From the Latin and a reference to the Centaur Chiron who was supposed to have discovered the medicinal uses of a plant in Greece that came to be called Centaury
The PlantzAfrica website says that the name of the genus Stoebe is from the Greek stoibe, “stuffing, padding or heap.” It was apparently used for packing wine jars and making brooms and bedding. Umberto Quattrocchi gives the following, also for the genus Stoebe: “Greek steibein, stibo “to tread firmly,” stoibe “thorny burnet, a species of Poterium,” Latin stoebe, es for a plant, called also pheos (Plinius).” From David Hollombe: “stoibe, name used by Dioscorides for Poterium spinosum, also meaning a cushion or pad”
Spotted knapweed, native to eastern Europe, was introduced accidentally to North America in the early 1900s, as a contaminant in seeds for crops. It has since spread prolifically through much of the U.S. and Canada, where it competes with forage plants intended for livestock. It is considered an invasive species in many areas. Forage animals will eat it only as a last resort.
Plants: These attractively flowered but ungainly-looking plants
average about 24" (60 cm) in height and reach up to 5' (1.5 m). They consist of 1-20 branched stems. Stems are dull green, covered with
small rough hairs.
Plants release catechin, a natural herbicide, slowing the growth rate
of competing species, a
trick called allelopathy.
Leaves: The leaves at the base of the plant are somewhat pale,
forming a basal rosette with deeply lobed oval-shaped leaflets up to
8" (20 cm) long, growing alternately from the main
portion of the leaf. Thin stems with many branches form a tangle in the upper part of the plant, with very narrow
leaflets less than 1" (2.5 cm) in length.
Flowers: Pink to purple (rarely white) in color, about ¾" (1.9 cm) in diameter, with each petal branching several times. The “spotted” in spotted knapweed is the brown tips on
the bracts forming the urn-shaped structure beneath the flowers, for example, in
Fruits: Narrow, erect green pods contain seeds that are
¹/₁₆" (2.5 mm) long, oval, and shiny black or brown with pale, vertical lines. A short pappus
forms a micro-parachute at the tip of each seed.
Spotted knapweed flowers bear a superficial resemblance to those of ragged robin: both disheveled-looking,
both similar in hue. If you look
closely, though, knapweeds are composite flowers (like other members of the large aster family)—they
are composed of ray flowers and disc flowers. Ragged robin flowers have petals, but no central disc.
Composite flowers, such as daisies, are typically composed of a central disc containing many small tubular disc flowers, surrounded by flat ray flowers. The ray flowers are often called petals, but each “petal” is actually a complete flower. Some composite flowers have only disc or ray flowers. “Composite” designates an aggregation of many small flowers that resembles a single flower, rather than two different types of flowers. The involucral bract is sometimes an important identifying feature—for example, this is where the spots are in spotted knapweed. Finally, the receptacle is where the parts of a flower head come together.