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.

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 +