1. Exhalimolobos arabioides (Muschler) Al-Shehbaz & C. D. Bailey, Syst. Bot. 32: 149. 2007; Greggia arabioides Muschler, Bot. Jahrb. Syst. 40: 274. 1908. TYPE. Peru, Ancash, below Hacienda Cajomba, between Samanco and Garaz, 3000-3500 m, A. Weberabuer 3157 (lectotype designated by Bailey et al. (2007), B!).
Halimolobos weddellii O. E. Schulz var. herrerae O. E. Schulz, Notizbl. Bot. Gart. Berlin-Dahlem 11: 391. 1932; Sisymbrium hispidulum (de Candolle) Triana and Planchon var. herrerae (O. E. Schulz) J. F. Macbride, Publ. Field Mus. Nat. Hist., Bot. Ser. 8, 2(3): 977. 1938; Halimolobos hispidulus (de Candolle) O. E. Schulz var. herrerae (O. E. Schulz) Rollins, Contr. Dudley Herb. 3: 252. 1943. TYPE: Peru, Valle de Urubamba, alrededores del pueblo de Zucay, 3000 m, Feb 1929, F. L. Herrera 2245 (holotype, B).
Herbs annual, densely pubescent throughout. Stems erect, often single from base, branched above, 4-12 dm tall, setose with rigid and simple or coarsely 2-rayed trichomes to 1.8 mm, these mixed with much smaller 2-5-rayed ones. Basal leaves not rosulate, soon withered; middle cauline leaves sessile, auriculate to amplexicaul, oblong to lanceolate, (2-)3-9(-12) ´ 1-2.5(-3.5) cm, pubescent with 4-8-rayed trichomes 0.2-0.4 mm, these mixed with simple or 2-rayed ones to 1.2 mm. Racemes elongated considerably in fruit; fruiting pedicels horizontal to recurved or slightly reflexed, pubescent, 9-20 mm. Sepals oblong, green, pubescent, 3-4.5 ´ 1.2-1.6 mm; petals white or creamy white, spatulate, 5-6.5 ´ 1.5-2 mm; filaments 3.5-4.7 mm; anthers oblong, 0.8-1 mm; ovules 90-184 per ovary. Fruits oblong to oblong-linear, (0.7-)1.5-2.7 cm ´ 2.5-3 mm; valves moderately pubescent with subsessile trichomes; style (1-)1.5-2.5 mm. Seeds oblong, biseriate or appearing multiseriate, (0.65-)0.75-0.9(-1) ´ (0.45-)0.5-0.6 mm.
Flowering: Dec-May.
Habitat: Roadside hedges along fields, brushy stream banks.
Elevation: 2800-3700 m.