1. Maca (Lepidium meyenii Walpers * - Lepidium peruvianum Chacón *) Classification

Superdivision: Spermatophyta – Seed plants
Division: Magnoliophyta (Flowering plants)
Class: Magnoliopsida (Dicotyledons)
Subclass: Dilleniidae
Order: Capparales
Family: Cruciferae = Brassicaceae (Crucifer or Mustard Family)
Tribe: Lepidieae
Section: Monoploca
Genus: Lepidium L. – pepperweed
Species: Lepidium meyenii described by Gerhard Walpers in Nov. Act. Nat. Leopold. Carol. 19, Suppl. 1 (1843) 249.
Synonyms:

• Lepidium peruvianum Chacón *
• Lepidium weddellii
• Lepidium affine
• Lepidium gelidum

Related Species:

• Lepidium sativum
• Lepidium meyenii Walp. *
• Lepidium bipinnatifidum Desvaux
• Lepidium kalenbornii C. L. Hitchcock
• Lepidium chichicara Desvaux

* Observation: South American species Lepidium meyenii Walp. was first described by Gerhard Walpers in 1843. Although there are extensive taxonomic treatments of the Lepidium species of Australia (Hewson 1982) and North America (Al-Shehbaz 1986a, 1986b) as well as a general monograph on the genus (Thellung 1906), information is scarce on the species endemic to South America, and in particular about the Andean species of Lepidium, which belong mostly to the sections Dileptium and Monoploca (Thellung 1906). Hence, taxonomy of Andean Lepidium species is not definitive and is susceptible to change.

Additionally, the original collections of Lepidium meyenii Walp. were done outside the present range of distribution of cultivated Lepidium, namely Puno in Peru. Although it is believed that in Inca times Lepidium sp. was cultivated in Puno, there is no evidence of this crop being cultivated there at the present time.

Later, other accessions collected in Bolivia and Argentina were also classified as Lepidium meyenii Walp. After superficial morphological inspection, however, no resemblance to cultivated Andean Lepidium can be seen in these early herbarium specimens, which in many cases are not in optimal conditions.

Recently, Chacón de Popovici (1990), suggested that the cultivated ‘maca’ of today, –the Andean cultivated species of Lepidium– is not Lepidium meyenii Walp. but a newer species. Hence, she proposed to create the name Lepidium peruvianum Chacón sp. nov., based on comparative studies of the botanical characteristics, and in particular, on the histochemical observations of the hypocotyl, which is the main distinguishing feature of this new species, and on morphological observations and comparative analysis of herbarium specimens in Germany and the United States of America and various specimens collected since 1960 in the district of San Juan de la Jarpa, in Huancayo province.

Taking all of these into account, the proposal of the new name for the cultivated species seems reasonable, although further taxonomic research is required to solve this problem. While most maca sold in commerce today still refers to the Lepidium meyenii Walp. name, economic botanists believe most is Lepidium peruvianum Chacón. Until now, there is no consensus among the authorities; while some of them agree with Chacón, others consider Lepidium peruvianum Chacón just a synonym of the species Lepidium meyenii Walp.

Common Names: “maca”, “Peruvian ginseng”, “pepper grass”, “pepper weed”, “mace”. Castilian/Spanish: Peru “maca”, “maka”. Quechua: “maca”, “maca-maca”, “maka”. Others: "maino", "maka", "ayak chichira", "ayak willku".