All species › Lamiales › Bladderwort family › Pinguicula involuta
Pinguicula involuta
One of the oldest South American carnivorous plants in the literature: Ruiz and Pavón found it in the late eighteenth century inter muscos — among the mosses — in the cold, wet highlands of central Peru, and described it in their Flora Peruviana. The epithet refers to the leaf margin, rolled so far inward that the leaf becomes almost a gutter.
Identification
A small rosette of thick, oblong leaves fifteen to twenty-five millimetres long and eight to twelve wide, lying flat on the moss. The character the species is named for is obvious close up: the margin is rolled inwards along its whole length, far more strongly than in most butterworts, so that the leaf looks narrower from above than it is. The underside is flushed brownish purple, the upper surface olive-green and glistening with glandular droplets. The scapes are slender and each carries a single flower ten to twelve millimetres across, violet to pale violet and sometimes almost white, with a spur of three to four millimetres that curves distinctly away from the corolla. Flowering is remarkably long: plants are in bloom from May into December.
Similar species
In Bolivia the species can occur alongside Pinguicula jarmilae, which sits lower, has larger flowers of thirteen to fifteen millimetres and a short straight spur; the curved spur of P. involuta is the quickest character here. Further north in the Andes stands P. calyptrata, with broader leaves up to thirty-five millimetres and a short conical spur of at most three and a half millimetres. In case of doubt the strongly inrolled margin is the best field character: none of the neighbouring species rolls the leaf in so far. Out of flower the brownish-purple underside is a second clue.
The trap and how it works
A flypaper trap built for a sloping or vertical, permanently wet surface. The stalked glands hold a droplet that barely dries in the high humidity; the sessile glands beneath release digestive enzymes as soon as prey is lying on the leaf. The inrolled margin matters more here than in most species: because the leaf already forms a gutter at rest, the digestive fluid stays with the prey instead of running off down the mossy rock. The catch consists of the small flies and springtails that swarm in the moss carpet of spring-fed habitats. What remains after a while are black husks glued into the groove of the old leaf.
Habitat and ecology
Wet, moss-covered rocks and steep slopes between two thousand seven hundred and three thousand four hundred metres (R1), in the cold, misty belt above the cloud forest and up into the open montane vegetation beyond (R5). The holotype was already recorded as growing among mosses, and that is still the best description of the site: a closed, saturated layer of moss and liverwort on stone, fed by seeping water rather than by soil. Temperatures stay low all year and swing more between day and night than between seasons.
Distribution and elevation
The species occurs in central and southern Peru, with records from the departments of Pasco and Huánuco, and further south in Bolivia in the yungas of La Paz and Cochabamba. It is therefore not endemic to one country, but it is confined to a narrow altitudinal band along the eastern flank of the Andes. Our own species list names Ecuador and Peru; the Bolivian part of the range is well documented, while confirmed Ecuadorian records are lacking — there P. calyptrata takes over. The elevation is much the same throughout: between two and a half and three and a half thousand metres.
- Recorded (one-degree cells)
Forms and variation
No wild varieties or subspecies are recognised. Such variation as exists concerns mainly flower colour, which runs from clear violet through pale lilac to almost white, even within a single population; that is no basis for distinguishing forms. Plants from the highest parts of the range stay smaller and have a more compact rosette than those in sheltered, mossy rock niches. No natural hybrids are reported. Because the species stands genetically close to P. calyptrata and P. jarmilae, future work may still shift the species limits here.
Where and when to see it
Search the rocks, not the grass. The best places are steep, north- or east-facing faces along mountain paths and streams above the cloud-forest line, where moss grows in thick cushions on the stone and water seeps through it continuously. The rosettes are small and green on green; stand close to the wall and look in raking light. Because flowering runs from May to December the season is generous — but the plant is easiest to find in the wet months, when the mosses are growing actively and the scapes rise clear of the cushion.
Conservation status
The species has not been assessed for the global IUCN Red List and is not listed in CITES. There is thus no international category, and no recent count of populations either. What is known: the range spans hundreds of kilometres along the eastern Andean flank across Peru and Bolivia, but within it the species occupies a very particular site — wet, mossy rock in a narrow altitudinal band. Distributions of that kind are vulnerable to changes in the fog belt and to road building, which in the Andes runs precisely along steep slopes. Without targeted survey little can be said about the trend; the absence of an assessment is a gap here, not a clean bill of health.
Scientific name
Pinguicula involuta | Ruiz & Pavón, 1798
Described by Hipólito Ruiz López and José Antonio Pavón in 1798, in Flora Peruviana et Chilensis 1: 20. The type material was collected in cold, wet highlands near Pillao and Panao Huassahuassi, in present-day Peru, among mosses. The species name involuta is Latin for "rolled inward" and refers to this species' strongly inrolled leaf margins.
World Checklist of Vascular Plants (WCVP), via Plants of the World Online (POWO), Royal Botanic Gardens, Kew.