Tuesday, January 4, 2011

Dryopteris pallida ssp. balearica, endemic to Mallorca

Spanish territory is home to three endemic Dryopteris: the Asturian male fern, Dryopteris corleyi, endemic in Asturias and Cantabria, the canary male fern, Dryopteris oligodonta, endemic to most western Canary Islands and finally the Dryopteris pallida ssp. balearica, Majorcan sister of Dryopteris pallida ssp. palllida, who lives in the western Mediterranean.

Group Dryopteris pallida ssp. balearica in a limestone crevice very shady and cool towards the north a few meters from the sea. It shares its habitat with other Balearic endemic, the Sibthorpia africana, a Scrophulariaceae that grows like a carpet of small rounded leaves covered with hairs. Photograph taken in March at the Puig Fumat of the Formentor peninsula. (Double click on the photo to enlarge)

Sibthorpia africana hairy leaves. Live in shady, damp, cool oriented to the north.
Same group of Dryopteris pallida ssp. balearica one year later in July. It is very curious tendency of the apex of the fronds to lean to one side. Particularly striking is the absence of African Sibthorpia, whose stems are dry in summer, is sprouting again with the first rains of autumn.

Solitary specimen growing in a quarry in the Pla de Cuber of the Serra de Tramuntana. A year later it had disappeared by predation by feral goats, which have become a very destructive pest for the endemics to Mallorca. Control until bearable limits is blocked by hunting interests, which move large sums of money.

Small Dryopteris pallida ssp. balearica growing between the stones of a wall patch in the gully of Biniaraix. Its small size is due to continuous grazing of goats and sheep, which every year eat their fronds are most at risk, weakening it and forcing it to sprout in summer when the rains stop and the substrate on which grows completely dried for four long months.

Typical frond of Dryopteris pallida ssp. balearica of no more than 25 cm in length, with the petiole at or above the blade, which has a clearly triangular deltoid and a vivid green color.

Sori ripe with typical kidney-shaped form, typical of the genus Dryopteris ferns. Photo taken in July in full dispersion of the spores. (Double click on the photo to enlarge)

Detail of mature sori with reniform indusium lifted, exposing the sporangia as brown balls about to be deployed to disperse the spores.

Beautiful sporangium of Dryopteris pallida ssp. balearica ring cells with red and yellow and transparent bag torn and empty after the dispersal of spores.

Finally the spores with perispore and beautiful brown-earth, photographed very cool and well hydrated. Once dispersed they dehydrate partially and decrease slightly in size. If planted in a suitable medium, they germinate easily.

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