Narrow-leaved monardella – State Wildlife Action Plan

Narrow-leaved monardella is a fragrant, 15-30 cm tall subshrub with a woody base. The lorate to very narrowly elliptic leaves are often fascicled (bundled), spreading to reflexed, 10-13 mm long by 1.9-2.5 mm wide, and commonly conduplicate. The pale to grayish green leaves are punctate glandular, puberulent above and below, and sometimes glabrous or nearly so. The inflorescences are usually solitary, but are occasionally an open compound cyme, especially when there is abundant water and (or) nutrients available. The flowers are in terminal glomerules, with the densely clustered flowers on the primary stem being 16-18 mm wide and 8-11 mm wide on axillary stems. Inflorescence bracts are 7-8 mm by 3-4 mm, smaller than the calyces, straw to green in color with purple tinge, and elliptic to narrowly elliptic. The pedicels are 1.0-1.5 mm long; the flower calyx is 6-7 mm, green with the apex tinged purple. Corollas of M. angustifolia are 13-16 mm long, lavender in color, and rapidly deciduous after pollination. The fruits are an oblong nutlet 1.6-1.7 mm by 0.7-0.8 mm, brown to dark brown in color and mottled light and dark brown.

Overview

Species Common Name Narrow-leaved monardella
Species Scientific Name Monardella angustifolia
State Listing Status Threatened

Ecoregions

Northern Basin and Range

The Northern Basin and Range ecoregion covers the very large southeastern portion of the state, from Burns south to the Nevada border and from the Christmas Valley east to Idaho. It is largely a high elevation desert-like area dominated by sagebrush communities and habitats.

Special needs

Narrow-leaved monardella is endemic to ash tuff outcrops in southeastern Oregon. Found growing along steep slopes in sagebrush steppe and ash bed habitat within the Owyhee River watershed and Succor Creek basin.

Limiting factors

The major threat is invasive plants, which create competition for resources and increase the likelihood of fires and post-fire weed proliferation. Issues related to small population size are also threats.

Data gaps

Assess genetic diversity between Chalk Basin and Leslie Gulch populations. Conduct pollinator studies. Develop seed germination, propagation, and transplanting protocols.

Conservation actions

Monitor existing populations. Protect, maintain and restore existing habitat. Collect and bank seed as insurance against local extirpation or extinction and to use in ex-situ research.

Key reference or plan

Marshall, DA, and J Brown. 2023. 2023 listing status assessment for Monardella angustifolia (narrow-leaved monardella). Oregon Department of Agriculture, Salem, Oregon.