Cerastium semidecandrum

Linnaeus

Sp. Pl. 1: 438. 1753.

Common names: Five-stamen mouse-ear chickweed
Introduced
Treatment appears in FNA Volume 5. Treatment on page 90. Mentioned on page 75, 83, 89.
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Plants annual, with slender taproot. Stems erect or ascending, branching at base, 1–20 cm, viscid, covered with short, dense, glandular and eglandular hairs; short axillary tufts of leaves absent. Leaves not marcescent, sessile but proximal leaves often spatulate; blade 5–18 × 2–5 mm, covered with short, white hairs; basal leaves with blade narrowly oblanceolate and ± spatulate, apex obtuse; cauline with blades ovate to elliptic-oblong, apex obtuse to acute. Inflorescences open, 3–30-flowered cymes; bracts lanceolate, with broad, scarious margins, glandular-pubescent. Pedicels curved at apex, often sharply angled at base, 3–8 (–12) mm, 1–3 times as long as capsule, densely glandular-pubescent and viscid. Flowers: sepals narrowly lanceolate, 3–5 mm, margins broad, apex acute, glandular-pubescent; petals with unbranched veins, oblanceolate, 2–3 mm, shorter than sepals, apex notched; stamens 5; styles 5. Capsules cylindric, slightly curved, 4.5–6.5 mm, 1.5–2 times as long as sepals; teeth 10, erect, margins convolute. Seeds pale yellowish-brown, 0.4–0.6 mm, finely tuberculate; testa not inflated. 2n = 36.


Phenology: Flowering spring.
Habitat: Common weed in dry, sandy, and gravelly places, roadsides and footpaths, parking lots, dunes
Elevation: 0-300 m

Distribution

V5 186-distribution-map.gif

Introduced; B.C., N.S., Ont., Ark., Conn., Fla., Ga., Idaho, Ill., Ind., Kans., La., Md., Mass., Mich., Mo., Nebr., N.J., N.Y., N.C., Ohio, Oreg., Pa., R.I., S.C., Wash., Wis., Eurasia

Discussion

The very broad, scarious margins of the sepals and bracts distinguish this small, ephemeral species.

Selected References

None.

Lower Taxa

None.

"-2timesaslongassepals" is not declared as a valid unit of measurement for this property."-3timesaslongascapsule" is not declared as a valid unit of measurement for this property.

... more about "Cerastium semidecandrum"
perigynous +  and hypogynous +
glandular-pubescent +
notched;acute;obtuse;acute +
John K. Morton +
Linnaeus +
elliptic to broadly ovate +  and linear +
0.5 cm5 mm <br />0.005 m <br /> (1.8 cm18 mm <br />0.018 m <br />) +
ovate +  and elliptic-oblong +
not succulent +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
often +  and herbaceous +
glandular-pubescent +
lanceolate +
reduced +
herbaceous +  and scarious +
8 +  and 6 +
cylindric +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
Five-stamen mouse-ear chickweed +
3-30-flowered +
dish--shaped +
expanded +
B.C. +, N.S. +, Ont. +, Ark. +, Conn. +, Fla. +, Ga. +, Idaho +, Ill. +, Ind. +, Kans. +, La. +, Md. +, Mass. +, Mich. +, Mo. +, Nebr. +, N.J. +, N.Y. +, N.C. +, Ohio +, Oreg. +, Pa. +, R.I. +, S.C. +, Wash. +, Wis. +  and Eurasia +
0-300 m +
straight +  and curved +
central +  and peripheral +
pistillate +  and subsessile +
inconspicuous +
unisexual +  and bisexual +
stalked +  and simple +
Common weed in dry, sandy, and gravelly places, roadsides and footpaths, parking lots, dunes +
disc--shaped +  and dish +
not marcescent +
connate +
translucent +  and purplish +
swollen +
3 +  and 5 +
crassinucellate +  and bitegmic +
campylotropous +
0.8 cm8 mm <br />0.008 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
reflexed;erect +
glandular-pubescent +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
perigynous +  and hypogynous +
fugacious +
oblanceolate +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
Flowering spring. +
pale yellowish-brown +
tuberculate +
compressed +  and angular-obovate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
persistent +
distinct +
lanceolate +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Introduced +
ascending;erect +
1 cm10 mm <br />0.01 m <br /> (20 cm200 mm <br />0.2 m <br />) +
subterminal +
[30 +  and 5 +
roughened +  and papillate +
distinct +
clavate +  and filiform +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
rooting +  and rhizomatous +
Cerastium semidecandrum +
Cerastium +
species +
not inflated +
divided +
10 +  and 8 +
rhizomatous +  and taprooted +
pubescence of simple hairs or stalked glands +  and glabrous +
19 +, 18 +, 17 +, 15] +, 13 +  and [9 +