Cinchona pubescens is a small to rather large tree up to 10m high. Its bark tends to turn reddish when cut. Leaves are shaped from broadly elliptic or oval to broadly oblong, are rather thin, conspicuously veined, somewhat pubescent beneath and turn red with age while persisting on the tree. Flowers are in large panicles, pink and fragrant (white to light pink in Galápagos); capsules ovoid fusiform, 2-3cm long, walls firm (PIER, 2002).

In the Galápagos, Cinchona pubescens flowers and fruits almost all year round with peak flowering from August to October and peak fruiting from December to March. Experiments have shown that seeds are viable in the soil for less than a year (Rentería, 2002).

The bark of Cinchona pubescens is used for extraction of quinine compounds.In Galápagos, poles from large trees are used for construction. However, it is not used to make boards (Heinke Jager, pers. Comm., 2005).

In its native range in Ecuador, Cinchona pubescens grows in volcanic soil rich in organic matter but also in very rocky areas, where the roots are exposed to the air. It grows best in disturbed habitats, especially in areas where vegetation was burnt (Acosta-Solís 1945)

Cinchona pubescens spreads rapidly by wind-dispersed seeds. It grows fast (1-2m per year) and produces seed from the age of 4 years. C. Pubescens also produces suckers from roots, and re-sprouts readily from damaged stems. Enormous quantities of small seeds are produced. In Galápagos, saplings grow about 1 metre per year, adult trees however show less growth. Seed production has been observed in small trees of 1.8m height, 1.5cm DBH and 2 years old (H. Jäger, unpubl. Data). Experiments in Galápagos have shown that most seeds do not spread more than about 15m (rarely up to 30m) from the mother plant (Rentería 2002). Despite these findings, the actual distribution suggests a greater rate of spread, considering its original point distribution in 1946 and current distribution of 11000 ha, which represents a likely rate of expansion of 95m or more per year (assuming circular area of occupation).

Cinchona pubescens exhibits an association with arbuscular mycorrhizae. It grows well on acid volcanic soils.

Introduced as a medicinal plant to Galapagos by private farmers, as cash crop.

Rapid spread, fast growth and growth habit (tree with dense canopy) of C. pubescens result in fast invasion and replacement of native vegetation in naturally treeless environments. Shrub and herb layers experience dramatic loss of species diversity, with very few species able to grow below canopy.

Preventative measures: A Risk Assessment of \r\r\nCinchona pubescens for Hawai‘i and other Pacific islands was prepared by Dr. Curtis Daehler (UH Botany) with funding from the Kaulunani Urban Forestry Program and US Forest Service. The alien plant screening system is derived from Pheloung et al. (1999) with minor modifications for use in Pacific islands (Daehler et al. 2004). The result is a score of 9 and a recommendation of: \"Likely to cause significant ecological or economic harm in Hawai‘i and on other Pacific Islands as determined by a high WRA score, which is based on published sources describing species biology and behaviour in Hawai‘i and/or other parts of the world.\"

Physical: Manual methods, including felling adults and pulling out (\"grubbing\") of stumps and saplings, have mixed success. This option is reasonably effective if all roots greater than 2cm in diameter are removed. Removal of saplings is effective, but adult trees can resprout from cut stumps. De-barking is ineffective, even if bark removed from up to 1m of stem: bark regrows and repairs wound, and tree survives.

Chemical: Buddenhagen et al. (2004) undertook a review of control methods used to manage C. pubescens in the Galapagos National Park over three decades; a variety of herbicides and application methods were tested. The study found that a mixture of picloram and metsulfuron (240 and 15g ai/L, respectively) killed 73 to 100% of trees when applied to connecting machete cuts around the circumference of tree trunks (‘hack and squirt’) at concentrations of 5, 10 and 25% in water, with large trees requiring higher concentrations. The authors indicate that although this mixture was effective when applied using other methods, ‘hack and squirt’ was the least labour intensive. The authors suggest that this treatment plan could be used effectively in other locations like Hawaii and Tahiti where C. pubescens is invasive and being controlled.

The Weed Control Methods Handbook provides you with detailed information about the tools and techniques available for controlling invasive plants, or weeds, in natural areas. This Handbook is divided into eight chapters, covering a range of different control methods: manual, mechanical, promoting competition from native plants, grazing, biocontrol, herbicides, prescribed fire, solarization, flooding, and other, more novel, techniques. Each control method has advantages and disadvantages in terms of its effects against the target weed(s), impacts to untargeted plants and animals, risks to human health and safety, and costs.