The genus Pinguicula is a fairly decent sized group as far as carnivorous plants go, with somewhere approaching 100 species that can be found from the tip of South America up straight through to Canada, across Europe and north-central Asia into Japan and Korea. It's composed of several distinct groups, including the northern-temperate plants that form hibernacula to survive harsh winter conditions, the European warm-temperate plants like the annual P. lusitanica (which I will probably soon need to do a blog of its own on) and perennial P. hirtiflora, the southeastern US warm-temperate plants, Caribbean and Latin American tropical species, the South American cold-temperate plants, and the best known are the Mexican butterworts, the most diverse group with annuals, year-round carnivorous perennials, and the heterophyllous winter-succulent or bulb-dormant species. All of them are flypaper carnivores, with tiny tentacle glands coating their leaves and mildly active movement to help digest whatever they catch; this slimy, sticky covering is where the genus name comes from, which translates roughly as "little greasy ones."
Out of all these species though, of the many various shockingly beautiful colors they bloom in, there's only one that sports red flowers.
Pinguicula laueana is an endemic to the Sierra Mixe mountain range of north-central Oaxaca in Mexico, recorded from high montane pine-oak and cloud forests anywhere from 2300-3500 meters in elevation where it grows as a lithophyte and occasionally opportunistic epiphyte on rock faces and seeps and the trunk bases of the local trees. Plants may grow to nearly 18 cm in diameter in some cases, with rosettes of overlapping, broad ovular carnivorous leaves that in many forms will tint to fully flush rich shades of crimson to burgundy. Or, at least that's their summer appearance; this is a heterophyllous species, meaning in winter it typically expects the environment to dry out, so they develop a dense mound of succulent, somewhat hairy green or red-tinted pointy leaves to ride out the dry season. Much current literature and those who've grown these plants for decades will refer to this winter season as a dormancy, but this is not quite accurate; the species that form bulbs halt all growth an enter a static state, but the winter rosette species continue to actively photosynthesize at this time and many even bloom, something a dormant plant will never do.
As beautiful as the rosettes are though, as the first image in this blog demonstrated what this species is really known for is its shocking flowers. In the wild the blooming season typically arises near the end of the dry season into the start of the wet season, the plants transitioning between growth forms and sending up one to several sticky stalks that each sport a singular bloom that's not only beautiful, but often BIG. As with many of the traits of this species size can vary, but often the petals themselves can be nearly 4 cm across, the length of the flower along the spur up to 8. These flowers can have fairly large, rounded petals, or slimmer and more rectangular, and can range in hues from electric fuchsia or magenta to light scarlet or red-orange, brick red, or the famed glowing crimson forms like the beauty I am lucky enough to grow (for no photo really captures the true hues that glow off these flowers).
The size, color and spur length of these flowers all hint toward a particular mystery that surrounds many butterworts, particularly the Mexican species: what pollinates them? Most of the species of this region will not self-pollinate, and so require an animal of some sort to cross different clones, but flies, gnats, and bees don't always fit within the blooms like they do in the more broad-tubed Andean or southeast US and northern temperate species flowers. For these Mexican species, there are two prime options that seem to fit, and for those with red or brilliant pink and purple flowers, one candidate that stands out in particular: the hummingbird.
Hummingbirds have a particular liking for flowers in the red and purple spectra, and their long beaks and tongues make them excellent retrievers of nectar within deep, narrow blooms. In turn, their sticking of their faces way down deep in the flower like that means some part of their beak is likely to sweep the pollen out of the flower as they withdraw, and deposit it on the stigma lobes of the next bloom they visit. Another possible option as the pollinator is the hawkmoth, of which most species also have very, very long probosces; they however tend to be more attracted depending on species to pink, purple, and white blooms, which cover most of the variation of the Mexican butterwort species beyond this special one. Little hard evidence however has been collected yet to confirm that these pollinators are in fact the ones that the butterworts use, and more studies in situ are needed to nail down an answer.
