Pinguicula elizabethiae is a perennial rosette-forming insectivorous herb native to the Mexican states of Querétaro and Hidalgo. A species of butterwort, it forms summer rosettes of flat, succulent leaves up to 5 centimeters (4 in) long, which are covered in mucilaginous (sticky) glands that attract, trap, and digest arthropod prey. Nutrients derived from the prey are used to supplement the nutrient-poor substrate that the plant grows in. In the winter the plant forms a non-carnivorous rosette of small, fleshy leaves that conserves energy while food and moisture supplies are low. Single purple flowers appear between July and October on upright stalks up to 75 millimeters long.
The species was described in 1999 by S. Zamudio, who placed in the section Orcheosanthus. It is closely related to P. colimensis.
The generic name Pinguicula is derived from the Latin pinguis (meaning "fat") due to the buttery texture of the surface of the carnivorous leaves. The specific epithet elizabethiae refers to Zamudio's friend Elizabeth Arguelles, an enthusiastic collector of flora from Querétaro.
Plant characteristics
Habit and phenology
Like many Mexican butterworts, P. elizabethiae is seasonally dimorphic, in that it undergoes two distinct growth habits throughout the year. During the summer when rain and insect prey are most plentiful, the plant forms a ground hugging rosette up to 12 centimeters (5 in) in diameter and composed of obovate–spatulate to suborbicular–spatulate leaves. These leaves are carnivorous, having a large surface area densely covered with stalked mucilaginous glands with which they attract, trap, and digest arthropod prey, most commonly flies. These so-called "summer leaves" are replaced by "winter rosettes" of small, glandless succulent leaves with the onset of the dry season in late fall. This protective winter rosette allows the plant to undergo winter dormancy until the first rains begin in spring. Flowers born singly on upright 35–75 millimeter (–3 in.) peduncles emerge from July–October.
Leaves and stolons
The leaf blades of the summer rosettes of P. elizabethiae are smooth, rigid, and succulent, and green in color. The laminae are generally obovate–spatulate to suborbicular–spatulate, between 35 and 72 millimeters (–3 in.) long and 10–53 millimeters (–2 in.) wide, and have slightly involute margins. The leaf bases are covered in 5–10 millimeter multicellular trichomes.
The "winter" or "resting" rosette of P. elizabethiae is 10–20 millimeters (– in.) in diameter and consists of 60 to 125 small, compact, fleshy, non-glandular leaves. These are each 5 to 17 millimeters (– in.) long and two to four millimeters (– in.) wide, spatulate to oblong-spatulate, obtuse, and densely covered with 5–10 millimeter multicellular trichomes.
As is typical in the genus, the upper lamina surface of the summer leaves is densely covered by peduncular (stalked) mucilagenous glands and sessile (flat) digestive glands. The peduncular glands consist of a few secretory cells on top of a single-celled stalk. These cells produce a mucilaginous secretion which forms visible droplets across the leaf surface. This wet appearance probably helps lure prey in search of water; a similar phenomenon is observed in the sundews. The droplets secrete only limited enzymes and serve mainly to entrap insects. On contact with an insect, the peduncular glands release additional mucilage from special reservoir cells located at the base of their stalks. The insect struggles, triggering more glands and encasing itself in mucilage. The sessile glands, which lie flat on the leaf surface, serve to digest the insect prey. Once the prey is entrapped by the peduncular glands and digestion begins, the initial flow of nitrogen triggers enzyme release by the sessile glands. These enzymes, which include amylase, esterase, phosphatase, protease, and ribonuclease break down the digestible components of the insect body. These fluids are then absorbed back into the leaf surface through cuticular holes, leaving only the chitin exoskeleton of the larger insects on the leaf surface.
Flowers
Pinguicula elizabethiae produces one to five flowers during each flowering period. These are borne singly on upright flower stalks which are 3.5 to 7.5 centimeters (–3 in.) long and are covered in glandular trichomes. Most flowers are pinkish, but colors ranging from violet to off-white have been observed.