Ourisia ruellioides

Ourisia ruellioides plants are perennial, ascending to erect herbs. The short stems are 1.9–4.3 mm wide, and glabrous (hairless) or hairy. Leaves are opposite, tightly clustered, petiolate, 6.2–116.1 mm long by 4.4–71.3 mm wide (length: width ratio 1.2–2.0:1). Leaf petioles are 6.3–250.0 mm long and usually glabrous or hairy with long non-glandular hairs. Leaf blades are usually narrowly ovate, ovate or broadly ovate, widest below the middle, usually with an acute apex, truncate or cordate base, and serrate edges. The both surfaces of the leaf are usually glabrous or with a few long non-glandular hairs, and the lower surface is also punctate. Inflorescences are erect racemes, up to 44 cm long. Each inflorescence has 1–6 flowering nodes with one or two flowers and 2 bracts in each node. The bracts are similar to the leaves but smaller, 2.3–3.5 mm long and 0.8–1.6 mm wide, and sessile. The flowers are borne on a pedicel that is up to 62.5 mm long and usually glabrous, or sometimes with a few short or long non-glandular or sessile glandular hairs. The calyx is 5.0–9.1 mm long, irregular, with 2 lobes divided to the base of the calyx and 3 lobes divided one-sixth to one-half the length of the calyx, and usually glabrous but ciliate. …

Ourisia ruellioides is endemic to the Andes mountains of southern Argentina and Chile from 34°S to 56°S latitude. Spanning 22 degrees of latitude, it is the most widespread and common species of Ourisia. In Argentina it is found from Neuquén, Río Negro, Chubut, Santa Cruz and Tierra del Fuego, including several national parks, and the Chilean regions of O'Higgins, Maule, Ñuble, Biobío, Araucanía, Los Ríos, Los Lagos, Aysén and Magallanes. O. ruellioidies can be found from 0 to 2600 m above sea level in wet, rocky, shady habitats, including in Nothofagus forests, often in or near running water. It is one of three species of Ourisia to reach Tierra del Fuego (together with O. fuegiana and O. breviflora subsp. breviflora), where it is common in two of the four main vegetational zones, i.e. evergreen forest and deciduous forest, and found on several islands including Isla de los Estados.