Contributed by Joel Felix, Oregon State University
While thinking on the topic for my contribution to the Weeders of the West forum this time around, it hit me that for once we will look at the positive side of some weeds. In this case, Amaranth spp. Amaranthus is a cosmopolitan genus that belongs to the family Amaranthaceae, which is composed of 70+ species found worldwide. Invariably, many members of the Amaranthus family are considered weeds in the United States and worldwide. Among the 70+ species of Amaranthus, 17 are cultivated for edible leaves, and 3 are cultivated as food grains (Sarker et al., 2020). In the United States, Amaranths are broadly called ‘pigweeds’ e.g. redroot pigweed, Powell amaranth, prostrate pigweed, Palmer amaranth, waterhemp, spiny pigweed, smooth pigweed, and tumble pigweed. There are thousands of names for the many Amaranth species worldwide. Amaranth is an interesting genus that is considered weedy while some members are grown ornamentally as well as for grain and/or as a green vegetable. In fact, Amaranth was an important crop for the Aztecs, who used the grain as both food and for religious rituals.
Amaranth is native to Central America where it is cultivated for culinary usage, but has spread nearly worldwide and more so in the tropical world through various routes. Most members of the Amaranth family are annual with simple leaves arranged alternately along hairy or smooth stems. Because of its more efficient C4 photosynthesis pathway, it grows rapidly under summer heat, and it is believed to tolerate acidic, alkaline, or saline soil conditions. Its high protein content (only from grain) makes a valuable impact on human nutrition in various countries.
This brief article will address the leafy amaranths used as vegetables in East Africa and other parts of the continent. Amaranths used as veggies carry various local names such as ‘‘mchicha’’ in Tanzania, ‘‘terere’’ in Kenya, ‘‘aluma’’ and ‘‘heberxefa’’ in Ethiopia, and ‘‘Ddodo’’ in Uganda and Rwanda, and are a popular traditional African leafy vegetable with a long cultural tradition in East Africa and other regions on the continent. Amaranthus cruentus, Amaranthus dubius, and Amaranthus hypochondriacus are the most widely grown species in Tanzania and other countries in Africa (Fekadu Fufa Dinsa et al., 2019). Whether growing unattended or cultivated, Amaranthus dubius leaves commonly have dark green hues or dark green with splashes of dark purple overlay in the leaf’s center (Figures 1 and 2). Amaranthus dubius tends to have a slow early growth, branching habit, and tendency for late flowering that prolongs vegetative growth and allows multiple leaf harvests (Fekadu Fufa Dinsa et al., 2019) until the plant reaches approximately 1.5 meters.