Lepidium latifolium L.

Perennial Pepper Grass

Lepidium_latifolium_plant.jpg
STATS

Introduced
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© SRTurner

Family - Brassicaceae

Habit - Rhizomatous perennial forb.

Stem - Ascending to erect, to 1.2 m, mostly unbranched, glabrous or nearly so.

Lepidium_latifolium_stem.jpg Stem and node

© SRTurner

Leaves - Basal and alternate, simple, 1-30 cm long, linear to oblanceolate or elliptic in outline, the base not clasping, glabrous, the margins entire or finely toothed, the lower and middle ones petiolate, the upper leaves progressively reduced and sessile.

Lepidium_latifolium_basals.jpg Basal leaves.

© SRTurner

Lepidium_latifolium_leaf1a.jpg Lower leaf.

© SRTurner

Lepidium_latifolium_leaves.jpg Stem and leaves.

© SRTurner

Lepidium_latifolium_leaf1.jpg Stem leaf, adaxial.

© SRTurner

Lepidium_latifolium_leaf2.jpg Stem leaf, abaxial.

© SRTurner

Inflorescence - Panicles, typically crowded with numerous flowers. Bracts absent.

Lepidium_latifolium_inflorescence.jpg Inflorescence.

© SRTurner

Flowers - Sepals 0.8-1.5 mm long, broadly elliptic to ovate. Petals 1.5-2.5 mm long, white. Stamens 6. Styles absent.

Lepidium_latifolium_flowers.jpg Sepals and flowers.

© SRTurner

Lepidium_latifolium_corollas.jpg Corollas.

© SRTurner

Fruits - Silicles 1.8-2.2 mm long, broadly ovate to nearly circular in outline, the tip rounded, not notched or winged, flattened, sparsely hairy or glabrous. Seeds 1.0-1.3 mm long, oblong-elliptic in outline, not winged, the surface with a very fine, netlike or honeycomb-like pattern of ridges and pits, brownish orange.

Lepidium_latifolium_fruits.jpg Fruits.

© SRTurner

Flowering - June - August

Habitat - Open disturbed areas.

Origin - Native to Eurasia.

Lookalikes - Other species of Lepidium, particularly L. chalepense and L. draba.

Other info. - This species is very rare in Missouri, known from only one site on the far western edge of the state. It is far more common to our west, and in fact is considered a noxious weed in many western states, where the above photographs were taken. The plant is reasonably easy to identify; it is the only Missouri species of Lepidium having both 6 stamens per flower and leaves which do not clasp the stem.

Photographs taken in Grandstaff Canyon, Grand County, UT, 08-06-2017, Fort Morgan, Morgan County, CO, 06-19-2018, Dinosaur National Monument, Uintah County, UT, 06-27-2018, and along a roadside in Granite County, Montana, 8-15-2019 (SRTurner).