Myosoton

Moench

Methodus, 225. 1794.

Common names: Giant or water chickweed stellaire aquatique
Etymology: Greek myos, mouse, and otos, ear, alluding to leaves
Treatment appears in FNA Volume 5. Treatment on page 95. Mentioned on page 4, 7, 96, 97.
 TaxonIllustrator 
FNA5 P12 Moenchia erecta.jpegMoenchia erecta
Holosteum umbellatum subsp. umbellatum
Myosoton aquaticum
Barbara Alongi
Barbara Alongi
Barbara Alongi

Herbs, perennial. Taproots slender, rhizomes slender. Stems decumbent to ascending, simple or branched, terete to angular. Leaves sessile leaves clasping proximally, petiolate (proximal leaves) or sessile (most cauline leaves); blade 1-veined, ovate to broadly elliptic, not succulent, apex acute. Inflorescences axillary or terminal, open cymes; bracts paired, foliaceous, smaller. Pedicels ascending to erect, reflexed in fruit. Flowers bisexual, occasionally pistillate or reduced and sterile; perianth and androecium weakly perigynous; hypanthium minimal; sepals 5, distinct, green, ovate, 4–6 (–9) mm, herbaceous, margins green or white, herbaceous or scarious, apex acute, not hooded; petals 5, white, claw absent, blade apex deeply 2-fid; nectaries at base of filaments opposite sepals; stamens 10, occasionally fewer, arising from nectariferous disc at ovary base; filaments distinct; staminodes sometimes present, linear; styles 5 (–6), distinct, filiform, 0.7–1.8 mm, glabrous proximally; stigmas 5 (–6), linear along adaxial surface of styles, papillate (30×). Capsules ovoid to globose-ovoid, opening by 5 (–6), slightly recurved, briefly 2-fid valves; carpophore absent. Seeds 50–100, brown-blackish, reniform, laterally compressed, papillate, marginal wing absent, appendage absent. x = 14.

Distribution

Introduced; Europe, temperate Asia

Discussion

Species 1.

The combination of 5(–6) styles and a capsule opening by the same number of briefly 2-fid valves characterizes Myosoton and is not known in Stellaria. Most chromosome counts of M. aquaticum are 2n = 28, a very rare number in Stellaria.

Selected References

None.

Lower Taxa

... more about "Myosoton"
acute;acute +
Richard K. Rabeler +
Moench +
ovate +  and broadly elliptic +
not succulent +
smaller +
herbaceous +  and scarious +
ovoid;globose-ovoid +
Giant or water chickweed +  and stellaire aquatique +
dish--shaped +
expanded +
Europe +  and temperate Asia +
straight +  and curved +
central +  and peripheral +
Greek myos, mouse, and otos, ear, alluding to leaves +
inconspicuous +
sterile +  and bisexual +
reduced +
stalked +  and simple +
disc--shaped +  and dish +
terminal +  and axillary +
sessile +  and petiolate +
connate +
white +  and green +
scarious +  and herbaceous +
swollen +
3 +  and 5 +
crassinucellate +  and bitegmic +
campylotropous +
reflexed;ascending;erect +
fugacious +
brown-blackish +
papillate +
compressed +  and reniform +
0.6 cm6 mm <br />0.006 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
persistent +
distinct +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
fewer +  and 10 +
branched +  and simple +
decumbent;ascending +
terete;angular +
[30 +  and 5 +
papillate +
distinct +
filiform +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
Myosoton +
Caryophyllaceae subfam. Alsinoideae +
divided +
10 +  and 8 +
rhizomatous +  and taprooted +
pubescence of simple hairs or stalked glands +  and glabrous +