Erysimum capitatum (Dougl.) Greene

Western Wallflower

Erysimum capitatum plant

Family - Brassicaceae

Stems - Erect, to +25cm tall, from a taproot, erect, herbaceous, fistulose, appressed pubescent (with malpighian hairs).

Erysimum capitatum stemStem and nodes

Leaves - Alternate, short-petiolate at the base, sessile above. Margins with a few shallow teeth. Blades densely appressed pubescent, tapering at the base, acute, to +6cm long, -1cm broad, linear to linear-lanceolate.

Erysimum capitatum leavesLeaves

Erysimum capitatum leavesStem and leaves

Inflorescence - Terminal raceme. Pedicels to 5mm long in flower, slightly longer in fruit, erect, with pubescence as the stem.

Erysimum capitatum inflorescenceInflorescence

Flowers - Petals 4, clawed, distinct. Claw yellow, to +/-1cm long. Limb orange, sub-orbicular, to 9mm long, glabrous. Stamens 6, erect. Filaments greenish-white, glabrous, compressed, 1cm long. Anthers greenish, 2mm long. Ovary densely appressed pubescent (the hairs forked and arranged vertically), 1cm long. Style short, 1.1mm long. Stigma capitate. Sepals 4, erect, 9-10mm long, to 2mm broad, linear-oblong, gibbous at the base, glabrous internally, pubescent as the stem externally, light green, often slightly keeled. Siliques beaked, pubescent as the ovary, erect, mostly parallel to the axis of the inflorescence.

Erysimum capitatum calyxCalyx.

Erysimum capitatum flowersFlowers.

Erysimum capitatum flowersFlowers.

Flowering - April - July.

Habitat - Limestone bluffs, glades, rocky open ground.

Origin - Native to U.S.

Other info. - This biennial species is certainly the most showy of the genus in Missouri and indeed one of the showiest of all species. It can be found mainly in the north-central Ozark region and is mostly restricted to the habitats mentioned above. The plant would be a good garden subject and will grow from seed.

Photographs taken off Hwy 29, Guilford County, NC., 4-23-03 (DETenaglia); also at West Tyson County Park, St. Louis County, MO, 5-3-2015 (SRTurner).