Sunday, April 22, 2012

Ophrys balearica, proud to be black

The beautiful Ophrys balearica is the unique orchid endemic to the Balearic Islands. Belongs to the Ophrys bertolonii group and it is cousin of Ophrys catalaunica. The blackness and width of its velvety labellum, the metalised brightness of their garnet macula and its gynostem as a small head of a bird are several of its most striking features.

Ophrys balearica flower in early April. This specimen grows in the Serra de Tramuntana in the skirt of a mountain facing the northwest. I recommend enlarge photos with a double click to appreciate its beauty.

As with all orchids, the flowers lack nectar and attract their pollinators with two strategies of imitation or deceit: a structural that mimics the shape and colors of a receptive female and a chemical through the emission of sex pheromones virtually identical to the female insect. Each orchid has a specific pollinator, but this may have several. There are also specialized pollinators in the genus Ophrys that mate indiscriminately with different species of the genus, leading quite often to beautiful interspecific hybrids. The pollinator is always a male. 

Orchids through millions of years of evolution, after testing several experimental mutations have been so perfectly mimic the females of hymenopteran pollinators, bees and bumblebees in general, that males are attracted to their flowers with an irresistible form and copulate with them as if it were true females. In doing so, in the frenzy of copulation, both pollinia loaded with pollen adhere to the head or abdomen of the insect. After copulation the male just flies in search of another female, which logically expected to be true, but for the way it meets the irresistible scent of another false female pheromones and falls back into deception. Coupled with the second false female and in the frenzy of copulation carrying pollinia glued from the first flower pasted into the stigmatic cavity of the gynostem and the second false female is fertilized. Deception has been a success and the orchid has already secured the next generation.

Ophrys balearica initiating flowering in early April. They look good basal leaves and cauline leaf on the stem.

Basal leaves of the previous Ophrys balearica.

 Floral bud opening in early April.

In spring it rains very little in the Balearic Islands. Every four or five years there is a terrible drought. Let the rain in late January and will no longer drop a minimally acceptable rain until late September or early October. Under these extreme conditions the Ophrys balearica has only accumulated reserves in their tiny tuber and flower must absorb water and nutrients from its leaves. The picture shows a specimen without leaves in late April. The tuber has absorbed the entire contents of the leaves and flowers sent to making a titanic effort to get produce seeds, thus ensuring the next generation. 

 To test further the poor orchid the lack of rain prevents grass outbreak, rabbits and hares find nothing to eat and then feed on small basal leaves of orchids, just at the moment in which the stem flower should start to grow. If the drought persists, the whole effort of our beautiful Balearic orchid is useless and rabbits also eat the flowers. It loses a generation of future Ophrys balearica. Underground tuber is unfortunate that dries and disappears. 

 Hopefully sometimes not all is lost, the orchid uses the last of their resources to survive and the old tuber before drying produces one or two tiny tubercles around, that will flower in two years. 

 But do not stop there the calamities of our Ophrys balearica, because sometimes even their tubers are victims of predation by rats and rabbits that they sniff the ground and when they smell the tubers, dig, break through and eat them, undermining of definitely all the titanic effort of the most beautiful orchid in the Balearic Islands.

To further test their ability to survive all orchids of the Balearic Islands have to bear predation on sheep and in recent decades the infernal plague of feral goats that if they find grass and tender shoots of their favorite plants, they feed on the basal leaves and flower stalks of orchids, preventing flower and produce seed the next generation. 

 On farms subject to intensive grazing of sheep is very difficult to find orchids. They are then held in the scrubland and pine forests where sheep graze rarely, preferring to feed on the sparse grass that grows in the open with little tree and shrub vegetation. Goats, by contrast, prefer to browse the tender shoots of shrubs of garrigue and insatiable greed does not respect the young flower stalks of orchids, dramatically accelerating the phasing out of these beautiful plants, especially in mountainous areas of Mallorca.

 In fairness it must be said that most orchid genera Ophrys, Orchis, Anacamptis, Serapias and Himantoglossum they favor a light browsing and grazing to maintain open clear of the garrigue and pine forests, as these plants are eager to sunlight The flowers need to be visible in the eyes of their pollinators. No ultraviolet rays shining on the flowers they are not able to see them, should be directed only by the scent of pheromones emitted from the flower and pollination often does not occur and the ovaries of the flowers are vacuous and dried without producing seeds . Thus, moderate grazing from late spring to early fall not only hurts them but encourages the entry of sunlight and the subsequent production of seeds of the next generation to perpetuate the species.

