Minuartia obtusiloba

(Rydberg) House

Amer. Midl. Naturalist 7: 132. 1921.

Common names: Twin-flower sandwort alpine stitchwort
Illustrated
Basionym: Alsinopsis obtusiloba Rydberg Bull. Torrey Bot. Club 33: 140. 1906,
Synonyms: Alsinopsis obtusiloba (Rydberg) Fernald Lidia obtusiloba (Rydberg) Á. Löve & D. Löve
Treatment appears in FNA Volume 5. Treatment on page 131. Mentioned on page 118, 119, 120, 121.

Plants perennial, cespitose to mat-forming. Taproots stout, woody. Stems erect, green, 1–12 cm, trailing stems 2–20+ cm, stipitate-glandular, internodes of flowering-stems 1–6 times as long as leaves. Leaves tightly overlapping (vegetative), variably spaced (cauline), usually connate proximally, with tight, scarious to herbaceous sheath 0.3–1.5 mm; blade straight to outwardly curved, green, 3-angled, 3-veined abaxially, midrib prominent, lateral-veins weak in distal 1/3, needlelike to subulate, 1–8 × 0.4–1 mm, flexuous, margins not thickened, herbaceous, sometimes finely ciliate, apex green, rounded to acute, often apiculate, somewhat navicular, shiny, glabrous; axillary leaves present among vegetative leaves. Inflorescences solitary flowers, terminal, or occasionally in 2–3-flowered, open cymes; bracts subulate, herbaceous. Pedicels 0.3–1.5 cm, stipitate-glandular. Flowers: hypanthium cupshaped; sepals prominently 3-veined proximally, narrowly ovate to oblong (herbaceous portion lanceolate to oblong), 2.9–6.5 mm, not enlarging in fruit, apex often purple, narrowly rounded, hooded; petals ovate to spatulate, 1.2–2 times as long as sepals, apex rounded, entire. Capsules narrowly ellipsoid, 3.5–6 mm, equaling sepals. Seeds reddish tan, suborbiculate with radicle prolonged into beak, somewhat compressed, 0.6–0.7 mm, obscurely sculptured (50×). 2n = 26, ca. 52, 78.


Phenology: Flowering summer.
Habitat: Dwarf willow communities, fell-fields, snow beds in subalpine and alpine areas
Elevation: 0-4000 m

Distribution

V5 269-distribution-map.gif

Alta., B.C., N.W.T., Yukon, Alaska, Ariz., Calif., Colo., Idaho, Mont., Nev., N.Mex., Oreg., Utah, Wash., Wyo., Asia (Russian Far East)

Discussion

Minuartia obtusiloba, an amphi-Beringian species, sometimes forms hybrid swarms with M. arctica. Specimens labeled Arenaria sajanensis Willdenow ex Schlechtendal from western North America, sometimes referred to M. biflora (e.g., H. J. Scoggan 1978–1979, part 3), are likely to be M. obtusiloba.

Selected References

None.

Lower Taxa

None.

"-6timesaslongasleaves" is not declared as a valid unit of measurement for this property."-2timesaslongassepals" is not declared as a valid unit of measurement for this property.

... more about "Minuartia obtusiloba"
78 +, 52 +  and 26 +
entire +  and apiculate +
Richard K. Rabeler +, Ronald L. Hartman +  and Frederick H. Utech +
(Rydberg) House +
Alsinopsis obtusiloba +
straight +  and outwardly curved +
3-angled +
? (?) +  and ? (?) +
subulate +
reduced +
scarious +  and herbaceous +
ellipsoid +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
Twin-flower sandwort +  and alpine stitchwort +
open +  and 2-3-flowered +
axillary +  and terminal +
dish--shaped +
expanded +
Alta. +, B.C. +, N.W.T. +, Yukon +, Alaska +, Ariz. +, Calif. +, Colo. +, Idaho +, Mont. +, Nev. +, N.Mex. +, Oreg. +, Utah +, Wash. +, Wyo. +  and Asia (Russian Far East) +
0-4000 m +
straight +  and curved +
central +  and peripheral +
axillary +  and terminal +
inconspicuous +
unisexual +  and bisexual +
stalked +  and simple +
Dwarf willow communities, fell-fields, snow beds in subalpine and alpine areas +
disc--shaped +  and dish +
0.1 cm1 mm <br />0.001 m <br /> (?) +  and 0.8 cm8 mm <br />0.008 m <br /> (?) +
needlelike +  and subulate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
sessile +  and petiolate +
spaced +  and overlapping +
connate +
not thickened +
swollen +
3 +  and 5 +
crassinucellate +  and bitegmic +
campylotropous +
reflexed;erect;arcuate-spreading +
stipitate-glandular +
0.3 cm3 mm <br />0.003 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
Lilac (?) +, Pink (?) +  and White (?) +
fugacious +
Ovate (?) +  and Spatulate (?) +
Flowering summer. +
Amer. Midl. Naturalist +
prolonged +
sculptured +
compressed +  and suborbiculate +
0.6 cm6 mm <br />0.006 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
persistent +
distinct +
narrowly ovate;oblong +
not enlarging +
0.29 cm2.9 mm <br />0.0029 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
scarious +  and herbaceous +
Illustrated +
branched +  and simple +
trailing;erect +
2 cm20 mm <br />0.02 m <br /> (20 cm200 mm <br />0.2 m <br />) +
[30 +  and 3 +
papillate +
distinct +
filiform +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Alsinopsis obtusiloba +  and Lidia obtusiloba +
Minuartia obtusiloba +
Minuartia +
species +
divided +
10 +  and 8 +
erect +  and recurved +
rhizomatous +  and taprooted +
plant +, cespitose +  and mat-forming +
pubescence of simple hairs or stalked glands +  and glabrous +
23 +, 15 +, 14 +, 13 +, 12 +, 10 +, 9 +  and 7 +