Psychotria viridis, also known as chacruna, chacrona, or chaqruy in the Quechua languages, is a perennial, shrubby flowering plant in the coffee family Rubiaceae.

It is commonly used as an ingredient of ayahuasca, a decoction with a long history of its entheogenic (connecting to spirit) use and its status as a "plant teacher" among the Indigenous peoples of the Amazon rainforest.

On the upper stems of P. viridis these features are obscured by a stipule (see below), which covers the trichomes; the scar actually marks the point where this structure has fallen off.

[citation needed] Stipules are leafy structures that cover and protect the young developing leaves.

[citation needed] Leaves are opposite in arrangement (i.e., produced in pairs along the stems), generally 5–15 cm (2.0–5.9 in) by 2–6 cm (0.79–2.36 in), in outline generally elliptic or often widest above the middle, usually sharply angled at base and apex, papery in texture, overall smooth or infrequently with microscopic plant hairs on the lower surface, have 5–10 pairs of secondary veins, and on the lower surface usually have foveolae (see next item).

These mites apparently often are symbiotic with the plant, taking shelter in these structures and eating fungi and herbivorous invertebrates that can damage the leaf.

The foveolae (also called domatia) are distinctive for Psychotria viridis and a few related species: They are generally 1.5–5 mm (0.059–0.197 in) long and 0.5–1 mm (0.020–0.039 in) wide at the top, conical and tapered to a closed base, open and truncate or variously ornamented at the top, and situated along the sides of the central vein with the opening usually near a secondary vein .

[7] The Machiguenga people of Peru use juice from the leaves as eye drops to treat migraine headaches.

The mechanism of action is via the monoamine oxidase inhibitor (MAOI) present in Banisteriopsis caapi, which allows ayahuasca to be effective in oral doses (unlike smoking DMT crystals which requires no conditioning partner substance).

This use was made legal in Brazil in 1992 when B. caapi, P. viridis, and the ayahuasca tea were exempted from the list of illicit drugs.

[8] Vegetalistas, healers in the Amazon regions of Peru, Ecuador, and Colombia, recognize different sub-varieties of Psychotria viridis, based on the location of glands on the back of the leaves.

Darren Williams has now created over 150 new cultivars by intercrossing P. viridis accessions, backcrossing and sib crossing, resulting in various new genotypes, given the prefix DW, eg.