Transberingia bursifolia

(de Candolle) Al-Shehbaz & O’Kane

Novon 13: 396. 2003.

Basionym: Nasturtium bursifolium de Candolle Syst. Nat. 2: 194. 1821
Synonyms: Arabidopsis bursifolia (de Candolle) Botschantzev Beringia bursifolia (de Candolle) R. A. Price, Al-Shehbaz & O’Kane
Treatment appears in FNA Volume 7. Treatment on page 456.

Plants densely hirsute basally, trichomes primarily simple, to 1 mm, these often mixed with smaller, forked, and/or dendritic ones, glabrescent or sparsely pubescent distally. Stems simple or few to several from caudex, (0.5–)1–4.5(–6.5) dm. Basal leaves: petiole 0.3–3 cm, flattened at base, ciliate; blade oblanceolate to obovate, or linear-lanceolate, (0.5–)1.2–6.5(–10) cm × (2–)3–8(–17) mm, base cuneate to attenuate, apex obtuse to subacute, surfaces pubescent, trichomes usually branched. Cauline leaves: blade lanceolate to linear-lanceolate or oblong, (0.5–)1–3(–4.2) cm × (1–)2.5–7(–10) mm, base strongly sagittate. Fruiting pedicels not appressed to rachis, straight, (3–)5–14(–18) mm, glabrous. Flowers: sepals 1.2–2.5 × 0.6–1 mm, sparsely to densely pubescent; petals (2.5–)3–4(–4.5) × (0.8–)1–1.5 mm; filaments 2–2.5 mm; anthers 0.4–0.5 mm. Fruits (1.5–)2–3.3(–4) cm × (0.7–)1–1.5(–2) mm; style slender, 0.2–0.8(–1) mm. Seeds 0.8–1 × 0.4–0.5 mm.

Distribution

V7 696-distribution-map.gif

Alta., N.W.T., Nunavut, Sask., Yukon, Alaska, Calif., Colo., Idaho, Mont., Nev., Utah, Wyo., e Asia (Russian Far East).

Discussion

Subspecies 2 (2 in the flora).

R. C. Rollins (1993) treated subspp. bursifolia and virgata as distinct species of Halimolobos, but the alleged differences (stems branched basally versus distally, plants cespitose versus non-cespitose, fruits slightly compressed versus terete) do not hold, and the only reliable difference between the two taxa is in the type of trichomes. Therefore, a subspecific, rather than specific, rank is adopted here.

Selected References

None.

Key

1 Plants glabrous or sparsely pubescent on stems distally and on rachises, trichomes simple, spreading. Transberingia bursifolia subsp. bursifolia
1 Plants usually pubescent, rarely glabrescent, on stems distally and on rachises, trichomes branched, subappressed, these sometimes mixed with simple ones. Transberingia bursifolia subsp. virgata
... more about "Transberingia bursifolia"
Ihsan A. Al-Shehbaz +
(de Candolle) Al-Shehbaz & O’Kane +
Nasturtium bursifolium +
Alta. +, N.W.T. +, Nunavut +, Sask. +, Yukon +, Alaska +, Calif. +, Colo. +, Idaho +, Mont. +, Nev. +, Utah +, Wyo. +  and e Asia (Russian Far East). +
Arabidopsis bursifolia +  and Beringia bursifolia +
Transberingia bursifolia +
Transberingia +
species +