Braya humilis subsp. maccallae

J. G. Harris

Novon 16: 346. 2006

Treatment appears in FNA Volume 7. Treatment on page 550. Mentioned on page 549.
Stems ascending to erect, often unbranched, 0.4–2.3 dm, moderately pubescent. Leaves: blade margins entire or, sometimes, sinuate-dentate, surfaces glabrescent to moderately pubescent. Flowers: petals white, (4.4–)4.9–6.7(–7.2) × (2.1–)2.3–4(–4.2) mm. Fruits often abortive, somewhat torulose, 0.7–1.2 mm wide when fully developed; septum not fenestrate or split longitudinally. 2n = 28.

Phenology: Flowering May–Jul.
Habitat: Sandy gravelly riverbanks and floodplains, sometimes on slopes and glacial moraines
Elevation: 1500-3000 m

Discussion

Subspecies maccallae differs from subspp. elesmerensis and humilis in having leaf margins mostly entire, flowers exceptionally large, and a high percentage of abortive fruit. Cauline leaves are much reduced and arise from the base of the stem, giving an almost acaulescent appearance to the plant. Breeding studies (J. G. Harris 1985) indicate that subspp. maccallae and porsildii are self-incompatible, while most subspecies of Braya humilis are strongly autogamous.

References

None.

Lower Taxa

No lower taxa listed.