Braya humilis subsp. humilis

Illustrated
Synonyms: Arabidopsis novae-angliae (Rydberg) Britton Braya humilis var. abbei (Böcher) B. Boivin Braya humilis subsp. arctica (Rydberg) Hultén Braya humilis var. arctica (Böcher) B. Boivin Braya humilis var. interior (Böcher) B. Boivin Braya humilis var. laurentiana (Böcher) B. Boivin Braya humilis var. leiocarpa (Trautvetter) Fernald Braya humilis var. novae-angliae (Rydberg) Fernald Braya humilis subsp. richardsonii Rollins Braya humilis subsp. ventosa Böcher Braya humilis var. ventosa (Rollins) B. Boivin Braya intermedia Braya novae-angliae Braya novae-angliae subsp. abbei (Rollins) Böcher Braya novae-angliae var. interior Böcher Braya novae-angliae var. laurentiana Böcher Braya novae-angliae subsp. ventosa Böcher Braya richardsonii Pilosella novae-angliae Pilosella richardsonii Torularia humilis subsp. arctica
Treatment appears in FNA Volume 7. Treatment on page 549. Mentioned on page 550.

Stems ascending to erect, branched or unbranched, 0.4–3.3 dm, sparsely to moderately pubescent. Leaves: blade margins sinuate-dentate, shallowly pinnatifid, or entire, surfaces moderately pubescent. Flowers: petals white, pink, or purple, 2.5–6.9(–7.5) × (0.7–)0.9–4(–4.2) mm. Fruits usually fertile and fully developed, somewhat torulose, 0.6–1.2(–1.3) mm wide; septum not fenestrate or split longitudinally. 2n = 28, 42, 56, 70.


Phenology: Flowering May–Jul.
Habitat: Sandy, gravelly soil along streams, lakeshores, roadsides, moraines, open stony slopes, dolomite cliffs and slopes, limestone ledges, solifluction soils
Elevation: 0-4000 m

Distribution

V7 875-distribution-map.gif

Greenland, Alta., B.C., Man., Nfld. and Labr. (Nfld.), N.W.T., Nunavut, Ont., Que., Yukon, Alaska, Colo., Mich., Mont., Vt., Wyo., e, c Asia.

Discussion

Subspecies humilis is extremely variable morphologically. In a general way, morphological form correlates with ploidy level, e.g., tetraploids, octoploids, and decaploids tend to be short in stature with small leaves. Hexaploids are less predictable. They range from short plants with small leaves to large, robust, multi-branched plants with large, pinnatifid leaves. Attempting to segregate most morphological forms of Braya humilis into logical infraspecific taxa is an exercise in futility. Populations that appear distinctive in the field almost always blur imperceptibly into the larger subsp. humilis continuum when compared with other populations from across the range of distribution. Subspecies humilis is broadly distributed on calcareous substrates in arctic, subarctic, alpine, and boreal regions of North America and Asia.

Selected References

None.

Lower Taxa

None.
James G. Harris +
(C. A. Meyer) B. L. Robinson +
Sisymbrium humile +
Greenland +, Alta. +, B.C. +, Man. +, Nfld. and Labr. (Nfld.) +, N.W.T. +, Nunavut +, Ont. +, Que. +, Yukon +, Alaska +, Colo. +, Mich. +, Mont. +, Vt. +, Wyo. +, e +  and c Asia. +
0-4000 m +
Sandy, gravelly soil along streams, lakeshores, roadsides, moraines, open stony slopes, dolomite cliffs and slopes, limestone ledges, solifluction soils +
Flowering May–Jul. +
in A. Gray et al., Syn. Fl. N. Amer. +
Illustrated +
Arabidopsis novae-angliae +, Braya humilis var. abbei +, Braya humilis subsp. arctica +, Braya humilis var. arctica +, Braya humilis var. interior +, Braya humilis var. laurentiana +, Braya humilis var. leiocarpa +, Braya humilis var. novae-angliae +, Braya humilis subsp. richardsonii +, Braya humilis subsp. ventosa +, Braya humilis var. ventosa +, Braya intermedia +, Braya novae-angliae +, Braya novae-angliae subsp. abbei +, Braya novae-angliae var. interior +, Braya novae-angliae var. laurentiana +, Braya novae-angliae subsp. ventosa +, Braya richardsonii +, Pilosella novae-angliae +, Pilosella richardsonii +  and Torularia humilis subsp. arctica +
Braya humilis subsp. humilis +
Braya humilis +
subspecies +