Giant Butterwort

Pinguicula gigantea is a Mexican butterwort from the steep slopes around San Bartolomé Ayautla in Oaxaca, with some of the largest leaves in the genus, up to about 6 inches (16 cm) long. Unusually, both surfaces of its leaves are sticky and catch insects.

P. gigantea is a perennial rosette plant with a short, simple stem and numerous fibrous roots. Its semi-erect, bright green leaves are oblong to obovate with rounded tips, 60-145 mm (up to 165 mm) long and 40-70 mm (up to 80 mm) wide, and are densely covered on both sides with sessile and stalked glands. The epithet gigantea refers to these large leaves.

Most Mexican butterworts alternate between carnivorous summer leaves and a compact rosette of succulent winter leaves. P. gigantea is barely heterophyllous: its winter leaves, 35-60 mm long, differ from the summer leaves mainly in size, and it forms no distinct winter rosette.

One to five flower stalks, 15-18.5 cm (6-7 in) tall, each carry a single flower 28-33 mm long including the spur. The corolla has nearly equal lobes, pale purple-violet to whitish lilac with a violet margin, and a green tube with violet lines. Forms with blue, white and dark purple flowers are grown. Hans Luhrs placed the species in section Agnata, related to P. agnata.

Região Nativa: Near San Bartolomé Ayautla, Oaxaca, Mexico

Zonas climáticas: Tropical, with a wet and a dry season

The type locality is on steep slopes near San Bartolomé Ayautla, Oaxaca, at 500-800 m (1,600-2,600 ft). Its discoverer, Alfred Lau, found it on fully exposed rock walls in hot tropical sun, growing with Tillandsia streptophylla, and believed it grew along the south side of the steep walls of the Río Uruapan valley up to above Ayautla. Like other Mexican butterworts it experiences a wet season and a dry season.

Tamanho adulto: Leaves 2.4-5.7 in (6-14.5 cm) long, occasionally 6.5 in (16.5 cm); flower stalks 6-7 in (15-18.5 cm)

Taxa de crescimento: Moderate

Tipo de armadilha: Flypaper Trap

The leaves are densely covered with sessile and stalked glands that secrete a sticky mucilage. Small insects such as fungus gnats stick to the surface and are digested on the leaf. Unlike almost all other butterworts, P. gigantea has stalked glands densely on both the upper and lower leaf surfaces, so its semi-erect leaves catch prey on both sides.

Its leaves are among the largest in the genus.
It catches insects on both sides of its leaves, a trait shared by very few other butterworts.
It was distributed in cultivation under the name Pinguicula 'Ayautla' before it was formally described.
Leaves pulled from the rosette, including the white base, sprout new plantlets.

The botanist Alfred Lau collected the plant in 1987 near San Bartolomé Ayautla in the state of Oaxaca, and told the story of its discovery in the newsletter of the International Pinguicula Study Group in 1993. Plants were raised from seed in cultivation, and in December 1995 Hans Luhrs described the species in the journal Phytologia, from cultivated plants and Lau's habitat photographs. The holotype is deposited in the herbarium TEX.

Before then the plant circulated among growers as Pinguicula 'Ayautla', a name Peter D'Amato used in The Savage Garden (1998) that is now treated as a synonym of P. gigantea. Luhrs noted that its uniform leaves fit section Agnata imperfectly; later reclassifications merged several Mexican sections, including Agnata, into section Temnoceras.

1. Luhrs, H. (1995) A new species of Pinguicula (Lentibulariaceae) from Mexico. Phytologia 79(6): 389-392
2. Pinguicula gigantea, Wikipedia
3. Pinguicula gigantea, A World of Pinguicula (pinguicula.org)
4. Heterophyllous Pinguicula of Mexico and Central America, The Carnivorous Plant FAQ (Barry Rice)
5. Growing Mexican Pinguicula, International Carnivorous Plant Society
6. Pinguicula cultivar register, Carnivorous Plant Names resource, International Carnivorous Plant Society