Mexican Butterwort

Pinguicula moranensis is a Mexican and Central American butterwort that forms flat summer rosettes of sticky, insect-trapping leaves and small succulent rosettes in winter. It is the most widespread Pinguicula in Mexico and one of the most commonly grown butterworts.

Pinguicula moranensis is seasonally dimorphic. During the rainy summer it forms a ground-hugging rosette of 6-8 flat, succulent, obovate leaves up to about 4 inches (10 cm) long, ranging from yellow-green to maroon. These leaves are carnivorous. With the onset of the dry season in October they are replaced by a compact winter rosette, 2-3 cm (about 1 in) across, of 60 to 100 or more small, fleshy, hairy, non-carnivorous leaves, which the plant keeps until rains return around May.

Unusually among Mexican butterworts, it flowers twice a year, from both the summer and the winter rosette. Single flowers, 3-5 cm long with a backward-pointing spur, are borne on stalks 10-25 cm (4-10 in) tall. They are typically pink to purple, often with a white throat, and extremely variable in color; a rare white form exists.

The species is taxonomically difficult because of its variability and large range, and many names have been reduced to its synonyms. Two varieties are recognized: var. moranensis, with open winter rosettes, generally on limestone, and var. neovolcanica, with closed, bulb-like winter rosettes, on volcanic rock.

No natural hybrids are known, but it crosses readily in cultivation and is a parent of many registered cultivars.

Матичен регион: Mexico, Guatemala, El Salvador and Honduras

Климатски зони: Subtropical highland, with wet summers and dry winters

P. moranensis is the most common and widely distributed butterwort in Mexico, found in all major mountain ranges except the Sierra Madre Occidental and Baja California, and also in Guatemala, El Salvador and Honduras. It grows at 800-3,200 m (2,600-10,500 ft), most often in oak, pine-oak or temperate montane woodland, extending into tropical forest and dry shrubland. It favors humid, shady places: stream banks, gullies, road cuts, canyon walls and leaf litter in sandy soil. Its roots serve mainly as anchorage, so it can also grow on boulders, moss-covered rock faces and even tree trunks. The typical variety tends to grow on Cretaceous sedimentary (limestone) outcrops, while var. neovolcanica grows on volcanic rocks of the Trans-Mexican Volcanic Belt.

Зрела големина: Summer rosette leaves to 4 in (10 cm); flower stalks 4-10 in (10-25 cm)

Стапка на раст: Moderate

Тип на стапица: Flypaper Trap

The upper surface of each summer leaf is densely covered with two kinds of glands. Stalked glands secrete droplets of mucilage that give the leaf a wet, buttery look and may lure insects seeking water. When an insect lands, it sticks, and its struggling triggers more glands to release mucilage until it is coated. The leaf edges can curl slightly to bring more glands into contact. Flat (sessile) glands then release digestive enzymes, including amylase, esterase, phosphatase, protease and ribonuclease, and the dissolved nutrients are absorbed through small openings in the leaf cuticle, leaving only the exoskeleton. Small flies are the most common prey. The flower stalks are also glandular and catch insects.

The genus name Pinguicula comes from Latin pinguis, 'fat', for the buttery feel of the leaves.
Its winter rosette is so tight that it looks more like a Sempervivum than a carnivorous plant.
It flowers twice a year, once from each type of rosette.
Plants growing where prey is scarce produce more capture glands; where prey is plentiful, more digestive glands.
Mexican butterworts are mostly pollinated by hummingbirds.
Its chromosome count is 2n = 44.

Alexander von Humboldt and Aimé Bonpland collected the species near Mina de Morán in the Sierra de Pachuca, in the modern state of Hidalgo, during their 1799-1804 expedition. Carl Sigismund Kunth described it in 1817 in Nova Genera et Species Plantarum, making it one of the first Mexican butterworts known to science; the epithet refers to the type locality. William Hemsley later lumped the Mexican species of section Orcheosanthus together under the name P. caudata, a name still applied loosely to this plant. S. J. Casper's 1966 monograph treated P. caudata as a synonym of P. moranensis. In 1999 Sergio Zamudio, after locating the original limestone population, separated var. neovolcanica, and a 2005 molecular study by Cieslak and colleagues suggested placing the species in section Longitubus. It has long been cultivated for its carnivory and attractive flowers.

1. Pinguicula moranensis, Wikipedia
2. Pinguicula, Wikipedia
3. Growing Mexican Pinguicula, International Carnivorous Plant Society
4. Heterophyllous Pinguicula of Mexico and Central America, The Carnivorous Plant FAQ (Barry Rice)
5. Pinguicula cultivation, The Carnivorous Plant FAQ (Barry Rice)