Thursday, July 19, 2012

Pericartiellus durieui, an Umbilicus rupestris parasite.

Its larva secretes hormones that cause abnormal plant growths called galls.

The beetle Pericartiellus durieui (Lucas, 1846) depends on both the crassulaceae Umbilicus rupestris for playback that if this persists, it would too.

Galls caused by Pericartiellus durieui larvae in the stems of Umbilicus rupestris. (I recommend enlarge photos with a double click).

Its scientific name, as with many animal and plant species, is not without controversy among entomologists. Many of them give it other names: Nanophyes durieui and Nanophyes Lucasi, but it seems that the name internationally accepted as valid is to Pericartiellus durieui. See European Environment Agency.

Several copies of Umbilicus rupestris galls. All images were taken guts in early May in a dry stone wall of the Parc Natural del Carrascar de la Font Roja in Alcoy, Alicante. The exuberance and diversity of the flora of this park is spectacular.

The female beetle, once it has been fertilized by a male, looking Umbilicus rupestris plants healthy and lays its eggs inside the fleshy stems, just below the plant cuticle. Following commissioning in late summer, the adults die. Thus ends the life cycle and start a new one.

Previous galls with details of the inflorescence of Umbilicus rupestris who barely been able to develop, as the parasite larvae secrete hormones that inhibit flowering, to ensure their galls the contribution of substantially all of the water and nutrients up from the roots of the host.

Two plants of Umbilicus rupestris with galls.

Previous galls with details of the inflorescence inhibited by hormones of the parasite.

In this image of Umbilicus rupestris healthy with long inflorescences and stems without galls very well appreciate the differences between parasitized plants. 

Several galls halved to view its contents.

In early fall the eggs hatch inside the stems of Umbilicus rupestris and the larvae begin to secrete hormones that cause an exaggerated and abnormal growth of plant tissues that surround it, as if they were true cancerous tumors called galls. This tumor tissue serves as food for the larvae and also protects it from predation by insectivorous birds and it can withstand the cold long winter.

In the right half of this gall is the head of a larva of Pericartiellus durieui and half left transparent larva after another tumor tissues.

The larvae grow in the fall, winter and spring fed by the moist tissues of the barb, digging in her galleries as they feed. In early summer the larva undergoes a metamorphosis and becomes a nymph.

 Above larva with an arrow.

In the upper right half of this gall can see a small white larva.

Previous larva about 3 millimeters long and 1 mm thick with brown head and white body.

During the first weeks of summer, the pupa is gradually metamorphosing their internal organs and in September becomes an adult beetle, a tiny coleopter a few millimeters, which opens an outlet in the gall cuticle and emerge outside. Then the female emits sexual pheromones to attract males flying towards her, copulate and fertilize their eggs. After copulation the males die and the mated female flies in search of healthy Umbilicus rupestris to lay their eggs, after which she dies. And again begins the peculiar life cycle.

Pericartiellus durieui adult insect. This image is owned by the magnificent website:

Sunday, July 8, 2012

Lysimachia minoricensis, its destination was the extinction

All attempts to reintroduce it in the wild have failed.

Extinction in the nature of Lysimachia minoricensis remains a mystery. All the hypothesis are logic, but they are still assumptions, because none has been established. 

Lysimachia minoricensis in April. This plant is a biennial cycle. During the first year develop numerous leaves and branches, in the second spring bloom well into summer, in August mature seeds and in autumn and winter dispersed the seeds, after which it withers and dies.

One of these assumptions attribute their extinction to the collection by botanists over a century ago, they had the nefarious habit of collecting every one of them a complete personal herbarium. The discovery of a single, small population of this Primulaceae in 1879 by the renowned Menorcan botanist Joan J. Rodriguez i Femenias (1839-1905) in the Barranc de Sa Vall, located on the south coast of Menorca, mobilized many botanists of the time excited by the discovery of this rare endemic and eager to have their own specimen in their collection of dried plants.

Another theory blames a forest fire occurred between 1926 and 1950 that could wipe out all the vegetation of the gorge where the only known population grew.

Lysimachia minoricensis leaves.

