Oliver Gluch's World of Carnivorous Plants

Typical flowers of P. crystallina ssp. hirtiflora showing a rose-white to pale bluish-white pattern of the corolla. The corolla can reach up to 2 cm in diameter. The lobes of the lower lips mostly are shallowly notched. The calyx has light green spathulate leaves, which is according to J. Casper a unique feature within the European-Asian butterwort species. The tube is showing a conic form and is of a yellow-green colour. Also typical for this species are the elliptic to obovate leaves having a insertion at their tip. The flower has a prominent palate at the basal portion on the lower middle lip, consisting of several rows of yellow hair.

P. crystallina ssp. crystallina has smaller flowers (this feature is also visible when ssp. crystallina and ssp. hirtiflora populations are cultivated under the same conditions). The colour of the flower varies between whitish, pale rose and bluish. In comparison to the ssp. hirtiflora-populations growing in Italy and in the Balkans the size of the plants are also smaller and the two-lipped flower form is more obvious. The lobes of the lower lips are generally not notched. Other differences to ssp. hirtiflora are the more brownish coloration of the top of the tube as well as the more prominent brown stripe on the interior surface of the tube.

All populations of P. crystallina do not hibernacle in winter. Therefore the species is homophyllous. It has been observed that in winter, especially when temperatures are around the freezing point, the rosette can be much smaller than under warmer conditions. The habitat for this species can vary a lot. Populations are mainly found on vertical limestome cliffs, but also on serpentine. Other populations grow on calcerous wet meadows along small rivers or in sphagnum bogs. A quite extraordinary habitat of P. crystallina ssp. hirtiflora is that of Salerno (Italy), where the plants grow on wet tuffa rocks at sea level, sometimes getting sprayed over by sea water.

Cultivation of this species is not such easy. I have good experience in cultivating them in mini-greenhouses inside under artificial light, where humidity is quite high. As substrate I use a mix of calcerous soil and fine quartz sand to prevent the appearance of fungi due to high humidity. The greenhouses are heated during day at about 24° C, while during night temperatures fall to 12° C. In winter night temperatures are even lower, because I keep the plants in a non-heated room.

I kept the plants also outside during winter. Although this species does not form a hibernaculum, most of the plants survived temperatures of about -15° C (some sites of P. crystallina ssp. hirtiflora are located up to 1600 m above sea level). But I recommend to protect the plants against severe frost.

Until 1991 P. crystallina and P. hirtiflora were considered as two distinct species, but after the re-evalution of the species by A. Strid P. hirtiflora now is not a distinct species anymore but a subspecies of P. crystallina. According to Strid the populations are to closely related as to be considered as two different species.

P. crystallina ssp. crystallina was considered endemic to the Troodos Mountains on Cyprus, but in 1966 there are records from J. Casper that there are also populations on the Turkish mainland (Anatolia). P. crystallina ssp. hirtiflora is a more widespread species. The distribution of this species reaches from the westernmost point in Italy (populations near Salerno and in the Abruzzian Mountains) to Albania, Bosnia-Herzegowina down to Greece.