The genus Puya includes more than 200 species of bromeliads and is often regarded as a classic example of a recent, rapid species-level radiation in the Andes. Most Puya species are found at mid-elevations and mid-latitudes south of the equator. Puya chilensis and several others are generally limited to central Chile, a range that is considerably south of most Puya species. (Jabaily and Sytsma 2010)
Although individuals of some Puya species--such as (most famously) the giant, long-lived P.raimondii, which is endemic to the high Andes of Peru and northern Bolivia (Sgorbati et al. 2004)--consist of a single rosette throughout the life cycle and are semelparous, flowering and reproducing just once in their lifetime, individuals of other species (such as P. chilensis) are composed of multiple interconnected rosettes and are iteroparous, flowering and reproducing multiple times. Although many Puya species grow only at high altitudes (greater than 1500 m or even greater than 3000 m), P. chilensis grows at lower altitudes, below 1500 m. (Jabaily and Sytsma 2013)
Schulte et al. (2010) examined the phylogenetic relationships and evidence for hybridization among the seven Chilean Puya species, including P. chilensis.
Rees and Roe (1980) speculated that P. raimondii growing in the Andean puna grasslands of southeast Peru benefit from nutrient supplementation resulting from bird droppings and dead birds trapped in its foliage. Givnish et al. (1984) noted that the spiny foliage of these plants presumably evolved not because of any such benefit (if it indeed exists) but rather to deter consumption of the single terminal inflorescence by Andean bears (which they asserted reportedly destroy the flower spikes of some 90% of individuals in populations of closely related Puya species) or by members of the extinct South American megafauna. Macedoruiz (1977) reported that a cat was "trapped" by the foliage of a P. raimondii, but there seems to be no evidence in the literature that such incidents are common or important to the ecology or evolution of this or related species. Regardless, in a BBC story about a P. chilensis on the verge of flowering in a Surrey greenhouse, the author matter-of-factly passed along a rather dramatically elaborated version of the decades-old Rees and Roe hypothesis, writing: "In the Andes it uses its sharp spines to snare and trap sheep and other animals, which slowly starve to death. The animals then decay at the base of the plant, acting as a fertiliser."
Puya chilensis is a terrestrial bromeliad originating from the arid hillsides of Chile.
An evergreen perennial, it forms large, dense rosettes of grey-green, strap-like leaves edged with hooked spines. The green or yellow flowers are borne on spikes which resemble a medieval mace, and stand up to 2 m (6 ft 7 in) high. Spreading by offsets, Puya chilensis can colonise large areas over time. Growth is slow and plants may take 20 years or more to flower. The outer two-thirds of the leaf blade bears outward-pointing spines which may be an adaptation to prevent herbivores from reaching the center of the plant.[1] The plant is believed to be hazardous to sheep and birds which may become entangled in the spines of the leaves.[2] If the animal dies, the plant may gain nutrients as the animal decomposes nearby, though this has not been confirmed.[2] For this reason, Puya chilensis has earned the nickname "sheep-eating plant".[3] If true, this would make Puya chilensis a protocarnivorous plant. Fibers from the leaves are used to weave durable fishing-nets.[2]
It is commonly found on arid hillsides of the Andes, on north-facing slopes of matorral areas at 300–1,000 m (980–3,280 ft) above sea level.
Puya chilensis is not considered threatened. It is also cultivated in many parts of the world.
In its natural arid environment, plants can be highly flammable and are susceptible to damage from fires that are often the result of human action. Land clearance is an increasing threat.
