Sp. Pl. 2: 669. 1753.


Gen. Pl. ed. 5, 300. 1754.

Common names: Hill-mustard
Etymology: Greek and Latin bunias, a kind of common mustard or turnip
Treatment appears in FNA Volume 7. Treatment on page 444. Mentioned on page 224, 227, 236, 241.

Plants not scapose; glabrous or sparsely to densely pilose (multicellular glandular tubercles or papillae present throughout, except flowers). Stems erect, often branched (many) distally. Leaves basal and cauline; petiolate, sessile, or subsessile; basal not rosulate [rosulate], petiolate, blade margins entire, pinnatifid, or lyrate; cauline sessile (subsessile distally), blade (base cuneate, attenuate), margins dentate or entire. Racemes (corymbose or paniculate), considerably elongated in fruit. Fruiting pedicels divaricate, slender. Flowers: sepals (yellowish green), oblong, (margins membranous), (glabrous, [pubescent or glandular]); petals obovate, (longer than sepals), claw distinct or absent, (apex obtuse to emarginate); stamens strongly tetradynamous; filaments (yellowish), not dilated basally [dilated]; anthers oblong [ovate], (apex obtuse); nectar glands confluent, subtending bases of stamens, median glands present. Fruits nutletlike, sessile, (readily detached from pedicel), oblong, ovoid, or subglobose, smooth, terete, 4-angled, or with 4 cristate wings, (1–4-loculed), (woody); valves (not distinct) not veined, glabrous; replum not distinct; septum subwoody or absent; ovules 2–4 per ovary; style obsolete or distinct, (slender, filiform or subconical); stigma capitate. Seeds plump [flattened], not winged, subglobose to ovoid [oblong]; seed coat (smooth), not mucilaginous when wetted; cotyledons spirolobal. x = 7.


Introduced; Europe, Asia, n Africa.


Species 2 (2 in the flora).

Bunias erucago and B. orientalis have the same chromosome number; the former has only about 0.8-fold of the DNA amount of B. orientalis (J. Greilhuber and R. Obermayer 1999). Although both species are widespread weeds in Europe, they have not spread much in North America.


1 Fruits 4-winged, 4-loculed, (0.8-)0.9-1.3(-1.4) cm; seeds 3 or 4; petals (8-)10-13 mm; styles 3.5-5(-6) mm. Bunias erucago
1 Fruits not winged, 1- or 2-loculed, (0.5-)0.6-0.7(-0.8) cm; seeds 1 or 2; petals (4-)4.5-7(-8) mm; styles obsolete or, rarely, to 1 mm. Bunias orientalis