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 a close relative of Psychotria carthagenensis (a.k.a. samiruka or amiruca) of Ecuador. 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. Description P. viridis is a perennial shrub that grows to a height of approximately . Its branches span a diameter of about Stems In the middle and lower parts of the stem, situated between the insertion points of the two opposite leaves there is a horizontal scar wide that extends between the leaves (or leaf scars) and sometimes also connects over the tops of these scars, and along the top side of this scar there is a dense, usually furry line of fine trichomes (i.e., plant hairs) usually long that are reddish brown when dried. This combination of features is diagnostic for many species in the genus Psychotria, though not for any individual species. These features distinguish Psychotria L. Subg. Psychotria; other subgenera of Psychotria lack the well developed reddish brown trichomes inserted above the stipule scars. 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. Stipules Stipules are leafy structures that cover and protect the young developing leaves. They may persist or fall off, leaving scars on the stem. The stipules in P. viridis are produced in pairs and their form is distinctive. They are by , elliptic in outline, sharply angled at the apex, papery to membranaceous in texture, ciliate (i.e., fringed) along the upper margins, and longitudinally flanged or winged along the middle. Leaves Leaves are opposite in arrangement (i.e., produced in pairs along the stems), generally by , 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). The leaves are borne on petioles (i.e., leaf stalks) generally long. When dry, the leaves of Psychotria viridis usually are gray