Minuartia dawsonensis

(Britton) House

Amer. Midl. Naturalist 7: 132. 1921.

Common names: Rock stitchwort minuartie de Dawson
Endemic
Basionym: Arenaria dawsonensis Britton Bull. New York Bot. Gard. 2: 169. 1901
Synonyms: Alsinopsis dawsonensis (Britton) Rydberg Arenaria litorea Fernald Arenaria stricta var. dawsonensis (Britton) Scoggan Arenaria stricta var. litorea (Fernald) B. Boivin Minuartia litorea (Britton) Rydberg Sabulina dawsonensis
Treatment appears in FNA Volume 5. Treatment on page 123. Mentioned on page 120.

Plants perennial, sometimes mat-forming, green. Taproots filiform to somewhat thickened. Stems erect to ascending, green, 4–30 cm, glabrous, internodes of flowering-stems 1–10 times as long as leaves. Leaves overlapping or crowded proximally, variably spaced distally, connate proximally, with tight, scarious to herbaceous sheath 0.2–0.5 mm; blade straight to slightly outwardly curved, green, flat, 1-veined, occasionally 3-veined abaxially, linear to subulate, 4–15 × 0.5–2 mm, flexuous, margins not thickened, scarious, smooth, apex green or purple, mostly rounded, slightly navicular, shiny, glabrous; axillary leaves present among proximal cauline leaves. Inflorescences 7–15-flowered (rarely fewer), open cymes; bracts subulate, herbaceous. Pedicels 0.3–2.5 cm, glabrous. Flowers: hypanthium disc-shaped; sepals prominently 3-veined, ovate to broadly lanceolate (herbaceous portion ovate to broadly lanceolate), 2.5–3.2 mm, to 4 mm in fruit, apex green to purple, acute to apiculate, not hooded, glabrous; petals lancolate to spatulate, 0.5–0.8 times as long as sepals, apex rounded, entire, or petals absent. Capsules on stipe ca. 0.2 mm, ovoid, 3.5–4.5 mm, longer than sepals. Seeds dark-brown to black, suborbiculate with radicle prolonged into tiny beak, 0.5–0.6 mm, tuberculate; tubercles low, rounded, somewhat elongate. 2n = 30, 60.


Phenology: Flowering late spring–summer.
Habitat: Moist, calcareous ledges and gravelly areas (dry, open, and sometimes disturbed slopes, calcareous-gravel raised beach ridges, thin soil over limestone) in mesic forest openings and meadows in montane and subalpine areas and boreal plains, dry, open outcrops in oak or juniper savannas or prairies
Elevation: 0-900 m

Distribution

V5 250-distribution-map.gif

Alta., B.C., Man., Nfld. and Labr., N.W.T., Nunavut, Ont., Que., Sask., Yukon, Alaska, Mich., Minn., N.Dak., Wis.

Discussion

Although sometimes included in Minuartia michauxii [e.g., H. J. Scoggan’s (1978–1979, part 3) treatment of Arenaria stricta], M. dawsonensis is more closely related to the circumpolar M. stricta.

Minuartia litorea, known from Quebec and Ontario, may deserve recognition. An unpublished chromosome count suggests that it is a recent allopolyploid derived from M. dawsonensis and M. rubella (L. Brouillet, pers. comm.).

Selected References

None.

Lower Taxa

None.

"-10timesaslongasleaves" is not declared as a valid unit of measurement for this property."-0.8timesaslongassepals" is not declared as a valid unit of measurement for this property.

... more about "Minuartia dawsonensis"
green +  and purple +
Richard K. Rabeler +, Ronald L. Hartman +  and Frederick H. Utech +
(Britton) House +
Arenaria dawsonensis +
3-veined +  and 1-veined +
flexuous +, straight +  and slightly outwardly curved +
0.4 cm4 mm <br />0.004 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
linear +  and subulate +
? (?) +  and ? (?) +
0.5mm;2mm +
subulate +
reduced +
scarious +  and herbaceous +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
Rock stitchwort +  and minuartie de Dawson +
axillary +  and terminal +
dish--shaped +
expanded +
Alta. +, B.C. +, Man. +, Nfld. and Labr. +, N.W.T. +, Nunavut +, Ont. +, Que. +, Sask. +, Yukon +, Alaska +, Mich. +, Minn. +, N.Dak. +  and Wis. +
0-900 m +
straight +  and curved +
central +  and peripheral +
axillary +  and terminal +
inconspicuous +
unisexual +  and bisexual +
stalked +  and simple +
Moist, calcareous ledges and gravelly areaMoist, calcareous ledges and gravelly areas (dry, open, and sometimes disturbed slopes, calcareous-gravel raised beach ridges, thin soil over limestone) in mesic forest openings and meadows in montane and subalpine areas and boreal plains, dry, open outcrops in oak or juniper savannas or prairiesops in oak or juniper savannas or prairies +
disc--shaped +  and dish +
sessile +  and petiolate +
spaced +, crowded +  and overlapping +
connate +
not thickened +
swollen +
3 +  and 5 +
crassinucellate +  and bitegmic +
campylotropous +
reflexed;erect;arcuate-spreading +
0.3 cm3 mm <br />0.003 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
Lilac (?) +, Pink (?) +  and White (?) +
fugacious +
Flowering late spring–summer. +
Amer. Midl. Naturalist +
prolonged +
tuberculate +
suborbiculate +
0.6 cm6 mm <br />0.006 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
persistent +
distinct +
ovate;broadly lanceolate +
0 cm0 mm <br />0 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
scarious +  and herbaceous +
branched +  and simple +
erect;ascending +
4 cm40 mm <br />0.04 m <br /> (30 cm300 mm <br />0.3 m <br />) +
[30 +  and 3 +
papillate +
0.2 cm2 mm <br />0.002 m <br /> (?) +
distinct +
filiform +
0.06 cm0.6 mm <br />6.0e-4 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Alsinopsis dawsonensis +, Arenaria litorea +, Arenaria stricta var. dawsonensis +, Arenaria stricta var. litorea +, Minuartia litorea +  and Sabulina dawsonensis +
Minuartia dawsonensis +
Minuartia +
species +
divided +
elongate +  and rounded +
10 +  and 8 +
erect +  and recurved +
rhizomatous +  and taprooted +
plant +  and mat-forming +
pubescence of simple hairs or stalked glands +  and glabrous +
23 +, 15 +, 14 +, 13 +, 12 +, 10 +, 9 +  and 7 +