Pinguicula (Lentibulariaceae) of México – Species, Habitat and Distribution

Reprinted from the Journal Trifid No. 3/2005:

HANS LUHRS 1)
The species of Mexican Pinguicula’s will be discussed here in combination with colour slides taken in habitat during several fieldtrips(1989, “91, “94, 2005). Due to many recent publications of newly described species, about half of the Genus’s number of species (45) occur in the mountains of México. This has given the author/speaker a growing motivation to study these plants, as he has done for the past 17 years. Geographical range of the species as well as their features and habitat will be the main topics of the lecture.

Invalid Link
Pinguicula macrophylla
© HANS LUHRS

The Mexican species occur in the high mountains and their surrounding areas of the Sierra Madre Oriental (North), Sierra Madre Occidental (Centre) and Sierra Madre del Sur (South). Except for a few annuals and those who dwell amongst gypsum hills, most of the Mexican species grow on vertical cliffs or steep slopes and banks were they root in a thin layer of soil, moss, or in pure loam, between 500 and 2950 m. altitude. These habitats are most often found in mixed open cloud forests of oak (Quercus) and pine trees (Abies, Pinus). Only in just a few occasions will they grow (not epiphytically) between moss on trunks and trees (P. moranensis, P. hemiepiphytica), and in one rare occasion even on branches (P. emarginata).

Invalid Link
Pinguicula takakii
© HANS LUHRS

In the state of Nueva León, in the north of México, P. immaculata grows on small banks of gypsum hills that are often called “Islands”. Here they grow together with P. rotundiflora in the same habitat, and both species flower from the winter rosette only. P. gracilis is a dweller of chalk rocks and growing on a thin carpet of soil in the Sierra las Mitras near the city of Monterrey, not far from the border with the United States. In the south of Nueva León and into San Luis Potosi, P. kondoi grows in semi-desert conditions in groups together in small holes and crevices where slope and vertical cliff meet. Different species of Cactus can be found in the same area as well. On the difficult dirt road to Dulces Nombres in the state of Tamaulipas at an altitude of 2000–2500 m. P. cyclosecta grows on vertical cliffs often in a thin layer of moss against bare rock. Of different habitat, P. lilacina is a annual and a pioneer growing mostly in disturbed soil such as red loam trampled by cattle, as to compete as little as possible with other plants, and occasionally on with moss overgrown banks. Another area of gypsum habitat in the state of San Luis Potosi is around the old mine Minas the San Rafael. Between Selaginella, Agave and Hechtia 3 different Pinguicula species can be found here. P. gypsicola grows on the gypsum walls and banks whereas P. takakii, which is a annual, grows more on the lower parts and often hidden between Selaginella on the sides of tiny gypsum islands. The third species P. ehlersiae grows more scattered in small groups under the shade of bush and small Oak trees. They also grow in black soil or on eroded mossy banks and the flowers vary in some degree. Related to the latter but more variable in flowershape and colour is P. jaumavensis. This species has a wider geographical range than P. ehlersiae, and grows vertically on mossy slopes and only occasionally on smaller banks. P. potosiensis was named after the state San Luis Potosi by Speta & Fuchs, were it grows on steep slopes in Oak and Pine cloud forests. Its specific status, however, should be reduced to a synonym of P. moranensis, because of the similarities to the great variation within P. moranensis. A good example is the location of P. moranensis on the edge of a cloud forest near Molango in the state of Hidalgo. Various shapes and coloration can be seen here, not only in the flowers but also in the rosettes and leaf form. Summer and winter rosettes occur together from early winter to early summer. Not far north is the habitat of a very recently described species, P. ibarrae. Its flower resembles a large form of P. agnata, while the summer rosette looks more like that of P. moranensis. The winter rosette is smaller, but with more developed leaves bearing digestive glands and placed in Section Heterophyllum. It grows on steep slopes in Oak and Pine cloud forest at about 1000 m. elevation.