A third hypothesis assumes that agriculture and livestock by man since ancient times favored the survival of  Lysimachia keeping "clean" of vegetation its habitat, it seems that does not tolerate competition from other plants nearby. The progressive abandonment of the field grew the weeds choking the Lysimachia. In fact, with different cultivation in botanic gardens have been found to need bright open spaces. However its discoverer wrote that grew in a cool and shady. Cattle grazing does not affect it because the unpleasant odor of its leaves protect it from being devoured. The odor seems to be an adaptation to the browsing of the extinct antelope Myotragus balearicus who lived in Menorca until about 4,000 years. It was responsible for maintaining clear their habitat by feeding on plants that could compete with it. With the arrival of man on the island Myotragus became extinct in a few decades, probably by over-hunting and was replaced by goats, sheep and cows.

 Detail of a sheet beam with beautiful whitish veins standing out against the dark green lamina.

Lower leaf surface above maroon for its rich in anthocyanins. The bottom of purple color shows that the botanist Joan J. Femenías Rodriguez was right in saying that the only copies who he had found living in a dark habitat. The concentration of anthocyanins in the underside of the leaves is intended to maximize the little light reaching plants living in understory and in north-facing rocky habitats. When solar rays fall on the leaves, penetrate their green tissues where the organelles called chloroplasts capture the light energy and conduct the photosynthesis of the nutrients that plant needs. In normal leaves the solar rays, that are not captured by chloroplasts, cross the leaves and they are lost. However, in the leaves of Lysimachia minoricensis these rays that are going to lose found the layer of cells rich in purple anthocyanins on the underside and are reflected as if it were a mirror, so go back to the green tissues of the leaf and chloroplasts the advantage to perform a second photosynthesis. It is an intelligent process of optimization.

Leaf of Lysimachia minoricensis view backlight. Particularly striking is the highest concentration of anthocyanins in the midrib and in secondary veins. These purple  ribs correspond with the white spots of beam of leaves.

The timely collection of Lysimachia minoricensis seeds in 1926 by the renowned Lleida botanist Pius Font i Quer (1888-1964) and later planted in the Botanical Garden of Barcelona prevented disappear forever from the face of the Earth. Its cultivation in Barcelona was a huge success with abundant germination and survival of many plants that bloom and fructified smoothly year after year. During the Spanish Civil War and early postwar years the garden was abandoned to their fate. When political conditions allowed to resume the care of the garden is believed completely extinguished, but miraculously weeding a small population was found under some bushes. The joy of botanists to test their survival were encouraged to send the highest seed to other botanic gardens, so it could not be any more in danger of extinction. Now grown successfully in many Spanish botanical gardens as the Soller Botanical Garden in Mallorca and foreigners such as Brest, Budapest, Coimbra and Copenhagen. Is also known to survive without problems in some private gardens.

Lysimachia minoricensis flowers in May.

Is assumed to be extinct in the wild between 1926, date of seed collection by Pius Font i Quer and 1950, the resumption of visits by botanists to Barranc de Sa Vall after parentheses the Civil War. After nine years looking for it, in 1959 the botanists Pedro Montserrat, Antoni de Bolos and his son Oriol de Bolos found its disappearance in the only known and declared extinct in the wild.

Detail of the flowers that need not to be pollinated to produce viable seeds.

Since it was declared extinct have been many attempts to reintroduce into the wild. There have been all sorts of experiments, some with surprising results. The first attempt was to disperse thousands of seeds in the Barranc de Sa Vall and other nearby ravines with cool, moist habitats supposedly adequate, as the Algendar and Trebaluger with abundant germination and seedling survival until the summer, when they died all watering yet, except for two sites with fresh, loose and deep soil of Barranc d'Algendar, where some plants were able to overcome the first summer and the following year flowered and gave abundant seeds. Encouraged by the success they proceeded to plant these seeds that germinated well, but only in one locality have overcome the first year.

In late June, Lysimachia minoricensis already formed fruit, though still immature. In the image are several mature plants with long infructescences and many young plants that will bloom next spring.

Immature fruits of Lysimachia minoricensis in early summer.

In 1996 an experiment was done with the planting of mycorrhizal adult plants, which established well and grew vigorously, reaching flowering and fruiting in the first year after planting. Its seeds, however, in low numbers and germinated seedlings did not survive the first summer despite watered regularly.

