- Sat Oct 07, 2017 7:20 pm
I guess I'll offer up my personal preferred way of organizing the different climate groups of the genus.
Cold-temperate: Hibernacula-forming pings and the two temperate South American species, P. chilensis and P. antarctica
While exact temperature tolerances and requirements may vary between some species, these Pings generally do not like hot temps during the growing season, and can easily handle freezing temperatures during the winter. All of these Pinguicula require their dormancy.
European warm-temperate: The Pinguicula from section Cardiophyllum, such as hirtiflora, megaspilaea, etc.
These Pings don't like hot summer temps (though I believe they can handle hot air temps if the water remains cold, sort of like how people used to want to treat Darlingtonia). They won't handle freezing temps like the true cold-temperates, but should be able to handle some frost. As far as I know, these need winter dormancy.
SE US warm-temperates: planifolia, primuliflora, lutea, etc.
Unlike the European warm-temperates, these will tolerate very hot summer temps, even if the water is hot (the exception is primuliflora, which prefers shaded areas that do not get as hot). They also can handle some frost. These do need a winter dormancy to survive long-term, except the plantlets produced by primuliflora will not be affected by any lack of a winter period. That is why you see primuliflora everyone but not any of the other species.
To be honest, I don't know the max temps these can handle during the summer, since I grow mine indoors under T5HOs where the hottest it gets is the low 80s during the day. I know some people let their Mexican Pinguicula get very cold during the winter, near freezing even. Of course, this is not necessary. Their "dormancy" is not necessary for their health (I prefer the term "winter phase" since it is not a true dormancy, excpet for the bulb-forming species), although I am curious to if the bulb-forming ping's winter phase is necessary for healthy long-term growth.
Cuban + P. casabitoana (from the Dominican Republic)
These are the only Pinguicula I would feel comfortable using the term "tropical" with. It is hard to say what applies for all the Cuban species, since only 4 have been in cultivation, but for these four one can generalize. Basically, they like lowland conditions. Warm to hot temps during the day (really lowland ones like filifolia prefer hot, into the 90s), and high humidity. The are generally annuals, with varying degrees of success with self-pollination, so for maintaining the plants in one's collection for the long-term, one must cross plants of different genetics. P. cubensis seems to last a couple years and can be propagated via leaf-pullings. That one also doesn't mind colder temps nor humidity below 70%, but it will grow slower under those conditions.
Equatorial-Andean: P. calyptrata, involuta, chuquisacensis (jarmilae)
It is hard to categorize these Pings since not much is known about their growth requirements, since not too many grow them. Some have grown chuquisacensis (I am not actually sure if it is specifically on the Andes), which seems to do fine in typical highland to intermediate temps. Though it seems to be very humid where it grows naturally, it doesn't need high humidity. Fernando reported hearing from the locals who live near a population of P. calyptrata, that it can snow during the wet season. This plant would probably prefer year-round cool days and cold nights, being one of the highest growing Pings (4000m!). P. involuta, my guess, would be treated as an intermediate of calyptrata and chuquisacensis, in terms of temps. I know there is one person growing involute and calyptrata, but theirs are all green. I believe that is because they don't get temps as cold as it gets for involuta and calyptrata in nature.
And of course, the Ping with the weirdest climate: P. elongata
It seems that in nature, this ping will experience temps in the 70s and low 80s during the day, with extreme temp drops at night, even to freezing. It has 3 different forms of growth, similar to P. heterophylla, and it changes to these different phases based on the wet and dry seasons, similar to Mexican Pinguicula. Definitely one of the most difficult Pings. Mine died after night temps got above 55 degrees fahrenheit. This Ping also grows where it is very windy, but also fairly humid. Quite tricky.