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Montana Field Guide

Montana Field Guides

Dense-leaf Draba - Draba densifolia

Species of Concern

Global Rank: G5
State Rank: S2
* (see State Rank Reason below)

Agency Status
USFWS:
USFS:
BLM:
MNPS Threat Rank: 2
C-value:

External Links






State Rank Reason (see State Rank above)
Draba densifolia is distributed in the western half of the state in four moderate to large populations, six small occurrences and nine historical or poorly documented occurrences. Occupied habitats are at moderate to high elevation which help to minimize disturbance to some of the populations. However, livestock grazing, invasive weeds and off-road ATV use impact some populations.
 
General Description
Dense-leaf Draba is a mat-forming perennial with leaf rosettes at the ends of numerous rootcrown branches, which are clothed with old leaf bases. The leafless stems are 3-15 mm high and arise from some of the rosettes. The fleshy, narrowly lance-shaped leaves are 2-12 mm long and have a prominent midvein and straight, unbranched hairs on the entire margins but are otherwise mostly glabrous. 3-15 stalked flowers are borne at the tops of the stems. Each flower has 4 separate sepals, 4 separate, yellow petals that are 2-6 mm long, and 4 long and 2 short stamens. The style is 0.5-1.0 mm long. The hairy, egg-shaped capsules are 2-7 mm long and are borne on erect or ascending stalks.

Phenology
Flowering from May-July, depending on elevation.

Diagnostic Characteristics
There are many similar-appearing, yellow-flowered, mat-forming species of Draba in our area. A technical manual and hand lens or microscope is required for positive identification. This species can be dintinquished from D. oligosperma by the simple hairs. Draba daviesiae also has glabrous leaves, except for simple hairs on the margins, but it has glabrous fruits.

Species Range
Present
 


Range Comments
AK to AB south to CA, UT and WY (Lesica 2012. Manual of Montana Vascular Plants. BRIT Press. Fort Worth, TX).

Summary of Observations Submitted for Montana
Number of Observations: 22

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density

Recency

 

(Observations spanning multiple months or years are excluded from time charts)



Habitat
Gravelly, open soil of rocky slopes and exposed ridges in the montane to alpine zones.

Ecological Systems Associated with this Species

References
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Citation for data on this website:
Dense-leaf Draba — Draba densifolia.  Montana Field Guide.  .  Retrieved on , from