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.

Selected References

None.

Lower Taxa

None.

"not" is not a number. "elongated" is not a number."thick" is not a number."dm" is not declared as a valid unit of measurement for this property."dm" is not declared as a valid unit of measurement for this property.

0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
obtuse +  and acute +
James G. Harris +
J. G. Harris +
cuneate +  and attenuate +
Sisymbrium humile +
appendaged +  and unappendaged +
2 cm20 mm <br />0.02 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
0.8 cm8 mm <br />0.008 m <br /> (1 cm10 mm <br />0.01 m <br />) +
not auriculate +
0.5 cm5 mm <br />0.005 m <br /> (2 cm20 mm <br />0.02 m <br />) +
sinuate-dentate +, , +  and entire +
lobed +, dentate +  and sinuate +
sublinear;oblong;sublinear;oblong;oblanceolate;spatulate;obovate +
smaller +
0.1 cm1 mm <br />0.001 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
urceolate +, campanulate +  and tubular +
branched +  and simple +
well-developed +
not +  and distinct +
not +  and differentiated +
emarginate +  and entire +
incumbent +  and accumbent +
subsessile +  and sessile +
0.8 cm8 mm <br />0.008 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
ascending +  and erect +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
Alta. +  and B.C. +
1500-3000 m +
straight +  and curved +
not winged +  and unappendaged +
0.3 cm3 mm <br />0.003 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
connate +  and distinct +
not basally +  and dilated +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
actinomorphic +
latiseptate +  and sessile +
2.5 cm25 mm <br />0.025 m <br /> (3.2 cm32 mm <br />0.032 m <br />) +
0.18 cm1.8 mm <br />0.0018 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
1.2 cm12 mm <br />0.012 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
torulose +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
Sandy gravelly riverbanks and floodplains, sometimes on slopes and glacial moraines +
sessile +  and petiolate +
alternate +, not +  and rosulate +
cauline +  and basal +
connate +  and distinct +
decurrent +
pinnatifid;sinuate-dentate;pinnatifid;sinuate-dentate +
tenuinucellate +, crassinucellate +  and bitegmic +
campylotropous +  and anatropous +
0.67 cm6.7 mm <br />0.0067 m <br /> (0.72 cm7.2 mm <br />0.0072 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.42 cm4.2 mm <br />0.0042 m <br />) +
4.9mm;6.7mm +
rudimentary +
spatulate +, oblanceolate +  and obovate +
0.23 cm2.3 mm <br />0.0023 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Flowering May–Jul. +
trinucleate +  and 3(-11)-colpate +
ascending +  and erect +
slender +
mucilaginous +
uniseriate +  and biseriate +
not +  and mucilaginous +
white +, black +, brown +  and yellow +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.09 cm0.9 mm <br />9.0e-4 m <br />) +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
persistent +  and caducous +
distinct +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
not fenestrate +
reduced +
latiseptate +  and sessile +
terete +, torulose +, globose +, lanceoloid-subulate +, lanceoloid +, ovoid +, oval-elliptic +, cylindrical +, oblong +  and linear +
latiseptate +  and sessile +
terete +, torulose +, globose +, lanceoloid-subulate +, lanceoloid +, ovoid +, oval-elliptic +, cylindrical +, oblong +  and linear +
Illustrated +
tetradynamous +
procumbent +  and decumbent +
ascending +  and erect +
usually few +  and several +
2-lobed +  and entire +
subsessile +, sessile +  and petiolate +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
persistent +
distinct +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
glabrescent +  and moderately pubescent +
Neotorularia humilis +  and Torularia humilis +
Braya humilis subsp. maccallae +
Braya humilis +
subspecies +
subsessile +  and short-stalked +
coiled +, 1-7-veined +  and veined +
glabrescent +, , +  and pubescent +
anastomosing +
not +  and scapose +
glabrous +, pilose +  and pubescent +
perennial +, biennial +  and annual +
aquatics +  and terrestrial +
glabrescent +  and pubescent +