Invalid Link
Pinguicula heterophylla
© HANS LUHRS

The states of Hidalgo and Querétaro are home to P. agnata. Its type locality Barranca de Tolimán lies well hidden in the semi-desert mountainous area in the north-west of Hidalgo. Here the plants grow in cracks and crevices of steep cliffs. At another location in the state of Querétaro, P. agnata grows in cracks and ridges of a rocky slope and is flowering from the winter rosette. Close nearby P. moranensis grows in the same type of habitat. P. colimensis is known from a small area in the lower mountains of Colima at 450 m. elevation. They mainly grow in cracks on steep vertical limestone cliffs and only occasionally on banks sparsely covered with mosses. They flower duringt he summer only. The leaves of P. oblongiloba are quite different from those of P. moranensis, being more rounded with a long petiole. This species grows on slopes in mixed Pine and Oak cloud forests at 1600-1800 m. altitude, like here in the state of Michoacán. Here they grow together with the small flowered perennial P. crenatiloba, which is more abundant in the mossy parts of the slope were they form small groups. In the state of Guerrero, P. crenatiloba was found on several locations and also growing together with P. heterophylla and P. parvifolia on small banks in mixed Pine and Oak forests. In the east of Oaxaca state grows P. rectifolia like carpets on steep and moist cliffs in the narrow canyon of El Boquerón. The winter rosettes are quite similar to those of P. moranensis, and it is also questionable whether it is a form of the latter rather than a separate species. Many species occur in Oaxaca, like P. heterophylla growing on a steep slope in a mixed Pine and Oak forest in the Sierra Madre de Oaxaca. Here they grow in red loam covered with a layer of Pine needles and Oak leaves, and flowerin early summer with new leaves appearing from the winter rosette. When examining about a 100 plants in September 1991, only 3 plants showed new growth in the form of a plantlet growing at the end of one of their leaves, a common feature which occurs in P. medusina.

Further east on the edge of Sierra Zempoaltépetl is the habitat of P. laueana. It grows in moss as well as patches of black soil on steep vertical cliffs in cloud forest at 2300 m. altitude. The colour of the flowers is unique and a rare feature within the Genus Pinguicula. Crossing the Sierra Madre Oriental in the north of Oaxaca, at least 4 Pinguicula species can be found; P. heterophylla, P. moranensis, P. orchidioides and P. hemiepiphytica. They all inhabit mixed Pine and Oak cloud forests between 2200-2700 m. altitude. Here P. moranensis grows on ridges and in cracks of rocky cliffs in large groups together. Flowers from different locations show their colour variety. Of different habit is P. orchidioides, growing on steep rocky slopes. This species has a unique feature in making up to 8 cm long stolons that grow from gemmae. At the end of each stolon a new plant starts to grow. The plant itself shows some similarities with P. alpina from Europe; however it lacks a true hibernacula and has a type of onion instead. The flower also is quite different from others. P. hemiepiphytica grows on moist slopes and banks in the higher parts of the Sierra Madre Oriental. Referring to its name, a half-epiphyte, it is adapted in growing on with moss covered trees up to 12 m. high in extreme cloud forest next to Catopsis and Orchids like Epidendrum vitellinum and E. ibaquense.

Invalid Link
Pinguicula crassifolia
© HANS LUHRS

The Puebla-Vera Cruz border is the habitat of P. emarginata, growing in almost sub-tropical climate in cloud forest at 1400 m. altitude. They inhabit constantly wet and dripping cliffs were they grow in a algae like substrate and flower all year through. One of the states where P. parvifolia occurs is México. Here they grow on steep grassy slopes in mixed Pine and Oak forest. Despite of its name, the autumn rosettes grow up to 10 cm. in diameter. One of my favourite places to visit are the high mountains of El Chico Nat. Park in Hidalgo, were cloud forest still exist at almost 3000 m. altitude. Within the Nat. Park as well as the surrounding areas, P. acuminata inhabits shady slopes and banks growing in red loam and eroded moss. They flower from the winter rosette which is buried in the soil, and gives you the idea of a flower-stalk with no plant attached to it. The leaves of the autumn rosette grow easily to 10 cm in length. A different type of habitat is that of P. crassifolia, growing in a thin layer of moss on the rocky surface of steep cliffs in shaded cloud forest at 2900-2950 m. altitude. They also flower from the winter rosette only.

Through these slides, the author/speaker has hopefully given you an image of how Mexican Pinguiculas thrive in their natural habitat, and about the differences between the species as well as the variation within some of them, in a country such as México with a still growing number of newly found and described species.


1)
Hans Luhrs – a specialist in the Pinguicula genus, especially in the Mexican species, Netherlands.
Krayenhoffstr. 51, 1018 RJ Amsterdam, Netherlands.