Although no rain in the cool spring morning dew moisture covers the flowers of Ophrys balearica and helps it to support the extreme drought of our islands.

I remember the excitement I felt several years ago, while photographing the newly opened flowers of Ophrys balearica in a sunny scrubland northwest coast of Majorca, when suddenly a loud black bumblebee, as black as the labellum of the orchid, attracted by the irresistible aroma of false pheromones and pounced on a flower copulating with it in a frenzy. Knowing the great documentary value of a photo of the bumblebee pollinator copulating with the flower of Ophrys balearica, I made few pictures I could in the few seconds that lasted that frenzy, without realizing that was not my digital camera in macro mode. Once back home, I passed pictures to the computer and my disgust was tremendous to see that all had gone blurry and unfocused.

With so refreshing morning swim this flower seems to expect a visit from its eager lover black pollinator.

Picture of an Ophrys balearica flower with details of their anatomy. The strategy of deception is so perfect that the flower has a small yellow appendix at the end of the labellum, called apiculum, which helps the wasp is facing in the intercourse, that is, it know where is the end of the abdomen the false female with the opening for the copulatory organ. The flower has also developed two false ocelli of female, one on each side of the stigmatic cavity. In this way makes the male orchid adopt the correct posture and enter its head with the pollinia attached to it in the stigmatic cavity of the gynostem where are the female organs pollen receptors.

Ophrys balearica fruits in the form of erect and oblong capsules with numerous tiny seeds inside that are dispersed by the wind and the rainwater.

As with all orchids, the seeds to germinate, for lack of nutrient reserves, must find a symbiotic fungus that feeds the seedling in the early stages of germination. They are just a germ cell, a fertilized egg surrounded by a thin sheath cells that protect it. If the seed gets lucky and falls near a freshly germinated spores of specific mycorrhizal fungi, the filaments of the mycelium detected it, like a spider web around her in an embrace of mutual cooperation and stimulate germination by secreting a hormone that raises the cell germ of its lethargy. In the absence of nutritional reserves, the embryo of the orchid in the early cell divisions must receive the nutrients provided by the filaments of the mycelium. Only then can continue the process of germination. When the orchid seedling take their first roots, it form an intimate union with the mycelium, a mutualistic symbiosis, a marriage of convenience that will last the life of the orchid. The filaments of the fungi provide water and minerals to the roots and they will return the favor supply carbohydrates synthesized by the chloroplasts of leaf photosynthesis.

Saturday, April 14, 2012

Anagallis arvensis, Fashion Show

Anagallis arvensis is an annual cycle herb of Primulaceae family relatively abundant in fields, roads, clearings of garrigue and pine forests, roadsides, edges of gardens and parks and coastal areas. Approximately 70% of plants produce flowers in dark blue and the remaining 30% red-orange flowers. However it is not difficult to find any hybrid or mutant copy with flowers of other colors: white, pink, blue, fuschia ....

Combined image with flowers of four colors. I recommend enlarge the photos with a double click.

The blue-flowered Anagallis arvensis is the most common.

The flowers of an intense dark blue stand out much on the light green of the leaves.

Each flower has five blue petals with striations like little fans. At the center acquired a nice color fuchsia. The five stamens protrude several millimeters above the flower and finish in a striking yellow anthers.

The variety of orange-red flowers are less abundant.

As in the blue flowers, in the red-orange variety the petals also become fuchsias in the center of the flower. We can see very well the five yellow anthers of the stamens.

.It is not difficult to find the two varieties growing together. Sometimes they are so intermingled that seem a single plant with flowers of two colors. However, if we follow each shoot to the roots, we see that they are different plants.

Find a copy of albino flowers is a surprise, a fluke.

The petals are white with a slight pink tinge and in the center of the flower show a deep blue ocean. The image clearly distinguishes the long-fuchsia red pistil protruding slightly above the five yellow anthers of the stamens.

 This Anagallis arvensis had flowers of different tonalities of sky blue color, some almost white. In the center had a striking fuchsia color.

