Lyre-leaf Rockcress - Arabidopsis lyrata
Arabis lyrata, Arabis kamchatica
State Rank Reason (see State Rank above)
Known from one 1952 collection near Mount Brown in Glacier National Park.
Lyre-leaf Rockcress is a short-lived perennial with 1 to several simple or branched stems, which are 1-3 dm high and arise from a simple or branched rootcrown. The mostly basal leaves, which are 1-6 cm long, have lobed, broadly lance-shaped blades narrowed to a petiole of equal length. The alternate stem leaves are sessile and few-lobed. Foliage is sparsely covered with long, stiff hairs. 3-20 erect, stalked flowers are borne in a compact inflorescence that expands as the fruits mature. Each flower has 4 glabrous sepals which are ca. 3 mm long, 4 white petals which are 5-8 mm long, 4 long stamens, and 2 short stamens. The glabrous, slightly compressed, linear capsules (siliques) are 2-4 cm long, ca. 1 mm wide, and are held erect.
Flowering and possibly fruiting in May.
Montane and lower subalpine sites. Exact habitat preferences in Montana uncertain.
Threats or Limiting Factors
STATE THREAT SCORE REASON
Threat impact not assigned because threats are not known (MTNHP Threat Assessment 2021).
- Additional ReferencesLegend: View Online Publication
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- Lesica, P., M.T. Lavin, and P.F. Stickney. 2012. Manual of Montana Vascular Plants. Fort Worth, TX: BRIT Press. viii + 771 p.