Yellowstone draba – Draba incerta

Alaska Wildflowers | Yellow

The yellow flowers of Yellowstone draba (Draba incerta) in Denali National Park.

Yellowstone draba

Draba incerta

Common Names

Yellowstone draba
whitlow grass
Yellowstone whitlowgrass

Synonyms

Draba exalata
Draba laevicapsula
Draba peasei
D. incerta var. incerta
D. incerta var. peasei

Subspecies

none

Genus: Draba (Draves, whitlowgrass)
Family: Brassicaceae
Order: Brassicales
full classification

Duration – Growth Habit

Perennial – Forb/herb



Identification and Information

The Yellowstone draba, or Draba incerta, is a perennial herb that is tufted in nature, growing from a taproot with a typically extensively branched stem base. The plant’s stems are erect, ranging in height from 2 to 20 cm (0.8 to 8 inches), and are covered with starlike hairs.

Close-up image of the rosette of basal leaves with starlike hairs
Close-up of the hair on the basal leaves of D. incerta

The plant is often cushion-like (pulvinate), and the caudex (the plant’s stem base) is branched, usually densely covered with persistent leaf remains. The basal leaves of D. incerta are narrowly oblanceolate, ranging from 0.7 to 1.5 cm long (0.3 to 0.6 inches) and 1 to 4 mm wide. They are hairy, covered with stalked, 4-rayed, starlike hairs that are again branched. The leaf margins are fringed with hair, and the midribs are somewhat persistent, remaining as threadlike processes. The midvein is usually obscure on the underside of the leaf. Notably, stem leaves are absent except on new shoots.

Draba incerta produces a raceme of 3 to 15 yellow flowers. The four petals of these flowers are 4 to 5.5 mm long (0.16 to 0.22 inches), and the sepals are 2.5 to 3.5 mm long (0.1 to 0.14 inches) and sparsely covered with soft hair. The anthers of the flowers are well-formed and ovate, a key characteristic distinguishing D. incerta from similar species like D. oligosperma.

The fruit of D. incerta is a type of silicle (a small silique, which is a type of fruit specific to the Brassicaceae family), 6-10 mm long (0.24 to 0.4 inches) and 2.5-3.5 mm wide (0.1 to 0.14 inches). These silicles are lanceolate to egg-shaped, can be hairy to nearly glabrous, and are generally flat. The lowest fruiting stalks, or pedicels, are 4-18 mm long (approximately 0.16 to 0.7 inches), usually twice the length of the silicles, ascending, and starlike-hairy. The styles of the silicles are 0.4-1 mm long (0.02 to 0.04 inches), and each fruit contains between 8-14 seeds, each 1.2-1.5 mm long (0.05 to 0.06 inches).

Confusion With Other Drabas

Numerous yellow drabas look incredibly similar and can be incredibly difficult to distinguish. Flora of North America discusses one of these, alpine draba (drabas alpina), which was previously identified in Alaska, but is now thought to be confined to the eastern provinces in Canada in North America. According to FNA, “The name D. alpina was so misapplied that it was used for any circumpolar or alpine, scapose, yellow-flowered, perennial Draba.” Another draba that may be found in Alaska, D. oligosperma has flowers that look almost identical to D. incerta, but the leaves aren’t as hairy and appear flatter or less succulent.

Uses

For information only (typically historical) – I take no responsibility for adverse effects from the use of any plant.

The Blackfoot tribe used an infusion of the roots of D. incerta as a remedy for nosebleeds. It was also utilized for its abortifacient properties, meaning it was used to induce abortions. I found no information regarding its use as a food source.

While specific information about the potential toxicity of D. incerta and many other Draba species might not be readily available, some plants in the Brassicaceae family (to which Draba belongs) are known to contain glucosinolates. Glucosinolates are a group of compounds that can have various effects on human health. They are usually not harmful in small amounts; some can even have health benefits. However, they can be dangerous in larger quantities, potentially causing gastrointestinal upset or thyroid dysfunction.

Glucosinolates are significant plant compounds found mainly in the Brassicaceae family, which includes common vegetables like broccoli, cabbage, and cauliflower. When consumed without processing (like cooking), these compounds are broken down by the enzyme myrosinase into various metabolites that can be harmful in large quantities. However, when these plants are cooked, myrosinase is inactivated, and glucosinolates can be partially absorbed in their original form through the gut lining.


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Distribution and Habitat

Yellowstone draba is widely distributed only in North America, commonly found throughout British Columbia, east of the Coast-Cascade Mountains. Its range extends northward to Alaska and the Yukon, eastward to Alberta, and southward to Washington, Idaho, Montana, and Wyoming. There are also disjunct populations in Quebec. This plant is adapted to a variety of elevations, ranging from sea level in Alaska to high altitudes up to 3300 meters (11,000 feet).

It is well-adapted to rugged, rocky, and often harsh environments. It thrives in a variety of alpine and subalpine habitats, including dry meadows, cliffs, fellfields (areas of loose, unstable rock debris), and scree slopes. It’s typically found in the upper montane, subalpine, and alpine zones. The plant grows in various soil moisture regimes, from very dry to moderately moist conditions, and is most commonly found in nutrient regime class B, which signifies moderate nutrient conditions.

Classification

RankScientific Name (Common Name)
KingdomPlantae (plantes, Planta, Vegetal, plants)
   SubkingdomViridiplantae (green plants)
      InfrakingdomStreptophyta (land plants)
         SuperdivisionEmbryophyta 
            DivisionTracheophyta (vascular plants, tracheophytes)
               SubdivisionSpermatophytina (spermatophytes, seed plants, phanérogames)
                  ClassMagnoliopsida 
                     SuperorderRosanae 
                        OrderBrassicales 
                           FamilyBrassicaceae (mustards, moutardes, crucifers)
                              GenusDraba L. (draves, whitlowgrass)
                                 SpeciesDraba incerta Payson (Yellowstone draba)

References and Further Reading

Guidebook

Field Guide to Alaskan Wildflowers, Pratt, Verna E. pg. 41

Classification and Taxonomy

Draba incerta Payson Taxonomic Serial No.: 22885, ITIS Database

Uses

Draba incerta Payson, Native American Ethnobotony Database

Prieto MA, López CJ, Simal-Gandara J. Glucosinolates: Molecular structure, breakdown, genetic, bioavailability, properties and healthy and adverse effects. Adv Food Nutr Res. 2019;90:305-350. doi: 10.1016/bs.afnr.2019.02.008. Epub 2019 Mar 25. PMID: 31445598.

Map and Distribution

Draba incerta Payson Published in: Payson, E.B. Amer. J. Bot. 4: 261. (1917)., GBIF Database

Draba incerta Yellowstone Whitlow-grass, NatureServe Explorer

Description and Information

D. incerta Payson Amer. J. Bot. 4: 261. 1917., Flora of North America

D. incerta Payson Yellowstone draba (Yellowstone whitlow-grass), Flora of British Columbia

 

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