Quila (Chusquea quila Kunth) is a perennial woody grass of the bamboo family which is native to the humid forests of the South American highlands in Chile, Argentina and Brazil. It covers large areas in its native range and it is used as a dry season browse by cattle farmers in Southern Chile. The periodic flowering of quila has been linked for centuries to devastating rodent outbreaks, resulting in a negative perception of the plant by local farmers.
Morphology and life cycle
Chusquea quila is a perennial woody grass that reaches up to 10 m. Its culms are solid (not hollow as in other bamboo species) only 2-5.5 m tall but they are densely ramified (up to 4 levels), resulting in a large plant biomass. Quila can be decumbent or climbing. In the latter case, it attaches itself to trees, reaching a height of more than 20 metres, which allows it to place its foliage in the middle strata of the forest. The culms are 7-8 mm in diameter, with nodes in which numerous flowering branches of up to 35 cm in length are inserted. Each node can contain up to 40 flowering branches. The leaves are lanceolate-elliptic, 10 to 12 cm long, with 7 to 9 parallel nerves, sharp margins, a marked and prominent central nerve, and a sharp and punctured apex. The inflorescence is a large panicle, measuring 14-18 cm, with alternating long branches of 6-10 cm. The fruit is a caryopsis. Chusquea quila has rhizomes that helps the plant to propagate (Roasio et al., 2003; Chilebosque, 2020; Belov, 2020). Chusquea quila often forms monospecific thickets called quilantos, quilantales or quilantares. It can constitute a dense and imprenetrable underbrush (Chilebosque, 2020).
One characteristic of Chusquea quila is its gregarious and periodical flowering. The average cycle length, once believed to be about 30 years, is now estimated to be about 12 years. When a bloom happens, 70-90% of the total population flowers at the same time during the spring-summer months over a relatively large area. The plant defoliates during flowering and has no vegetative growth. Seed dissemination (mast seeding) starts in the summer and peaks in January (50 million seeds/ha). The plants later dry and die, and the next generation emerges from the seeds in the following years. Chusquea quila takes about 5 years to reach a height of more than 2 m, and the biomass is reconstitued after less than 7 years (Roasio et al., 2003; Soto Vidal, 2005).
Uses
Quila browse is used by cattle farmers in Southern Chile as forage when pasture becomes scarce during the winter period (Roasio et al., 2003; González Cangas et al., 2006). Like other bamboo species, it is a multipurpose plant and is used in handicraft work, lightweight housing, fences, ethnomedicine, and human food (bamboo shoots). The seeds used be ground into a flour by indigenous populations. Chusquea quila is being investigated as a potential biomass resource for the industrial production of cellulose and lignin (Oliveira et al., 2016; González Cangas et al., 2006; Wilhelm de Mösbach, 1955). Quila is sometimes cultivated as an ornemental species, though less so than other Chusquea species (Cooper, 2007). While bamboos have a major cultural and economic importance in Asia, this is not the case for Chusquea species in South America. Rural populations in Southern Chile, particularly the Mapuche, have a conflictual relation with quila. They perceive it not only as an invasive and often useless plant, but also as the source of natural calamities, due to the fact that the flowering described above is followed by devastating rodent outbreaks and forest fires (See Environmental impact). This explains why quila, despite being widespread, has remained underutilized and little investigated until the 2000s, notably as a source of livestock fodder (Roasio et al., 2003; González Cangas et al., 2006).
