1. Vaccaria hispanica (Mill.) Rauschert (cow herb, cow soapwort, cow cockle)
V. pyramidata Medik.
V. hispanica ssp. pyramidata (Medik.) Holub
Saponaria
vaccaria L.
Map 1501, Pl.
349 h, i
Plants annual.
Stems 20–100 cm long, erect, branched above the midpoint, glabrous and
glaucous. Leaves opposite, clasping or fused basally into a sheath,
short-petiolate (basal leaves) or sessile (stem leaves), lacking axillary
clusters of leaves. Stipules absent. Leaf blades 2–10 cm long, lanceolate to
ovate-lanceolate or oblong, not fleshy, angled to cordate at the base, angled
or tapered to a bluntly or more commonly sharply pointed tip, the surfaces
glabrous, somewhat glaucous. Flowers in terminal open, often flat-topped
panicles, the stalks (0.5–)1.0–3.0(–5.5) cm long, erect or ascending at
flowering and fruiting, the bracts paired and resembling small leaves. Epicalyx
absent. Sepals 5, 9–17 mm long, fused most of their length into a tube, this
more or less cylindrical to narrowly flask-shaped and strongly 5-angled or
winged, each angle or wing with a prominent nerve, whitish green, herbaceous
between the sepals, the lobes obovate to broadly triangular, much shorter than
the tube, angled or short-tapered to a sharply pointed tip, not appearing
hooded or awned, the margins herbaceous and green or more commonly thin and
translucent or purplish-tinged. Petals 5, showy, 1.1–2.2 cm long, oblanceolate
to spatulate, tapered to a relatively broad, membranous, straplike or stalklike
base, the expanded portion 0.3–0.8 cm long, rounded, truncate, or shallowly and
broadly notched at the tip, sometimes appearing slightly uneven or ruffled,
pink or purplish pink, lacking appendages. Stamens 10, the filaments distinct,
attached to the basal portion of the petals. Staminodes absent. Pistil with 1
locule or rarely appearing 2-locular toward the base, with a short stalk 0.5–1.5
mm long. Styles 2(3), each with a stigmatic area along the inner surface.
Fruits capsules, (8–)10–13 mm long, the outer wall layer dehiscing apically by
4(6) ascending or slightly spreading teeth, the inner layer dehiscing
irregularly. Seeds 8–12, 2.0–2.5 mm wide, subglobose, the surface with
papillae, black, lacking wings or appendages. 2n=30. May–September.
Introduced,
uncommon and sporadic (native of Europe, Asia; introduced nearly worldwide).
Railroads, roadsides, and open, disturbed areas.
The taxonomy of Vaccaria
is still not fully resolved. Botanists have treated it as comprising either
four species or a single species (V. hispanica) with up to four
subspecies (of which ssp. hispanica is the widespread weed). In the United
States, this taxon formerly was more abundant, especially in the plains and
midwestern states, as a crop weed. In recent decades, populations have been
declining, in part due to a combination of improved grain handling and the more
widespread application of herbicides. However, in Missouri it does not appear
ever to have been very common. Mühlenbach (1979) noted that it was rarely
observed in his botanical inventory of the St. Louis railyards, often as only 1–3
individuals at a site. The seeds of Vaccaria contain saponins and are
poisonous (Burrows and Tyrl, 2001).