( 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.