In this picture we can see an albino flower with center of pink color much clearer than the previous flower. The blue flower belonged to another plant.

There is also a variety of flowers of an intense pink with red center.

Another pink flower in which we can see all the details. The flowers of Anagallis arvensis grown on a pedicel whose length ranges between 8 and 45 millimeters longer than the axilar leave of which they arise. In the picture, behind the petals, we can appreciate the five lanceolate-acuminate teeth of the calyx that is deeply divided.

And finally the variety of fuchsia flowers, most beautiful and strange. I would say that is a hybrid variety intermediate between the marine blue and the orange-red varieties.

The stems of this plant can grow to 70 centimeters. The leaves are opposite, sessile, ovate-oblong, sometimes lanceolate. On the underside often have blackish brown spots. The image shows fine details of the pedicels of flowers emerging from the armpit or junction of each leaf with the stem.

The fuchsia-colored flowers are for me the most beautiful. The petals have a tone somewhere between the two most abundant and the center of the flower becomes an intense blood-red.

Friday, April 6, 2012

Daphne rodriguezii: the art of camouflage

 It plays the hiding place with the wind of Menorca

This exclusive endemism of the Island of Menorca and the near Island d´en Colom is a true artist of the cripsis or camouflage. Its small size, its discreet and little compact foliage, its flowers of a white color extinguished or cream that merge perfectly with the sandy ground on which it lives and their preference to grow under other shrubs with which it intermingles their branches make it happen unnoticed completely. All botanists who have studied it are agree on how easy is to go near it ​​and see not it.
Flowers of Daphne rodriguezii at the beginning of April. I recommend to extend the photos with a double click to appreciate better the details. 

Floral cocoons of Daphne rodriguezii that keep extraordinary a similar one with those from the jasmin.

This Minorcan endemism grows in coastal maquis of the very windy coasts, coverall those of the East of the island. The form of the leaves and its tendency to grow almost level with the ground under other shrubs, coverall Pistacia lentiscus and Phyllirea latifolia var. rodriguezii, with their branches intermingled with those of these, protects it of the strong winds that usually whip the North and East of Menorca. It lives between the 5 and the 80 msnm.

The flowers of this small shrub of the Thymelaeaceae family can be white or cream color. In the image a unit with abundant flowers of cream color can be seen. 

The delicate and discreet color of the flowers allows it to camouflage perfectly with the siliceous sand ground of the coastal zones of Menorca and the Island d´en Colom. This small island of only 59 hectares is included in the Natural Park of s´Albufera des Grau. It is separated of the northeastern coast of Menorca by about 200 meters of sea with an immaculate water of a gorgeous turkish blue color and in it lives the most important population on Daphne rodriguezii. (To see the plane of  Parque Natural de s´Alburera des Grau)

This shrub rarely surpasses the 50 centimeters of height. Their branches are short and intricate, new with appressed hairs and old glabrous. The crust is grayish.

The other variety has the flowers of a white color extinguished that do not call anything the attention when happening next to the shrub. 

 The flowers are very small. They have the sepals and petals united forming a tube called hypanthium that usually has purple dyes and measures between 7 and 11 millimeters in length. The 4 sepals open in the end of the flower and they do not surpass the 4 millimeters.

Sprouting spring to early April.

This Minorcan endemism is catalogued like very vulnerable and in serious danger of extinction for being very sensible to the alteration of its habitat. It is including in the Red List of the Spanish Vascular Flora, in the Directive Habitat and the Agreement of Berna.

The leaves of new buds are suborbicular or obovate; the others are obovate or elliptical with the apex cleared and attenuated in the base. All are persistent, coriaceous, of dark green color and shining by the beam and paler by underside, with the margin revolute and provided of short hairs of 0´2 millimeters. 

Red-orange, fleshy and globose fruits of Daphne rodriguezii, including in the hypanthium until reaching the maturity. Usually they measure about 5 millimeters. They mature at the beginning of the summer. The fruits are eaten by the lizard Podarcis lilfordi, which then disperse the seeds with their droppings.

