Remarkable discoveries in the long-neglected and Peruvian-endemic genus Machaerophorus (Brassicaceae) 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; Author Manchego, Marco Antonio Cueva Instituto de Investigación de Ciencias Biológicas Antonio Raimondi (ICBAR), Facultad de Ciencias Biológicas, (UNMSM), Calle Germán Amezaga 375, Lima 1, Peru. Author Salariato, Diego L. Instituto de Botánica Darwinion (CONICET-ANCEFN), Labardén 200, Casilla de Correo 22, B 1642 HYD, San Isidro, Buenos Aires, Argentina. text Phytotaxa 2018 2018-07-13 360 2 114 124 http://dx.doi.org/10.11646/phytotaxa.360.2.3 journal article 10.11646/phytotaxa.360.2.3 1179-3163 Machaerophorus Schlechtendal (1857: 469) . Herbs suffrutescent perennial, or subshrubs, tomentose, becoming puberulent or glabrescent with age. Trichomes simple and branched, crisped, flattened, forming floccose-arachnoid cover on young branches. Multicellular glands absent. Stems erect to ascending, branched, flexuous, woody below, leafy, unarmed. Basal leaves not developed; cauline leaves petiolate, not auriculate at base, finely pinnatisect into narrowly linear lobes, usually grooved abaxially and densely pubescent along groves, fleshy, entire. Racemes ebracteate, many flowered, lax, elongated considerably in fruit; rachis strongly flexuous; mature flower buds narrowly oblong; fruiting pedicels ascending to divaricate, straight or slightly curved, sometimes secund, persistent. Sepals linear-oblong, free, deciduous, erect, equal, base of lateral pair not saccate; petals yellow or white, erect at claw and with flaring blade, longer than sepals; blade ovate to oblong or linear, apex obtuse to acute; claw strongly differentiated, longer than sepals, glabrous, unappendaged, entire; stamens 6, slightly exserted, erect, tetradynamous; filaments wingless, unappendaged, glabrous, free; anthers linear, not apiculate; nectar glands 2, lateral, V-shaped, with a lateral arm on each side, subtending bases of lateral stamens; median glands absent; ovules 24–70 per ovary; placentation parietal. Fruit dehiscent, capsular siliques, linear to oblong-lanceolate or lanceolate, terete or strongly latiseptate, not inflated, unsegmented; valves papery, obscurely veined, glabrous or puberulent, not keeled, smooth or torulose, wingless, unappendaged; gynophore absent or obsolete, rarely to 0.5 mm long; replum rounded, visible; septum complete, usually wrinkled between seeds, not veined; style obsolete or 0.5–6 mm long, persistent; stigma capitate or subconical, distinctly wider than style, unappendaged, strongly 2-lobed, the lobes opposite replum, connivent, not decurrent, densely papillate and stigma appearing entire. Seeds uniseriate or biseriate, margined or apiculate, wingless, oblong or ovate, plump or slightly flattened; seed coat minutely reticulate, mucilaginous when wetted; cotyledons incumbent. A genus of three species endemic to southern Peru .