Asplenium hemionitis, the design done art

Asplenium hemionitis is for me one of the most beautiful ferns Macaronesia. The design of its fronds and the symmetry of its sori are the result of millions of years of evolution. Belongs to the large family of Aspleniaceae and chromosome is diploid (2n = 72). Its fronds, leathery texture and a bright green color, they blend with the ivy leaves, hence the Portuguese called "Feto de folha de hera." In the Canary Islands called "Hierba candil". Need permanent humidity throughout the year, achieved thanks to the phenomenon of horizontal rain water supplies laurel forests, which are their habitat.

 

Old copy of Asplenium hemionitis on the island of Faial in the Azores Archipelago. On these islands, the humidity is so great that this fern can live in full sun, coming to colonize the walls lining the roads.

Fronds of Asplenium hemionitis, a vivid bright green and leathery texture, and plastic. Are up to 35 cms. with the petiole slightly longer than the blade.

Came to settle in much of Europe and North Africa, coinciding with a period of subtropical climate, warm and moist laurel forests which had its greatest expansion. With the last ice was retreating towards the south and east, fleeing the cold, being held since then in the four archipelagos of Macaronesia, several localities in Portugal where persistent pockets of laurel forest, such as Sierra de Mafra and Sierra de Sintra-Cascais, and some cool, damp locations in northern Africa (Morocco, Algeria and Tunisia).

 

The symmetry of sori seems designed by a mathematician. The one half is the mirror image of the other half. Have a linear structure and are distributed along the veins of the frond. The photo is immature, yet covered by the indusium which is membranaceous, rigid, narrow and wide.

Underside of frond with sori other mature, with the indusium up for the sporangia to disperse the spores. In the photograph you can see a dark dust around the sori which are the spores. You can also see the long black petiole of fronds. (Double click on the photo to enlarge.)

 

Detail of mature sori with raised white indusium. Black sporangia are made spores that are dispersed as small catapults.

 

Sporangium of Asplenium hemionitis, who for some reason could not disperse the spores. Still remain within the transparent bag medium tear, which serves as a womb to maturity.

Asplenium hemionitis tiny spores. The small size indicates its diploid chromosome.

In the town of Taganana on the island of Tenerife was found a beautiful hybrid between Asplenium  onopteris and Asplenium hemionitis called Asplenium x tagananaense.

 

Asplenium x tagananaense looks antediluvian. The long black stalks its fronds are a feature shared by both parents. The blade has an intermediate structure, although its more reminiscent of the parent sori Asplenium hemionitis. These last two photos belong to the great web of photographs of ferns Andrew Leonard. You can see more photos at this link: Andrew Leonard´s fern site  

( 1/2 grandfather + 1/2 grandmother ) + 1 grandmother = Asplenium X sollerense

Yes, indeed, to go crazy. What happens in this family of ferns in the Soller Valley is the height of incest. In the words of the Royal Academy of Spanish Language, incest is the carnal intercourse between relatives within the degrees to which marriage is forbidden. Exactly what they have done the apomeiotic daughter of the grandmother and the apogamic grandson of the grandmother. The fruit of their relationship is a very strong beautiful fern, Asplenium X sollerense, endemic to the Soller Valley on the Island of Mallorca.

Asplenium fontanum ( FF )   >    >    X    <    <    <    <  Asplenium petrarchae ssp. bivalens ( PP )

    v                                               ( Hibridación interespecífica )                         v

    v                                                                    v                                                                       v

    v                                                                    v                                                                       v

    v                                 Asplenium protomajoricum ( FP )                                  v

    v                                                                  v                                   ( Duplicación cromosómica por Apomeiosis )

    v                                                                  v                                                                        v

    v                                     ( Apomeiosis y Apogamia )                                              v 

    v                                                                 v                                                                         v         

    v                                                                 v                                                                         v        

     >  >  >   X  <  <  Asplenium majoricum  ( FFPP ) >  >  X  <  < Asplenium petrarchae ssp. petrarchae ( PPPP )

                    v                                                                                               v

                    v                                                                                               v

      ( Retrohibridación )                                     ( Retrohibridación indirecta )

                    v                                                                                              v

                    v                                                                                              v

 Asplenium x reichsteinii ( FFP )                      Asplenium x sollerense ( FPPP )

This is the complicated family tree of this family that moves from convention, taboos and prohibitions. One would think that its members are envious of the Pharaohs, who married their sisters.

Asplenium x sollerense is thus a hybrid allotetraploid with 75% of the genome from the Asplenium petrarchae ssp. bivalens (its grandmother) and the remaining 25% of Asplenium fontanum (its grandfather).

 

Old copy of Asplenium x sollerense, with its long drooping fronds of a lively light green color in a shady crack oriented northwest to 200 meters. in Can Gomila farm, near the town of Soller.
 

Another Asplenium x sollerense with new long fronds wider at its distal portion and green rachis. This specimen grows facing north about 500 meters.

Younger specimen that grows to about 300 meters in a grove of beautiful old gully of Biniaraix. Lives surrounded by its parents, Asplenium petrarchae ssp. petrarchae that is darker and more hairy and Asplenium majoricum, much smaller and low hairiness. I was much struck by their vivid green, a legacy of its grandfather Asplenium fontanum and the width and the large size of the blade of its fronds.

The pendular disposition and the length of the fronds is an inheritance from its grandfather, Asplenium fontanum. The fronds of the photo are about 15 cm. long, petiole is black and shorter than the lamina, this is lanceolate more thin to the base with green rachis except in its most proximal part; apex slightly elongated and obtuse; alternate, asymetrical and wide pinnae with lobed-crenulate edge, the distal larger with glandular  unicellular hairs.

 

Trichomes or glandular hairs of Asplenium x sollerense formed by a single tubular cell ending in a excretory bulb, where essential stinging oils are excreted as a defense against herbivorous animals. All descendants of Asplenium petrarchae have these trichomes in a greater or lesser number. Glandular hairs of ferns are the evolutionary precursors of the sticky hairs of carnivorous plants, which, besides sticky substances, also excrete digestive enzymes to digest its prey.

Another microscopic image of glandular hairs of Asplenium x sollerense with measures in microns. (Double click on the photo to enlarge.)

Underside of several pinnae with immature sori covered by the indusium, arranged on each side of the central axis of each pinna. Black spine is appreciated in the 2/5 proximal to the underside of the blade. In the 3/5 distal rachis green. In contrast, in the top of the spine predominantly green, dark only in the most proximal.

Spores obtained from the old and vigorous specimen of Can Gomila. We do not see any aborted, it looks normal and rather large as those of all tetraploid. 

As with its cousin Asplenium x reichsteinii, Asplenium x sollerense, although theoretically barren, is also able to generate viable spores and it is not difficult to find copies alone in the walls of more wet darkest terraces of Soller Valley. The most striking is its vivid green colour, the pendular disposition of its long fronds and the form of its blade, conspicuously wider at its distal part.