''Tropaeolum tuberosum'' (mashua, see below for other names) is a species of flowering plant in the family Tropaeolaceae, grown in the Andes, particularly in Peru and

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, and to a lesser extent in Ecuador as well as in some areas of

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

, for its edible tubers, which are eaten cooked or roasted as a vegetable. It is a minor food source, especially to native Amerindian populations. Mashua is a

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

perennial climber growing to in height. It is related to garden nasturtiums, and is occasionally cultivated as an ornamental for its brightly coloured tubular flowers.

Alternative names

This plant is commonly called mashua in Peru and Ecuador, but other names include: In Boyacá, Colombia it is also named Nabu

Agronomy

The plant grows vigorously even in marginal soils and it competes well with weeds. It is well-adapted to high-altitude

subsistence agriculture Subsistence agriculture occurs when farmers grow food crops to meet the needs of themselves and their families on smallholdings. Subsistence agriculturalists target farm output for survival and for mostly local requirements, with little or no su ...

, and gives high yields; 30 tonnes per hectare are yielded at a height of 3000 metres, but up to 70 tons per hectare have been produced under research conditions.Mashua Ethnobotanical Leaflet, Southern Illinois University
/ref> Its extraordinary resistance to insect, nematode and bacterial pests is attributed to high levels of isothiocyanates. Although mashua is fully domesticated, it can persist in wild vegetation because of its aggressive growth and robustness. In Colombia, it is planted as a

companion crop Companion planting in gardening and agriculture is the planting of different crops in proximity for any of a number of different reasons, including pest control, pollination, providing habitat for beneficial insects, maximizing use of space, a ...

to repel pests in potato fields. alt=Tuber colored as if bleeding blood, Popular Peruvian mashua cultivar Yawar Waqay, meaning "weeping blood", left, 187x187px

Culinary Use

Raw mashua tuber is bitter due to glucosinolates, but the bitterness diminishes after cooking, freezing, or pounding. The tubers comprise as much as 75 percent of the mature plants by dry weight (40 percent is typical for

cereal A cereal is any Poaceae, grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, Cereal germ, germ, and bran. Cereal Grain, grain crops are grown in greater quantit ...

s). Up to 75 percent of dry matter reaches the tubercle.Peace Diaries Workspace
Popularization of mashua may be limited by its strong flavor, and its reputation as an anaphrodisiac. Father Bernabé Cobo records that in the 16th century the Inca used to give enormous amounts of mashua to their troops so that they would forget their wives. However, mashua tubers roasted in traditional earthen field ovens, built at harvest, are considered a delicacy. Also, the raw tubers can be shredded thinly and added to salads, to confer a spicy flavour and crunchy texture. alt=Flowering mashua plants in full bloom, Flowering mashua plants near Quito, Ecuador, 1990, 340x340px

Cultivation as an ornamental

In its native range, mashua is mainly cultivated for its edible tubers, but it has ornamental value in the temperate zone because of its trailing habit and showy, bi-coloured tubular flowers, which appear in summer and autumn. The sepals are orange-red while the petals are bright yellow. In areas prone to frost, it requires some protection in winter. The cultivar ''T. tuberosum'' var. ''lineamaculatum'' 'Ken Aslet' has gained the Royal Horticultural Society's

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

Medicinal properties

Mashua has putative anaphrodisiac effects. It has been recorded by the Spanish chronicler Cobo that mashua was fed to their armies by the Inca Emperors, "that they should forget their wives". Studies of male rats fed on mashua tubers have shown a 45% drop in testosterone levels due to the presence of isothiocyanates. Mashua contains Docosatetraenoylethanolamide, a cannabinoid structurally similar to Anandamide that also acts on the cannabinoid (CB₁) receptor among other structurally related compounds such as N–oleoyldopamine.

References