Two new Peruvian species of Brayopsis (Brassicaceae; Cruciferae), and a key to the species Author Al-Shehbaz, Ihsan A. Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, Missouri 63110, U. S. A. Author Cano, Asunción Laboratorio de Florística, Departamento de Dicotiledóneas, Museo de Historia Natural, Universidad Nacional Mayor de San Marcos (UNMSM), Av. Arenales 1256, Lima 11, Peru. & Instituto de Investigación de Ciencias Biológicas Antonio Raimondi (ICBAR), Facultad de Ciencias Biológicas, (UNMSM), Calle Germán Amézaga 375, Lima 1, Peru. Author Trinidad, Huber Laboratorio de Florística, Departamento de Dicotiledóneas, Museo de Historia Natural, Universidad Nacional Mayor de San Marcos (UNMSM), Av. Arenales 1256, Lima 11, Peru. Author Gonzáles, Paúl Laboratorio de Florística, Departamento de Dicotiledóneas, Museo de Historia Natural, Universidad Nacional Mayor de San Marcos (UNMSM), Av. Arenales 1256, Lima 11, Peru. Author Huamán, Elluz Laboratorio de Florística, Departamento de Dicotiledóneas, Museo de Historia Natural, Universidad Nacional Mayor de San Marcos (UNMSM), Av. Arenales 1256, Lima 11, Peru. text Phytotaxa 2018 2018-12-13 383 1 111 111 http://dx.doi.org/10.11646/phytotaxa.383.1.7 journal article 10.11646/phytotaxa.383.1.7 1179-3163 13725150 Brayopsis cuscoensis Al-Shehbaz, P. Gonzáles, A. Cano & Trinidad , sp. nov. Diagnosis:— Brayopsis cuscoensis is readily separated from the other species of the genus by being non-pulvinate with glabrous, oblong, torulose fruit, papery petioles 2 − 3 times longer than blade, and coarsely reticulate, subglobose to broadly ovoid seeds. Type : — PERU . Cusco : Prov. Espinar, Condoroma, 5 km del pueblo de Condoroma, 15°14 ʹ 34 ʺ S , 71°08 ʹ 28.33 ʺ W , 4850 m , 15 March 2018 , P . Gonzáles & E . Huamán 4290 ( holotype , USM-304080; isotype , MO-6835841). Figures 3 , 4 . FIGURE 3. Brayopsis cuscoensis A. Plant. B. Leaf. C. Fruit. D. Seeds. Drawn by Al-Shehbaz from the isotype (MO-6835841). Description: —Herbs perennial, deeply tap-rooted, not pulvinate; caudex simple or few branched, covered with petioles remains of previous years. Basal leaves densely rosulate; petiole persistent, 7 − 17 mm long, not ciliate, flattened and becoming papery, to 2.5 mm wide at base, 2 − 3 times longer than blade; blade orbicular to suborbicular, 4 − 6 × 4 − 7 mm , glabrous abaxially, sparsely puberulent adaxially with trichomes 0.05 − 0.25 mm long, margin entire, apex rounded. Fruiting pedicels 6 − 14( − 25) mm long, solitary from basal rosette, thick, glabrous. Flowers not seen; ovules 10 − 14 per ovary. Fruit oblong, terete, straight, 5 − 9 × 3 − 3.3 mm ; valves glabrous, torulose, with a distinct midvein; septum complete; gynophore absent; style obsolete or ca. 0.1 mm long. Seeds subglobose to broadly ovoid, 1.2 − 1.5 × 1 − 1.3 mm , prominently reticulate with units 0.02 − 0.05 mm across. Phenology: —Fruiting in March. Habitat: — Brayopsis cuscoensis grows on crioturbed soils above 4850 m . Etymology: —The species epithet cuscoensis is named after the Peruvian department Cusco . Distribution: —Endemic to the Peruvian department Cusco . Discussion: — Brayopsis cuscoensis differs from the other eight species of the genus by a combination of coarsely reticulate, subglobose to broadly ovoid seeds 1 − 1.3 mm wide and with reticulum units 0.02 − 0.05 mm across, oblong fruit 3 − 3.3 mm wide, and orbicular to broadly ovate, abaxially puberulent leaves with papery petioles 2 − 3 times longer than blade. By contrast, the other species have oblong to ovoid seeds 0.4 − 0.9 mm wide with smooth surface or reticulum units hardly reaching 0.01 mm across, linear or narrowly oblong fruit 1 − 2( − 2.5) mm wide, and variously shaped leaf blades (but never orbicular) with blade subequal or longer than petiole.