Details of the fruit in the form of capsules containing numerous black seeds 1 mm. A single plant can produce up to 3,300 seeds, with an average of 1,100.

Given the poor results of all attempts at reintroduction into the southern cliffs of the island with calcareous earth which was supposed to be wild, it was decided to plant mature plants grown in pots, from seeds obtained from plants that had been fruitful in previous experiments, in the interior of the island with siliceous earth, theoretically more cool and moist. Plants grew very vigorous with larger leaves, inflorescences long and numerous flowers, no problems beating the summer. However, despite the abundant production of viable seeds, has not yet been found no germination.

In January the fruits of Lysimachia minoricensis already open and scattered the seeds.

 In this picture we can see the fruits open and empty. At the apex of each capsule is between five seven dehiscent teeth, which are separated to allow dispersion of the seeds.

Is Lysimachia minoricensis condemned to live forever in botanical gardens?

Will ever survive and reproduce without problems in nature without man's help?

Was it the small number of individuals which led to the extinction to be diminishing their genetic variability?. And if so, why is shown as beautiful, healthy and vigorous when grown in gardens and dies or does not play when it is reintroduced into the wild?. Why in the Soller Botanical Garden, located on the neighboring island of Mallorca, the Lysimachia minoricensis is so comfortable that behaves almost like a plague with thousands of plants that are born alone and become adults without problems? 

Will the botanical understand someday capricious behavior of this plant seems to hate its island home and instead lives happily in habitats as different which is supposed to be adapted such as the botanical gardens of Brest (France),  Budapest (Hungary) , Coimbra (Portugal) and Copenhagen (Denmark)?

Sunday, July 1, 2012

Dicksonia antarctica, a fern of The Tertiary

Dicksonia antarctica tree fern is native from the Australian states of New South Wales, Tasmania and Victoria. One of the most widely cultivated tree fern by gardeners around the world. Grows seamlessly into any type of soil, both acid and calcareous, provided with a good drainage, a substrate rich in well-decomposed organic matter and a constant supply of moisture in the soil and in the air. It lives well in shade or partial shade of trees, as in the wild is a fern understory. It originated in the tropical forests of the Tertiary with a warm and permanently moist.

Dicksonia antarctica new frond in early May. This and the following photographs were taken in the magnificent botanical garden called the Huerto del cura, part of the immense palm grove of Elche, located in the province of Alicante. All new fronds of ferns as they display  take this spiral form that follows the Fibonacci mathematical sequence. (I recommend enlarge photos with a double click)

Dicksonia antarctica about 25 years in the shadow of the beautiful palm trees from around the world that form the collection of this botanical garden. On arriving, is a small oasis of tranquility amid the bustle of the city of Elche. It live in complete harmony hundreds of species of palms, Strelitzia, cycads, zamias and cactus.

 Dicksonia antarctica trunk is actually a rhizome along with the dried remains of the petioles of old fronds. The 90 inches of the trunk give us an approximate age of 25 years, as this fern grows very slowly between 3'5 and 5 centimeters per year, somewhat faster in the wild where it can easily reach 15 -20 meters height.

Dicksonia antarctica crown with sprouting new fronds spring.

 Another Dicksonia antarctica slightly younger than the previous one with a trunk about 50 inches.

Fern crown before. The fronds may be sterile or fertile and are springing alternately at different times of year.

The fronds have a very short petiole and an ovate-lanceolate tripinnate blade formed by narrow and lanceolate pinnae.

 Dicksonia antarctica pinnae are also subdivided into lanceolate pinnules, inserted obliquely on the rachis of the pinna with a very short petiole.

 The pinnules are subdivided into their small sessile lobes, ie without petiole, finished in a very fine tip oriented toward the apex of the pinna.

 Underside of a pinna with mature sori covered by a bilobed indusium which are situated on the edge of the lobes of pinnulae.

Same seen from above sori nearer. The indusium is up leaving mature sporangia hovering about to unfold and disperse the spores.

Details of the sori of Dicksonia antarctica.

Already deployed and empty sporangium after dispersion of spores. It is very striking is the large number of cells in the ring.

 Spores of Dicksonia antarctica with a nice golden brown and measures quite large.