Amaranthus standleyanus aka Indehiscent Pigweed

Amaranthus standleyanus lives for one year. It belongs to the amaranth family, Amaranthaceae. Its common name is indehiscent pigweed. It is native from Bolivia into northern and central Argentina. Kew places it in a subtropical region. Useful Tropical Plants says it has become naturalized in Spain. This means it now grows wild there. In Britain, it grows now and then on disturbed ground. These records show it can grow beyond its native range.

Plants reach about 2.3 feet (0.7 metres) in height. Stems may stand upright or lean along the ground. Each plant has both male and female flowers, borne apart. Wind moves the pollen between flowers. Plants can also use their own pollen to make seeds. The seeds are very small, and plants can make many. The sources do not state the flowers' colour or season. They give no full account of leaf shape or fruit form.

PFAF says frost can harm this species. It accepts sandy, loamy, and clay soils that drain well. Soil can be mildly acid, neutral, or mildly alkaline. It needs light, not shade, and prefers moist soil. Useful Tropical Plants calls for rich soil in a warm spot. The site should get sun and shelter. PFAF bases its growing notes on the wider genus's needs. Thus, how well it grows in British gardens is not clear. PFAF says to sow outdoors in late spring. Start earlier seeds under glass, then plant out after frost. Warm soil helps seeds sprout. Cold soil gives poorer results.

People gather wild leaves and seeds for food. They cook the leaves to use in place of spinach. The seeds need cooking, too, and give food of value. Whole seeds form a gel-like mass when cooked. The small seeds are hard to handle and chew. Some may pass through the gut without being fully digested. The whole plant also gives yellow and green dyes. Neither source lists a use as medicine for this species.

Insects that chew leaves can harm the plants. Useful Tropical Plants flags a risk of becoming a weed. PFAF marks that risk as absent. Take care, given its many seeds and spread on disturbed sites. Both sources warn that leaves may build up nitrates. This can occur in soil rich in nitrogen. They link this risk to the use of chemical fertilizers. Their food-use notes do not mean the plant is safe in all cases.