This endemism was found by the prestigious Minorcan botanist Joan Rodriguez Femenias in 1866. For its correct classification he sent samples to a botanical friend, Joan Teixidor Cos, who with very little ethics published it as an own discovery two years later in 1868. Despite it is necessary to say to his favor that had the detail to dedicate the new plant to his Rodriguez friend, giving it his name to the species, Daphne rodriguezii. Dr. Joan Rodriguez Femenías, very victim, a year later tried to register the plant with a new name, Daphne vellaeoides, but the international norms of nomenclature of species give priority to the first registered name and the name that he put it has stayed as synonymous.

Sunday, April 1, 2012

Euphorbia margalidiana: it lives alone in an islet

The greater islet of Ses Margalides, located closely together of the coast the northwest of the Island of Ibiza, lodges a unique botanical treasure, the Euphorbia margalidiana, an extraordinary plant that was isolated on the islet after raising the level of the Mediterranean Sea million years ago and evolved undergoing diverse mutations to adapt to an extremely dry rocky habitat, whipped by strong winds, with a very little and salty substrate by the continue splashes of the marine water and an intense insolation without the protection of the minimum shade.

 Euphorbia margalidiana inflorescence at the end of March. I recommend to extend the photos with a double click to appreciate better the details.

Both islets of Ses Margalides. The little vegetation that can be seen on the greater islet is formed almost exclusively by about 200 adult units of Euphorbia margalidiana of until a meter of height. In the smaller islet any unit of this endemism does not live.

Islets of Ses Margalides closely together of the coast of Ibiza.

The arrow indicates the exact situation of Ses Margalides.

The Islets of Ses Margalides are located in the Western Mediterranean. About 6 million years ago, during the Messinian Period, the Mediterranean Basin was dried almost completely and what now they are two Islets surrounded by the water were then two great rocks integrated in the top of a mountain that comprised of the Betic-Rif Massif. After changing the climate and open the Straits of Gibraltar, the Mediterranean Sea filled again of water and what they were mountains became islands and islets, being isolated the ancestor of Euphorbia margalidiana of its congeners of Ibiza, that belonged surely to Euphorbia squamigera species. The isolation in so adverse conditions forcet it to adapt not to be extinguished.

All the photos that I show you belong to units worked in the magnificent Soller Botanical Garden, located in the Island of Majorca, because the access to Islets of Ses Margalides is prohibited by the law. In the image a vigorous unit of about 80 centimeters of height is seen initiating the spring flowering.

The leaves of Euphorbia margalidiana are great of up to 7 x2´5 centimeters, glaucous with a clearly green color slightly bluish, lanceolate, with the pointed apex, of whole margin and without no hairiness, that is to say, glabrous.

In order to adapt to the conditions of extreme drought of the islet the Euphorbia margalidiana underwent diverse mutations transforming its ligneous stem into suculent one accumulating in it the rainwater, since the cactus and the succulent plants do, to be able to support to the length, torrid and parched summer of Ibiza. In the image we see the succulent stem and the detail of the white line of raquis of the leaves. The tiny white small points are grain of pine pollen.

Underside of a leaf of a green color more clearly than the anverse.

The flowering begins at the end of March. The nectar produced by the five nectaries of the flowers likes much to the ants that are its pollenizers in the islet.

 Another pollenizer ant feeding on the rich nectar of a just opened flower.

Euphorbia margalidiana inflorescence. In the image we can see a small insect without wings, that I suspect that it could be a predator of ants.

Another inflorescence.

Image in detail with all the components of one of the five divisions that form the inflorescence. The five nectaries surround five masculine flowers without petals each by them reduced to simple stamen, who surround a unique feminine flower that it open in the end of a very heavy length pedicel and is trained by a trilocular ovary and in the end three feminine styles.

In the end of the feminine flower of the left we can see the three styles partially welded by their base and the warty surface of the trilocular o tricarpelar ovary which at maturity will result in a fruit with three compartments full of ellipsoid, smooth, compressed, dark gray or black seeds.

Euphorbia margalidiana is in serious danger of extinction by the reduced number of unit in the nature and the small area where it grows that it is reduced to the top of the greater islet of eight hectares. In order to avoid its extinction it is cultivated successfully in several botanical gardens as the Soller Botanical Garden and the Mar i Murtra Botanical Garden and conserve seeds in their Genebanks. It is protected by autonomic, national and international laws.