Convolvulus arvensis L.
Family - Convolvulaceae
Stems - Trailing, twining, herbaceous, glabrous to pubescent, appearing 4-5 angled because of twisting of stem.
Leaves - Alternate, petiolate,
variable in shape from ovate to elliptic, to 10cm long, +/-5cm broad, hastate
to sagittate or cordate. Petiole to +3cm long, with adaxial groove, pubescent
to glabrous. Blade glabrous or pubescent. Basal lobes acute to obtuse.
Leaf margins often undulate.
Inflorescence - Flowers either
single or in loose cymes of up to 3 flowers. Peduncle to +6cm long, with
opposite to subopposite pair of bracts at apex(subtending pedicels), pubescent.
Bracts to +4mm long. Pedicels to -2cm long, with pair of opposite to subopposite
bracts in middle, pubescent to tomentose. Bracts to +/-3mm long, linear.
Calyx.
Flowers - Corolla funnelform,
white or tinged with pink, to +/-3cm broad, -2cm long, glabrous internally,
glabrous to sparse puberulent externally. Stamens 5, adnate at base of
corolla tube. Filaments to 1cm long, flattened and broad at base(to 1.2mm
broad), terete above, clavate pubescent near base, white. Anthers whitish-pink,
to 3mm long. Style white, glabrous, 1cm long. Stigmas 2, 3-4mm long, white
to pale yellow. Ovary subtended(surrounded) by orange nectar ring. Ovary
white, glabrous to pubescent, superior, 2mm long, 2-locular. Sepals 5,
green and often with tiny brownish tip, glabrous, 4mm long, 2.1mm broad,
scarious near apex, distinct. Fruit a glabrous 4-valved capsule to +/-6mm
long.
Flowering - May - September.
Habitat - Waste ground, disturbed sites, roadsides, railroads.
Origin - Native to Europe and Asia.
Other info. - According to
Steyermark there are two forms in Missouri. Form arvensis
(pictured above) has lobes at the base of the leaves being pointed (acutely),
the leaf blade itself can be from sagittate to ovate-triangular. Form cordifolius
has lobes which are rounded and a broad cordate leaf blade.
This species is quite common and
weedy. It primarily stays low or on the ground but can climb by twining.
The species name "arvensis" means "from cultivated
fields" or "of cultivated fields" telling of the plants pioneering and
invasive nature.
The pubescence of the plant is highly variable.
Photographs taken in Springfield, MO., 7-5-03.
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