Lenspod Whitetop - Lepidium chalepense
Other Names:
Chalapra Hoarycress, Lens-pod Hoarycress,
Cardaria draba ssp. chalepensis, Cardaria chalepensis, Cardaria draba ssp. chalapensis
Rhizomatous perennial. Stems erect, simple, 20–60 cm. Basal leaves oblong to oblanceolate, dentate, 3–12 cm long. Stem leaves auriculate clasping. Vestiture pubescent with simple hairs below, glabrous in the inflorescence. Flowers white; petals 3–4 mm long; stamens 6. Fruits compressed globose, glabrous, 2–5 mm long, not notched; style 1–2 mm long, pedicels 8–15 mm long, glabrous (
Lesica et al. 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).
There are many white-flowered species in the Mustard Family, both native and exotic. It is recommended that identifications be made using a plant manual designed for Montana. Mustards have flowers with 4 sepals, 4 petals, and 6 stamens (4 long and 2 short) among other characteristics.
Lenspod Whitetop –
Lepidium chalepense, exotic:
* White-flowered plants that grow from creeping roots (rhizomes) and have mature silicles (fruits) that are not notched at their tip.
* Silicles are glabrous (lack hairs), partially inflated and round (compressed-globose), not cordate (is pointed to its stem), and topped with a style 1-2 mm long. Silicle stems (pedicels) are 8-15 mm long.
* Stem leaves are auriculate (lobed like an arrow) and clasping around the stem.
Globe-podded Whitetop –
Lepidium appelianum, exotic:
* White-flowered plants that grow from creeping roots (rhizomes) and have mature silicles (fruits) that are not notched at their tip.
* Silicles are pubescent (have hairs), inflated (globe-shaped), and with a short style of 0.4-1.0 mm long. Silicle stems (pedicels) are 4-11 mm long.
* Stem leaves are auriculate (lobed like an arrow) and clasping around the stem.
Perennial Pepperweed –
Lepidium latifolium, exotic and Noxious:
* White-flowered plants that grow from creeping roots (rhizomes) and have mature silicles (fruits) that are not notched at their tip.
* Silicles are glabrous or sparsely pilose (long soft hairs) with a very short style of 0.1 mm long or less. Silicle stems (pedicels) are 2-5 mm long.
* Stem leaves are sessile, but do not clasp around the stem.
Whitetop –
Lepidium draba, exotic and Noxious:
* White-flowered plants that grow from creeping roots (rhizomes) and have mature silicles (fruits) that are not notched at their tip.
* Silicles are glabrous (lack hairs), flattened, and their base is cordate (heart-shaped or indented). Silicles are tipped with a style of 1-1.5 mm long. Silicle stems (pedicels) are 5-12 mm long.
* Stem leaves are auriculate (lobed like an arrow) and clasping around the stem.
The other Montana
Lepidium species (using MTNHP preferred name) have mature silicles with a notch of at least 0.1 mm deep at their top
and are not rhizomatous.
Hoary False-alyssum –
Berteroa incana, exotic and Noxious:
* White-flowered, annual plants that grow from taproots and have mature silicles (fruits) that are not notched at their tip.
* Each of the 4 petals are notched, making the flower appear 8-petaled.
* Plants have star-shaped hairs; whereas,
Lepidium species have simple hairs or none.
* Stem leaves are widest near their tip (oblanceolate), sessile on the stem, and point upwards.
Field Pennycress –
Thlaspi arvense, exotic:
* Easily differentiated if in fruit and easily confused with other species if only of leaves.
* White-flowered, annual plants that grow from taproots and have mature silicles (fruits) that are large, deeply notched at their tip, flat, and with wide wings, resembling a penny.
* Lower stem leaves have petioles. Upper stem leaves are sessile, clasping, auriculate (lobed like an arrow), and with smooth to toothed margins.
Common Yarrow –
Achillea millifolium, native and desirable:
* Member of the Aster/Sunflower Family.
* Bright-white flowers arranged closely in a flat-topped inflorescence.
* Leaves are 2-3 times pinnately dissected, appearing fern-like or bushy like a squirrel’s tail.
Sources: Jacobs and Mangold 2007; FNA 2010; Graves-Medley and Mangold 2011; Lesica et al. 2012.
Based on the Montana Natural Heritage Program's latest
predicted habitat suitability model
| Total species' range in Montana |
381,296 km2 |
(100% of Montana) |
Area predicted to have
some level of suitable habitat |
235,659 km2 |
(62% of Montana) |
Stewardship responsibility for the predicted area of suitable habitat can be broken down as follows
| |
Total Suitable |
Optimal Suitability |
Moderate Suitability |
Low Suitability |
| Federal |
23% |
<1% |
2% |
21% |
| State |
6% |
<1% |
1% |
5% |
| Local |
<1% |
<1% |
<1% |
<1% |
| Conservation Lands/Easements |
3% |
<1% |
1% |
2% |
| Private/Tribal/Unknown |
66% |
<1% |
12% |
54% |
See the Habitat Suitability for Biodiversity task in Map Viewer
for a more detailed look at stewardship responsibilities within a variety of local jurisdictions.
