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Pinguicula jackii Barnhart (1930)

In 1928 the American naturalist John George Jack discovered during one of his botanical travels in Cuba a Pinguicula population in the Escambray Mountains within the province of Santa Clara, that was still unknown at that time and took some herbarium specimen with him. In 1930 the American botanist John Hendley Barnhart described those specimen as a new species and named it after the discoverer as Pinguicula jackii

This secies is endemic to Cuba and is currently only known from very few places in the Escambray mountains. P. jackii grows on shady, permanent wet calcareous cliffs at elevations between 600 and 800 m. The local climate is characterized by a permanent high humidity and by warm day temperatures and cool nights.

P. jackii is probably a perennial species of tropical-homophyllous growth type. The plants therefore do form only one set of leaves all year round. The rosette consists of 5 to 12 leaves, obovate-rotundate to narrow-cuneate, green to light yellow-green in colour. The leaves are 3,5 to 5 cm long (there were also specimen found that had a leaf length of 10 cm) and 2,5 to 3 cm at its widest point, sometimes even 4 cm. The upper surface of the leaf is densely covered with sessile and stipitate glandular hairs and the margin is involute for two third of the leaf.

P. jackii flowers probably all year round, but currently only the flowering period between July and Mai is documented. Per flowering season up to 6 flowers can be formed, which are borne singly on a flower scape that can get between 7 and 12 cm in length. The scape is of a light green colour and is densely covered with stipitate glandular hairs. Typical for the species is the blue or blue-violet colour of the corolla lobes that fade irregularly to white towards the entrance of the corolla tube. The corolla is bilabiate, but the lobes do not differ much in size and form. Corolla lobes have an oblong to obovate shape. Lobes of the upper lip are up to 1,5 cm and up to 1 cm wide, while the lobes of the lower lip can get up to 1,5 cm in length and are up to 1,3 cm wide. The corolla tube is white with purple parallel running veins, has a broad entrance and a campanulate form. The tube is between 7 to 11 mm long and and between 11 and 13 mm at the widest point. The spur is sub-cylindrical with an obtuse tip, the colour is white to pale green, up to 7 mm long and is sporadically covered with stipitate glandular hairs.

Until date there is not much knowledge available about long term cultivation requirements of P. jackii, as this species is very rare in cultivation. Due to the wet growing conditions combined with high humidity in habitat, it is preferable to cultivate the plants under wet and humid conditions all year round. Roots seem to be quite susceptible to fungus infection, therefore the roots should be controlled on a regular base to check if they still have their white colour. If any brown root tissue is visible, it should be removed immediately. Beside higher air humidity plants of P. jackii do show a better growth when night temperatures drop significantly. It should be avoided to cultivate plants with temperatures higher than 30 C. In addition plants should be grown under more shady conditions. As the species doesn't seem to be self-pollinating (the flower morphology indicates more that flowers are pollinated by insects), seed can only be obtained by hand pollination.