Hierba mora: what it is, taste and how to cook it

What is it?

Black nightshade, also known in Spanish as hierba mora, yerba mora or tomatillo silvestre, is a traditional quelite of central and southern Mexico belonging to the species Solanum americanum, a plant of the Solanaceae family related to the tomato, the green tomato and the potato. It grows wild in milpas, wastelands and crop margins during the rainy season, especially in Puebla, Tlaxcala, Oaxaca, Veracruz, Chiapas and the State of Mexico. Its tender leaves are consumed cooked as a quelite and its small berries, when ripe and shiny black, are eaten fresh or used in salsas. The plant is one of the few wild Solanaceae used as food in Mexico and forms part of the rural agri-food heritage, although its consumption requires knowledge because the green berries and raw leaves contain toxic alkaloids that are eliminated by cooking.

Origin and history

Black nightshade is a plant of ancient presence in Mesoamerica, mentioned in colonial sources under names such as 'quilitl negro' or 'tomatl silvestre'. Sahagún, in the Florentine Codex, describes several plants of the genus Solanum used by the Nahuas, both as food and as medicine. CONABIO documents its use in numerous indigenous communities of the country from pre-Hispanic times. Its distribution is almost cosmopolitan: it is considered native to the tropical and subtropical regions of the Americas, but it also grows in Asia and Africa. In Mexican traditional medicine, the Digital Library of the UNAM records its historical use to treat skin complaints, ulcers and joint pains through poultices and baths. After the conquest, the knowledge about which parts to consume was kept within the oral traditions of rural peoples, avoiding confusion with the poisonous Solanaceae Solanum nigrum sensu stricto or with other toxic species of the same genus. Today it is considered a minor but significant quelite within the Mesoamerican milpa.

Characteristic ingredients

Solanum americanum is an annual or short-lived perennial herbaceous plant, reaching between 30 and 90 centimetres in height, with alternate oval leaves and small white flowers with yellow anthers arranged in clusters. Its fruits are globose berries that turn from green to shiny black as they ripen and measure between five and eight millimetres. The edible parts are the cooked tender leaves and the ripe black berries. It is essential to cook the leaves in plenty of water and discard the first boiling, which reduces the solanine and solasodine alkaloids present in the plant. The green berries are toxic and must be avoided; the ripe black ones are safe in small quantities. In Puebla and Tlaxcala cuisine they are prepared in pork stews in tomato sauce, in broths with maize masa and guajillo chilli, and in battered fritters. In Oaxaca and Chiapas they are incorporated into moles and memelas. The plant should not be confused with belladonna or with other toxic Solanaceae of the countryside.

Cultural significance

Black nightshade forms part of the repertoire of quelites included in the Mexican gastronomic heritage recognised by UNESCO in 2010. It is an example of the traditional knowledge about using wild plants that distinguishes edible species from toxic ones, ancestral knowledge preserved by rural women and healers. In Mexican folk medicine, the plant has been used since pre-Hispanic times in infusions for skin problems, menstrual pains and inflammation. The FAO has highlighted the role of wild edible plants such as black nightshade in the complementary nutrition of rural communities of the global south. In Mexico, its gathering remains a seasonal activity in rural markets such as those of Tlaxco, Cuetzalan, Huauchinango and Tehuacán. Although it does not feature in fine dining with the same visibility as other quelites, its presence in the peasant cuisine of Puebla and Oaxaca makes it an element of regional identity and food sovereignty of Nahua, Totonac and Zapotec communities.

Frequently asked questions

What is the difference between black nightshade and other quelites?

Black nightshade belongs to the Solanaceae family, along with the tomato and the potato, while most Mexican quelites are from the families Amaranthaceae, Asteraceae or Portulacaceae. Its distinctive feature is producing edible black berries in addition to tender leaves. It requires more care in its preparation than other quelites because it contains alkaloids that are eliminated by proper cooking.

What does black nightshade taste like?

The cooked leaves have a mild, earthy and slightly bitter herbal flavour, comparable to that of chard or spinach with a more mineral undertone. The ripe berries are small, juicy and sweet, with a sour touch reminiscent of a ripe cherry tomato. It combines well with tomato, guajillo chilli, garlic, onion and maize masa in traditional highland preparations.

How is black nightshade served?

It is always prepared cooked: the leaves are boiled in salted water, drained and incorporated into stews with tomato and chilli, battered fritters with egg, broths with maize masa or memelas. In Oaxaca it is added to green moles and to the sauce of chichilos. The ripe berries are eaten fresh in small quantities or used in traditional salsas and jams in certain areas of Puebla.

Where does black nightshade come from?

It is native to the tropical and subtropical regions of the Americas, with a wide distribution from the southern United States to Argentina. In Mexico it is found in almost the whole country, with greater consumption in Puebla, Tlaxcala, Oaxaca, Veracruz, Chiapas and the State of Mexico. It grows wild during the rainy season among the maize and bean crops of the milpa system.