Noccaea arctica

(A. E. Porsild) Holub

Preslia 70: 107. 1998.

Basionym: Thlaspi arcticum A. E. Porsild Sargentia 4: 40. 1943
Treatment appears in FNA Volume 7. Treatment on page 601.
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Perennials; (with persistent petiolar remains). Stems simple or several from caudex, erect, unbranched, 0.5–1.8 dm. Basal leaves: petiole 0.4–1.3 cm; blade oblanceolate to spatulate, 0.3–1.8 cm × 2–4 mm, base cuneate or attenuate, margins entire, apex obtuse. Cauline leaves 3–7; blade ovate or suboblong, 0.5–1 cm × 1–5 mm, base minutely auriculate, margins entire, apex obtuse to subacute. Racemes 0.5–6 cm. Fruiting pedicels ascending to horizontal, straight, 3–8 mm. Flowers: sepals 1.5–2.5 × 0.5–1 mm, (margins white); petals white, 3–5 × 2–2.5 mm, often flaring between blade and claw, apex rounded; filaments 2–3 mm; anthers ca. 0.5 mm. Fruits not winged, narrowly obovate, 6–10 × 2–3.5 mm, base cuneate, apex obtuse; ovules 8–14 per ovary; style (0.3–) 0.6–1 mm. Seeds yellowbrown, 1.5–2 mm, nearly smooth. 2n = 14.


Phenology: Flowering Jun–Aug.
Habitat: Dry tundra ridges, arctic coast
Elevation: 0-500 m

Discussion

Noccaea arctica is rare, known from a limited number of collections. P. K. Holmgren (1971) suggested that additional collections might indicate that it is a variety of N. fendleri (as Thlaspi montanum).

Selected References

None.

Lower Taxa

None.

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

... more about "Noccaea arctica"
0.5 cm5 mm <br />0.005 m <br /> (?) +
obtuse +, rounded +  and subacute +
Ihsan A. Al-Shehbaz +
(A. E. Porsild) Holub +
cuneate +, auriculate +  and attenuate +
Thlaspi arcticum +
appendaged +  and unappendaged +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
dissected +, repand +, sinuate +, crenate +  and dentate +
suboblong;ovate;oblanceolate;spatulate +
much smaller +  and reduced +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
urceolate +, campanulate +  and tubular +
branched +  and simple +
well-developed +
differentiated +
emarginate +  and entire +
Yukon +  and Alaska. +
0-500 m +
straight +  and curved +
not winged +  and unappendaged +
connate +  and distinct +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
actinomorphic +
0.6 cm6 mm <br />0.006 m <br /> (1 cm10 mm <br />0.01 m <br />) +
obovate +
0.2 cm2 mm <br />0.002 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
angustiseptate +
Dry tundra ridges, arctic coast +
sessile +  and petiolate +
alternate +, not +  and rosulate +
cauline +  and basal +
connate +  and distinct +
decurrent +
dentate;denticulate;dentate;denticulate;entire +
1 +, 4 +  and 2 +
tenuinucellate +, crassinucellate +  and bitegmic +
campylotropous +  and anatropous +
rudimentary +
flaring +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
Flowering Jun–Aug. +
trinucleate +  and 3(-11)-colpate +
ascending +  and horizontal +
slender +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
mucilaginous +
aseriate +, biseriate +  and uniseriate +
not +  and mucilaginous +
yellowbrown +
ovoid +  and compressed +
0.15 cm1.5 mm <br />0.0015 m <br /> (?) +  and 0.2 cm2 mm <br />0.002 m <br /> (?) +
persistent +  and caducous +
distinct +
ovate +  and oblong +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
reduced +
latiseptate +, schizocarpic +, samaroid +  and lomentaceous +
indehiscent +  and dehiscent +
angustiseptate +, flat +, angled +, terete +, torulose +, not +, segmented +  and nutletlike +
tetradynamous +
unbranched +  and simple +
procumbent +  and decumbent +
2-lobed +, entire +, conical +  and capitate +
subsessile +, sessile +  and petiolate +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
persistent +
distinct +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
Cruciferae +
Noccaea arctica +
species +
eglandular +, peltate +, malpighiaceous +, dendritic +, sessile +, stalked +, simple +  and unicellular +
scale-like +  and forked +
pubescent +  and glabrous +
anastomosing +
rhizomatous +, taprooted +, scapose +  and not +
perennial +, biennial +  and annual +
subshrub +  and herb +
aquatics +  and terrestrial +
glabrous +  and pubescent +