxic.

Male flowers castor accompanied by small extrafloral nectaries. This plant has a anemophilous fertilization dependent wind carrying pollen from male flowers of a plant to female flowers of another plant. To avoid self-pollination the female flowers of each inflorescence open earlier than male ones, so that when castor plant emits its own pollen the female flowers are fertilized and are not receptive. At the top of the image are immature fruit of the female flowers that were fertilized a few days before the pollen of another castor.

Some plants went so far as to develop special structures so that the ants could live on them. They were having a private army of soldiers in permanent monitoring. Thus, some tropical orchids have developed cavities in their rhizome specially designed so that the ants can live comfortably in them. The nectar of the extrafloral nectaries containing a combination of nutrients ideal and complete them and no longer need to leave the orchid to get food. Thus the symbiotic ants receive food and shelter in exchange for defense services. 

Some acacias have swollen and hollowed their spines to make them the ideal habitat for the tiny ants that live in symbiosis on them. A small opening in the spine makes the role of gateway to the swarm of hard cellulose. Ants continuously patrol all the branches and leaves of the acacia to detect any enemy, from a simple phytophagous grasshoppers to rough tongue of a gazelle that likes the nutritious young leaves of the acacia. Through the issuance of special ant pheromones alert a colony of the enemy attack and go angry to defend his home and food source. The bites of their strong jaws and squirts formic acid caustic throwing with unusual force by the end of their abdomen deter the grasshopper and quiet gazelle acacia leaves. No symbiotic ants that defend the acacias are rapidly eliminated by the army of hungry mouths to inhabit the arid savannas.

B-The second purpose of the nectaries was to attract insects, birds, reptiles and mammals into the primitive flowers thus facilitating genetic exchange through pollination. To this end, closest to extrafloral nectaries of flowers came to merge with them, joining the structure of their sexual organs. Just emerging floral nectaries are therefore evolutionarily primitive post extrafloral nectaries.

 These small flowers of til or garoe, Ocotea foetens, photographed in the Bosque de los Tiles on the island of Palma, are perfectly orange floral nectaries situated between the stamens and pistil. In this way the plant gets greedy insects that are impregnated with the nectar pollen and bring it to the pistils of other flowers.

 This curious flower plant belongs to the Mediterranean is only pollinated by birds. This is the legume Anagyris foetida, highly toxic and gives off a foul odor by rubbing their leaves by hand. However, the nectar of the floral nectaries located at the bottom of the flower is not toxic and is a candy for the small birds that pollinate it.

Tuesday, June 14, 2011

The avocado, female today, male tomorrow

The Avocado, Persea gratissima or Persea americana, is a Central American fruit tree of the Lauraceae family of grown three races: Mexican, Guatemalan and Antillean, with many natural hybrids between them have led multiple varieties. Mexican cultivars generally resist the cold better than the Guatemalan and Antillean. Under optimum growing avocado tree born of seed can exceed 20 meters, being a wild specimen reaches 30 meters. The grafted samples are much lower, which facilitates the collection of fruit. In recent decades, the cultivation of varieties of Mexican race has spread to many countries with subtropical and Mediterranean climate without frost, especially in coastal areas.

The avocado has hermaphrodite flowers that prevent selfing of a very clever way. The flowers open in two phases well separated in time. In the first phase all flowers of same tree open as female pistil receptive to pollen from other trees, but with undeveloped six stamens to pollen can not fertilize at the same pistil. These details are clearly visible in this and the following images. Recommend expanding the photos with a double click.

Avocado flowers are inconspicuous. Lack petals. The sexual organs are surrounded by six sepals yellow-green to a yarn in each of them. To attract pollinating insects have three orange nectaries situated between the stamens and ovary. With the nectar the bees produce a dark honey with a characteristic taste. In plantations of Malaga, Granada and the Canary Islands produce large amounts of avocado honey protected designation of origin.

In this other flower in female phase is clearly visible all the details. In the center is the swollen ovary of the white pistil leaving just the stigma receiving pollen. Surrounding the ovary are the three nectar of a vivid orange, followed by the six stamens in which extreme are full of pollen anthers still immature.

Finishing the day of the first stage of flowering the female stigma is sealed and the male anthers of the stamens begin to mature, so that at sunrise the next day all flowers of same tree enter the male phase of flowering and anther open for insect pollinators are impregnated with the pollen and bring it to the flower of another avocado that day is in female phase. Thus it is almost impossible for the own pollen fertilizes the stigma, thus avoiding inbreeding would lead to the degeneration of the species perpetuating regressive genes.

Here we see three flowers in male phase with mature stamens that have been stretched and lifted so that the insects gluttonous of the nectar are impregnated with the pollen from the anthers.

In some mysterious way which has not yet been explained all individuals of the same cultivar agree to bloom at the same level on alternate days. In large plantations of avocados grow different cultivars are often intermingled, as if they were planted all of the same cultivar bloom all at the same level and no flowers would be pollinated so they would not give any fruit.

In avocado plantations of a single cultivar, to get to fruition, the agriculturists use the random planting of some individuals born seed edges, ie mongrel hybrid, each of which blooms in a different phase, so that ensure good pollination, and that whatever the stage of flowering of avocado plantation edges will always be several avocados flourish in a different phase, bringing the precious pollen by bees and other insects.

In this type of fruit is well understood the importance of bees as pollinators, without which very few flowers would be pollinated and the fruits would be very rare. Pesticide spraying in full bloom would be catastrophic for the bees and productivity of avocados.

Avocado flower in the male phase. The sepals are bent down to make it exposed the stamens and facilitate impregnation with pollen from insects. In this second phase the three nectaries still produce abundant nectar to attract pollinators to flowers.

Another flower of Persea gratissima in male phase. If the ovary is fertilized with pollen from another avocado in a few days begin to grow larger and change its color from white to green. With the passage of the days its weight will double the long petiole downwards and the fruit will acquire the aspect of a testicle. Just the name of avocado, ahuacatl, comes from the ancient Aztec language Nahuatl and means testicle. The word guacamole, ahuacamolli, also comes from the Nahuatl language and means avocado salsa. During the Inca empire avocado cultivation spread south and in Quechua-speaking Incas gave the name of Palta, which is why in South America they call the fruit Palta and the tree Palto.

And here is the result of this curious flowering in two phases, a beautiful ahuacatl or palta seed always a hybrid, which if planted will result in a massive tree that will take about 12 years to give their first flower and 15 years to produce the first fruits, as during the early flowers tend to fall without reaching fruition.

The fruits may be round or oblong, with green or purple skin, smooth or rough and weight can range from about 50 grams in dwarf avocados without seed to more than one kilogram in some varieties of Puerto Rico.

Monday, June 13, 2011

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".

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.

Saturday, June 11, 2011

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.