Mashua :: Botany

Mashua Mashua (Tropaeolum tuberosum Ruiz & Pavà ³n 1802), also known as isanu, cubio, aà ±u, ysaà ±o, or puel, is a tuber crop indigenous to the Andean highlands and is of economic value as a food and medicinal crop. This root crop ranks fourth in importance in the Andean region after potato, oca, and ulloco (NRC, 1989). Of the Andean tubers, mashua is one of the highest yielding, easiest to grow, and the most frost resistant. Mashua is cultivated in the Andes of Bolivia, Peru, Ecuador, Columbia, and Venezuela (Gibbs et al., 1978). It is currently being grown experimentally in New Zealand and the Pacific Northwest to evaluate its potential for worldwide cultivation (Soria et al., 1998). The tubers of T. tuberosum are an important source of food for around 9 million people living at elevations of 2500 to 4000 m throughout the Andes mountains (King and Gershoff, 1987). Mashua is an annual, herbaceous climber that belongs to the family Tropaeolaceae which includes about 100 species. Tropaeolum tuberosum is closely related to the garden Nasturtium, Tropaeolum majus L. (Vaughn and Geissler, 1997). Tropaeolum tuberosum grows to over 1-1.5 m in diameter and 0.5-0.8 m high with slender and cylindrical aerial stems. Both erect and prostrate forms of mashua are known. Mashua has alternate, circular, peltate, 3- to 5-lobed leaves, and glaborous, twining stems that attach themselves to other plants by tactile petioles (NRC, 1989). The flowers are long-stalked, solitary, axial, bisexual. The color of the flowers range from dark yellow, orange, and scarlet. The fruit is a schizocarp with three indehiscent carpels that contain joined seeds lacking endosperm (NRC, 1989, Torres et al., 1992). The seeds are abundant and viable at maturity although since mashua is propagated asexually many asexual forms have arose which occasionally set seed. The tubers of Tropaeolum tuberosum are produced on axillary stolons which enlarge to form terminal, elongate tubers which are slightly roughened from enlarge scale leaves (Sperling and King, 1990). The tubers vary in color from white to yellow with occasional variants that are purple or red. They are often striped or mottled red or purple, especially underneath the eyes. The flesh of the tuber is yellow (NRC, 1989). History Mashua has been cultivated since ancient times and tubers are often found in archeological sites (NRC, 1989). Pre-Incan pictograms representing potato, ulluco, oca, and mashua have been found which show evidence the importance of these tubers even in those times (Hodge, 1946).