I like though the idea of the birds being involved with this plant....
Anyway, in cultivation people can take over the pollinator role, and often have to create new clones of species and a vast number of hybrids; sadly the gorgeous color of P. laueana flowers rarely comes through in its crosses unless one succeeds with the small number of backcrosses that are possible, but it still seems to manage to enrich the tones of whatever other species it's crosses with. As I write this I'm awaiting the results of whether or not I've been successful crossing mine with P. gigantea, moranensis 'Huahuapan' x emarginata, and sp. Tonala "ANPA A" x emarginata (some of the few hybrids where I think a complex cross may be possible), and with a second bloom on the way hope to also manage a new cross straight with emarginata, and maybe a species or two more if any decide to bless me with blooms.
The pollen hides behind the larger lower lobe of the stigma just inside (or in some other species deep inside) the flower's tube, on two anthers that curve up underneath. swiping under the stigma draws pollen out without dropping it on the receptive surface, very effectively avoiding self-pollination and encouraging genetic diversity via outcrossing. Once a flower has been pollinated, one to several days later the whole corolla shrivels up and falls off, and the ovary swells as the seeds develop before it eventually cracks open into two halves, releasing sometimes dozens of small, brown or blackish seeds. The seeds of the Mexican species typically don't store well and have a short viability window, so must find a suitably moist location quickly to land and germinate.
Growing this and other heterophyllous Mexican butterworts is relatively straightforward. Everyone has their own mix that works best for their particular conditions, but they tend to like a heavily or even pure mineral soil. My mix is roughly something like a 3:3:1 perlite/sand (or blasting abrasive nowadays, since it's cheaper here and neutral especially once it's been washed a time or two), gritty and airy but with just enough organic material to wick up moisture to keep the pot damp through the growing season. Most of these species don't particularly like being soaking wet, as this can invite crown rot. Some people find that additives or large components in the soil or crushed shells, limestone, or calcium solutions help boost growth for some species as well. This is a field where everyone has to experiment to find what works best for them.
The plants don't need particularly large pots either; their roots are designed as anchors more than anything else, and so a pot needs only be a few inches wide, or most fittingly about as wide as the plant, and maybe a couple of inches deep just to keep the soil in. Success is also often had on volcanic rock plantings, where the plants are put into drilled holes or natural crevices and the rock set in water to wick up. Butterworts should be fed on a moderately regular basis to keep happy and growing well, with small bits of crushed bloodworms or other fish foods, dilute fertilizers, or whatever small gnats and flies they can capture on their own.
The Mexican species also propagate easily; if you don't have the experience or enough genetically unique plants to get seeds, pullings of the leaves (not cuttings, but pullings) work very well when placed on the soil. Some say that the winter leaves right near the end of that season work best, but I have never had much issue getting the summer carnivorous ones to bud from the leaf bases either (winter leaves might tend to just fall off the plant a whole lot easier though, with at least a few species). Each time a plant flowers it also often divides the main crown in two, eventually forming either mounds or pushing each other apart into carpeting colonies. All these individual plants can be left growing together, or separated as desired.
Keep in mind as you grow P. laueana or many of its other Mexican relatives too though: the plants currently in cultivation are often descended each from only a handful of clones collected out of the wild years or decades ago. Most of the Mexican species have only had one or two legal collections that have occurred due to government regulations there, and even field trips to photograph these species are sometimes few and far between, in no small part because many of them are highly restricted in their ranges, found only in isolated patches or a handful of mountain peaks or river gorges where it can be difficult to reach (physically or because of the dangerous social environment) or simply unknown to most of the world. They are often considered if not officially classed as vulnerable to even endangered, and so wild populations require as much protection as they can get. Appreciate the plants that we have to grow now, and if you can, help support the educators and in-field conservationists who seek to keep those wild populations safe and stable for appreciation far into the future as well.
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